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Amylase
Kinds of Amylase Terms modified by Amylase Selected AbstractsINHIBITORY POTENTIAL OF WINE AND TEA AGAINST ,-AMYLASE AND ,-GLUCOSIDASE FOR MANAGEMENT OF HYPERGLYCEMIA LINKED TO TYPE 2 DIABETESJOURNAL OF FOOD BIOCHEMISTRY, Issue 1 2008YOUNG-IN KWON ABSTRACT Natural ,-amylase and ,-glucosidase inhibitors from food-grade plants offer an attractive strategy to manage postprandial hyperglycemia for type 2 diabetes management via control of starch breakdown and intestinal glucose absorption. In this study, four random sources of red and white wines as well as four types of teas were investigated for ,-amylase and ,-glucosidase inhibitory potential. Water extracts of black tea had the highest ,-glucosidase inhibitory activity, followed by white tea and oolong tea. All the randomly selected red wines had significant ,-glucosidase inhibitory activity compared to white wine. The ,-glucosidase inhibitory activity of the tea and wines correlated to the phenolic content, antioxidant activity and phenolic profile of the extracts. Further, these extracts had less or no ,-amylase inhibitory activity, indicating potential to overcome the side effects of undigested starch. This research has relevance for managing hyperglycemia and related oxidation-linked dysfunction and concurrently reducing problems of undigested starch. PRACTICAL APPLICATIONS In this study anti-diabetic-relevant potential of wines and teas were confirmed in four types of red and white wines as well as four types of commonly available teas using in vitro enzyme assays for alpha-glucosidase and alpha-amylase inhibitory activities. In vitro inhibitory activities of these enzymes provide a strong biochemical rationale for further in vivo studies and dietary management strategy for type 2 diabetes through the control of glucose absorption. Further this phenolic antioxidant-enriched dietary strategy using specific beverage combinations can generate a whole food profile that has the potential to reduce hyperglycemia-induced pathogenesis and also associated complications linked to cellular oxidation stress. [source] EFFECT OF EMULSIFIERS AND FUNGAL , -AMYLASE ON RHEOLOGICAL CHARACTERISTICS OF WHEAT DOUGH AND QUALITY OF FLAT BREADJOURNAL OF FOOD PROCESS ENGINEERING, Issue 2 2009ARASH KOOCHEKI ABSTRACT Teftoon, a flat bread made of whole wheat flour, is prepared by hand sheeting of dough, followed by baking. Different emulsifiers, like lecithin, E471 (distilled monoglyceride) and E472 (diacetylated tartaric acid esters of mono- and digelycerid of fatty acids), were added to the flour at various levels ranging between 0.25 and 1.0% w/w, and it was observed that they improved the dough characteristics. Improvement in bread quality parameters, such as force to tear and sensory acceptability, were monitored. Fungal, -amylase was also incorporated into the flour at 5,20 g/100 kg flour basis alone and in combination with the emulsifier. The force required to tear the fresh bread was decreased with emulsifier and enzyme addition; however, E472 addition at 0.75% w/w of whole wheat flour gave the softest bread. The tear force of stored bread significantly increased with storage; however, bread containing E472 showed a less increase in tear force up to a period of 3 days. The sensory acceptability was found to be higher than that of the control bread for emulsifiers, and lower for enzyme at a concentration higher than 10 g/kg flour. PRACTICAL APPLICATIONS Flat bread is normally consumed fresh, but the staling phenomenon starts immediately after baking this kind of bread. Today, large-scale production and increased consumer demands for high-quality bread with long shelf life have created the need for functional food additives such as emulsifiers and , -amylase enzyme. Incorporation of emulsifiers and enzyme decreased the hardness of Taftoon bread. Emulsifiers and , -amylase enzyme enhanced the flat bread dough quality. The sensory acceptability also improved with the addition of emulsifiers. Optimizing the amount of emulsifiers and enzyme required for reduction of bread hardness is vital because the quality and price of the final product depend on this parameter. [source] EFFECTS OF CO-IMMOBILIZATION OF PECTINASE AND AMYLASE ON ULTRAFILTRATION OF APPLE JUICE SIMULATEJOURNAL OF FOOD PROCESS ENGINEERING, Issue 6 2001MARÍA E. CARRÍN ABSTRACT In view of its possible application in apple juice clarification, the potential of co-immobilized pectinase/amylase by physical adsorption on a polysulfone ultrafiltration hollow fiber was examined. Solutions containing different concentrations of pectin and starch were used. The effect of various operational parameters on the production of reducing compounds, mainly galacturonic acid and maltose, was investigated. Results indicated that relative permeate flux, during ultrafiltration of starch-pectin solutions, was up to 35% higher when commercial pectinase and amylase were co-immobilized on a hollow fiber membrane. Although the concentration of reaction products increased up to 50% with the pectin concentration, the same was not verified when the starch content changed from 3.85 to 5.00 mg/mL. However, the reference permeate flux was improved when starch was added to substrate, independently of its concentration. Considering the size of an average starch granule, this increase in permeate flux was attributed to the removal of pectin gel by dragging. Permeate fluxes were comparable for both batch and permeate recycling operations. [source] PURIFICATION OF AMYLASE FROM TILAPIA BY MAGNETIC PARTICLEJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 1 2010MING CHANG WU ABSTRACT Recent development in magnetic carrier technology involves the use of nonmagnetic substrates attached to superparamagnetic particles forming functionally modified magnetic support to isolate a particular enzyme in a controllable magnetic field. In this study, the superparamagnetic particles were modified by epichlorohydrin and other agents to cross-link with starch to form the purification support. This affinity support was able to bind the amylase and was used in the purification of amylase from Taiwan tilapia. After ammonium sulfate precipitation of amylase from Taiwan tilapia, the modified superparamagnetic particles were able to purify the crude amylase by 20.78-fold with recovery of activity of 75.6%. The molecular weight of the amylase was estimated to be 66.1 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Both crude and purified amylase reached an optimum at a pH of 8.0 and temperature of 50C, and the enzyme was stable between 20 and 50C. PRACTICAL APPLICATIONS Because of the rapid development of high technology such as carrier supports for enzyme purification, the development, research and application of magnetic carriers are timely needed. The present study demonstrated that the affinity superparamagnetic particles could be used as a carrier support to absorb and purify the amylase and that technology of affinity purification can be widely used in protein purification. Compared with the traditional chromatography used in the purification of proteins, this novel affinity superparamagnetic particle technology is rapid, has low operation cost, requires simple facilities, and involves easy separation and recovery of the enzymes. [source] Production of ,-Amylase and Glucoamylase by a New Isolate of Trichoderma sp.ENGINEERING IN LIFE SCIENCES (ELECTRONIC), Issue 4 2004Using Sorghum Starch as a Carbon Source The performance of a new Trichoderma sp. isolate to produce extracellular ,-amylase and glucoamylase from raw sorghum starch was evalutated. To reduce the costs of starch saccharification and the consumption of amylolytic enzymes, this microorganism has been used for the first time in cultivations using such a carbon source without any prior gelatinization. [source] ,1-Antitrypsin deficiency presenting with panniculitis and incidental discovery of chronic obstructive pulmonary diseaseINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 10 2007Gretchen Korver MD A 60-year-old man presented to the Emergency Department (ED) with large, painful, indurated plaques on the right thigh, left abdomen, left chest, and right chest, which began without any preceding trauma on the right thigh 3 weeks prior to presentation in the ED. He was initially treated with cefazolin 1 g three times daily as home infusions. When the lesions continued to progress, he was admitted to the hospital and placed on amoxicillin/clavulanate and vancomycin. He had a single episode of fever of 102°F, but his white blood cell count and differential remained normal. An initial biopsy showed a dermal inflammatory infiltrate composed primarily of neutrophils and eosinophils with rare flame figures in the dermis. There was minimal fat seen in this biopsy. A differential diagnosis of Wells or Sweet's syndrome was entertained, and he was placed on 60 mg/day prednisone with no resolution of his symptoms. The patient's past medical history included hypertension, hyperlipidemia, peripheral neuropathy, and hiatal hernia. His family history was significant for emphysema in both parents and coronary artery disease in his father. Both of his parents smoked cigarettes. His grandfather, who was a coal miner, also had emphysema. Whilst on antibiotics and prednisone, the plaques on the patient's right thigh, right abdomen, and left chest expanded and ulcerated, draining an oily liquid (Figs 1 and 2). An incisional biopsy was obtained from his thigh. Histopathology showed a septal and lobular panniculitis with fat necrosis, neutrophils, and histiocytes (Fig. 3). Special stains for organisms were negative. Tissue sent for bacterial and fungal culture had no growth. Amylase and lipase levels were normal. Rheumatoid factor, antinuclear antibody (ANA), antineutrophil cytoplasmic antibody (ANCA), cryoglobulins, and antiphospholipid antibodies were all normal. The ,1-antitrypsin level was low at 25 mg/dL (ref. 75,135). The ,1-antitrypsin phenotype was PiZZ. Figure 1. Indurated plaques on right chest and thigh and left chest Figure 2. Ulcerated plaques on left chest Figure 3. Septal and lobular panniculitis with fat necrosis. Hematoxylin and eosin ×10 The patient had a normal glucose-6-phosphate dehydrogenase level and was placed on dapsone 200 mg/day. The inflammation resolved and, over the course of several months, the involved areas healed with scarring. The patient denied any pulmonary complaints but, during his hospitalization, was found incidentally to have an oxygen saturation of 88% on room air. He was sent for evaluation by a pulmonologist, and pulmonary function tests revealed a mixed restrictive and obstructive pattern with a forced expiratory volume in 1 to forced vital capacity (FEV1/FVC) ratio of 63% of predicted. He had never smoked. He was placed on supplemental oxygen but, as his pulmonary disease has been stable, he has not been treated with intravenous antitrypsin inhibitor. [source] PRODUCTION AND BIOCHEMICAL CHARACTERIZATION OF SCLEROTINIA SCLEROTIORUM ,-AMYLASE ScAmy1: ASSAY IN STARCH LIQUEFACTION TREATMENTSJOURNAL OF FOOD BIOCHEMISTRY, Issue 5 2008IMEN BEN ABDELMALEK KHEDHER ABSTRACT Among the lytic enzymes secreted by the phytopathogen fungus Sclerotinia sclerotiorum, a starch-degrading activity has been isolated and characterized. Two extracellular ,-amylases were produced in culture medium in presence of oats flour as carbons sources. An endoamylase named ScAmy1 was purified to homogeneity by ammonium sulfate precipitation, phosphocellulose and cation exchange high performance liquid chromatographies. Molecular mass of purified ScAmy1 was estimated as 54 kDa. Amylase exhibits maximal activity at pH 5 to 6 and at temperature 60C. ScAmy1 was stable in a pH range of (5,11) and at 50C. Initial activity was still conserved 40%, after heating at 60C during 30 min. In addition, Ca2+activate and stabilize the enzyme. Starch end products were determined as low molecular oligoglucanes, the liquefying power of ScAmy1 was also tested with the Amylograph Brabender, results suggest a suitable application of ScAmy1 in several industrial process. PRACTICAL APPLICATIONS ,-Amylase ScAmy1 was highly produced from Sclerotinia sclerotiorum on oats flour , a cheaper by-agro-substrate product. The enzyme was purified and biochemical characterized. ScAmy1 was applied in starch liquefaction treatments assay. The enzyme allows a decrease in peak viscosity after gelatinization and therefore has an important liquefying power. ScAmy1 has a nearly liquefaction effect on flour compared to the commercial enzyme Novamyl, from Novozymes, donated by Novo Nordisk Co. (Denmark). Enzyme end products were analyzed and identified as oligoglucanes and dextrins. Those are widely applied in food, paper, textile and pharmacological industries. Oligosaccharides are useful as prebiotics as dietary fiber or slowly digestible starch derivatives, and they can be used in form of supplement to certain foodstuffs. [source] Toward a Microfluidic-Based Rapid Amylase Assay SystemJOURNAL OF FOOD SCIENCE, Issue 6 2009Richard J. Holmes ABSTRACT:, This article describes work into a prototype system for the assay of amylase, using microfludic technologies. The new system has a significantly shorter cycle time than the current laboratory methods, which generally use microtitre plates, yet is capable of generating significantly superior results. As such, we have shown that sensitivity is enhanced by a factor of 10 in the standard assay trials, and by a factor of 2 in the real-sample lab trials. In both assays, the use of a microreactor system reduced the reaction time by a factor of 6.2, from 20 min incubation to 3.2 min. Basing the conclusion on the Megazyme Cerealpha Standard Method, and using the Cerealpha units as a measure of assay efficiency, the typical response for the microfluidic assay was shown to be 1.0 × 10,3 CU/mL (standard deviation [SD] 2.5 × 10,4 CU/mL), compared to 2.56 × 10,4 CU/mL (SD 5.94 × 10,5 CU/mL) for the standard macroassay. It is believed that this improvement in the reaction schematics is due to the inherent advantages of microfluidic devices such as superior mixing, higher thermal efficiency, and enhanced reaction kinetics. [source] Characterization of Honey AmylaseJOURNAL OF FOOD SCIENCE, Issue 1 2007Sibel Babacan ABSTRACT:, The major ,-amylase in honey was characterized. The optimum pH range and temperature were determined for the enzyme as 4.6 to 5.3 and 55 °C, respectively. The enzyme was stable at pH values from 7 to 8. The half-lives of the purified enzyme at different temperatures were determined. The activation energy for heat inactivation of honey amylase was 114.6 kJ/mol. The enzyme exhibited Michaelis,Menten kinetics with soluble starch and gave KM and Vmax values of 0.72 mg/mL and 0.018 units/mL, respectively. The enzyme was inhibited by CuCl (34.3%), MgCl2 (22.4%), and HgCl2 (13.4%), while CaCl2, MnCl2, and ZnSO4 did not have any effect. Starch had a protective effect on thermal stability of honey amylase. Therefore, it might be critical to process or control the amylase in honey before incorporation into starch-containing foods to aid in the preservation of starch functionality. One step could involve heat treating honey with other ingredients, especially those that dilute and acidify the honey environment. [source] Amylase and cyclic amp receptor protein expression in human diabetic parotid glandsJOURNAL OF ORAL PATHOLOGY & MEDICINE, Issue 9 2010Monica Piras J Oral Pathol Med (2010) 39: 715,721 Background:, Salivary dysfunction and oral disorders have been described in both type 1 and type 2 diabetes mellitus. However, the cellular and molecular consequences of diabetes on oral tissues remain to be ascertained. The purpose of this investigation was to study, by means of electron microscopy, the morphologic and molecular changes that occur in salivary glands during diabetes. Methods:, Biopsy samples of parotid glands were excised from non-diabetic and diabetic (type 1 and type 2) consenting patients and processed by standard methods for routine morphology and electron microscopic immunogold labeling. Specific antibodies were used to determine and quantify the expression of secretory proteins (alphaamylase and the regulatory subunit of type II protein kinase A). Results:, Morphologic changes in the diabetic samples included increased numbers of secretory granules, and alterations in internal granule structure. Quantitative analysis of immunogold labeling showed that labeling densities were variable among the parotid gland samples. In type 1 diabetes amylase expression was greater than in non-diabetic glands, whereas in type 2 diabetes it was not significantly changed. Expression of type II regulatory subunits was slightly, although not significantly, increased in acinar secretory granules of type 1 diabetic samples and was unchanged in type 2 diabetic samples. Conclusions:, Our data show that diabetes elicits specific changes in secretory protein expression in human salivary glands, thus contributing to the altered oral environment and oral disease associated with diabetes. [source] Evaluation of carbohydrate rich diets through common carp culture in manured tanksAQUACULTURE NUTRITION, Issue 3 2002P. KESHAVANATH Four diets (T0,T3) were formulated reducing the fishmeal (Indian) component by 100 g kg,1 from 300 to 0 g kg,1 and including proportionately increasing quantities of maize. Diets were fed for 120 days at 50 g kg,1 body weight to triplicate groups of common carp (av. wt. 2.11,2.18 g) stocked at 1 m,2 in mud bottomed cement tanks (18 m2), fertilized with poultry manure. Fish growth, SGR and FCR in the different treatments were statistically not significantly different (P > 0.05). PER was lowest for the 300 g fishmeal kg,1 diet treatment (diet T0), increasing with decrease in dietary fishmeal content (diets T1,T3). Fish survival ranged from 96.29 to 100%. Diets influenced carcass composition and digestive enzyme activity. A significant increase in lipid deposition was recorded with increasing dietary carbohydrate content. Amylase, protease and lipase activities were higher in fish fed with diets T2 and T3. The protein sparing effect of dietary carbohydrate and the economic implication of eliminating fishmeal from the diet are discussed. [source] Effects of dietary protein levels on the growth performance, digestive capacity and amino acid metabolism of juvenile Jian carp (Cyprinus carpio var. Jian)AQUACULTURE RESEARCH, Issue 9 2009Yong Liu Abstract This experiment was conducted to evaluate the effects of protein levels on the growth performance, digestive capacity and amino acid metabolism of juvenile Jian carp. Brown fish meal was used as the sole protein source in the present study. Six isoenergetic experimental diets containing 14.4 MJ kg,1 of digestible energy and 220,495 g crude protein kg,1 diets were fed to triplicate groups of 50 fish with a mean initial weight of 16.67 ± 0.01 g for 45 days. Per cent weight gain (PWG) and feed efficiency ratio (FER) improved with an increase in the dietary protein levels up to 330 g kg,1 diet. The condition factor, relative gut length, intestinal folds height, hepatopancreas and intestine protein content improved with an increase in the protein levels up to 330,385 g kg,1 diet. Trypsin, creatinkinase, Na+, K+ -ATPase and alkaline phosphatase activities generally followed the same tendency as that of growth parameters. Amylase and ,-glutamyl transpeptidase (,-GT) activities were negatively correlated with increasing protein levels from 220 to 330 g kg,1 diet, and no differences were found thereafter. Lipase activity was unaffected by protein levels. Lactobacillus amount was increased with protein levels up to 275 g kg,1 diet, while Aeromonas amount followed the opposite pattern. Escherichia coli amount was not influenced by dietary protein levels. Glutamate,oxaloacetate transaminase (GOT) activities in the hepatopancreas and plasma ammonia concentration (PAC) were not influenced by protein levels between 220 and 275 g kg,1 diet, but significantly increased with increasing protein levels from 275 to 440 g kg,1 diet, and remained similar thereafter. Glutamate,pyruvate transaminase (GPT) activities significantly increased with protein levels >275 g kg,1 diet. Based on the broken-line model, the dietary protein requirement for PWG of Jian carp (16.7,55.0 g) was estimated to be 341 g kg,1 diet with a digestible energy of 14.4 MJ kg,1 diet. [source] Comparison of continuous and batch feeding systems on maturation, biochemical composition and immune variables of the oyster Crassostrea corteziensis (Hertlein 1951)AQUACULTURE RESEARCH, Issue 4 2009Miguel A Hurtado Abstract Two feeding systems for maturing oysters were compared, one a continuous feeding system and the other a batch system in which the whole microalgal ration was supplied once daily. The maturation diet consisted in Isochrysis galbana (T-ISO) complemented with an enriched lipid emulsion. Survival and growth did not differ between the feeding systems after 3 weeks of conditioning. Maturation, biochemical composition, fatty acids in membranes and reserves, digestive enzymes activities and immune parameters in Crassostrea corteziensis were analysed. Only oysters fed using the once-daily system had vitellogenic oocytes, whereas the gonad of oysters fed using a continuous-drip system remained immature. Total and differential haemocyte counts were similar between both the systems, but respiratory burst was significantly higher in oysters fed using the once-daily system. Amylase, lipase and trypsin activities in oyster's digestive gland were similar between both the feeding systems. Total lipids, however, differed significantly in oyster tissue in relation to feeding system, with highest level in those fed using the once-daily system, but fatty acid composition in reserves and membrane were similar. No differences were found for biochemical parameters in haemolymph. These results suggest that feeding oysters using a batch, once-daily system allows more rapid initial gonad maturation without affecting general physiological condition and growth. [source] Purification and Characterization of Thermostable ,-Amylase from a Newly Isolated Thermophilic Bacillus stearothermophilus GRE 1ASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 5-6 2005S.M. Zakir Hossain A thermophilic bacterium, Bacillus stearothermophilus GRE 1, isolated from an Ethiopian hyperthermal spring produced a thermostable ,-amylase. Enzyme production in shake flask experiments while using optimum nutrient supplements and environmental conditions was 2.35 U/ml. Under optimized conditions in a bioreactor, 5-6 fold higher enzyme activity was obtained than that of a shake flask. Gel filtration chromatography yielded a purification factor of 33.62-fold and a recovery of 46.52%. The optimum temperature for activity was determined to be 60-70d,C and optimum pH was in the range of 5.5-6.0. The enzyme maintained 50% of its original activity after 45 minutes of incubation at 80d,C, and is stable at pH values of 5.0-9.0. Enzyme activity was strongly inhibited by Cu2+, Zn2+ and Fe2+. The enzyme is calcium independent and 94% and 86% relative activities were displayed with low concentrations of Co2+ and Mg2+, respectively. [source] Use of Co-Immobilized ,-Amylase and Pullulanase in Reduction of Saccharification Time of Starch and Increase in Maltose YieldBIOTECHNOLOGY PROGRESS, Issue 3 2003K. S. Atia ,-Amylase and pullulanase were co-immobilized to poly(acrylamide-acrylic acid) resin [P(AAm-AAc)] using 1-ethyl-3,(3-dimethylaminopropyl) carbodimide hydrochloride (EDC). The combined ,-amylase and pullulanase activity was 32% relative to the nonimmobilized ,-amylase. Co-immobilization of ,-amylase and pullulanase increased the maltose yield compared to thart of the immobilized ,-amylase alone and reduced the saccharification time to about 50 h. The results showed that there is a significant increase in the thermal stability, pH stability, and stability toward , irradiation. The results also suggest that the co-immobilization of ,-amylase and pullulanase is a potentially useful approach for commercial starch hydrolysis. [source] The importance of starch and sucrose digestion in nutritive biology of synanthropic acaridid mites: ,-Amylases and ,-glucosidases are suitable targets for inhibitor-based strategies of mite control,ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY (ELECTRONIC), Issue 3 2009Tomas Erban Abstract The adaptation of nine species of mites that infest stored products for starch utilization was tested by (1) enzymatic analysis using feces and whole mite extracts, (2) biotests, and (3) inhibition experiments. Acarus siro, Aleuroglyphus ovatus, and Tyroborus lini were associated with the starch-type substrates and maltose, with higher enzymatic activities observed in whole mite extracts. Lepidoglyphus destructor was associated with the same substrates but had higher activities in feces. Dermatophagoides farinae, Chortoglyphus arcuatus, and Caloglyphus redickorzevi were associated with sucrose. Tyrophagus putrescentiae and Carpoglyphus lactis had low or intermediate enzymatic activity on the tested substrates. Biotests on starch additive diets showed accelerated growth of species associated with the starch-type substrates. The inhibitor acarbose suppressed starch hydrolysis and growth of the mites. We suggest that the species with higher starch hydrolytic activity in feces were more tolerant to acarbose, and ,-amylase and ,-glucosidase of synanthropic mites are suitable targets for inhibitor-based strategies of mite control. © 2009 Wiley Periodicals, Inc. [source] Macroaffinity Ligand-Facilitated Three-Phase Partitioning (MLFTPP) of ,-Amylases Using a Modified AlginateBIOTECHNOLOGY PROGRESS, Issue 2 2003Kalyani Mondal The crude extracts of ,-amylases when mixed with alginate, tert -butyl alcohol, and ammonium sulfate resulted in an interfacial precipitate containing polymer-bound amylase. The precipitate was dissolved in 1 M maltose to recover ,-amylase activity. The recovery of ,-amylases were 74%, 77%, and 92% in the case of Bacillus amyloliquefaciens, wheat germ, and porcine pancreas, respectively. All purified preparations showed a single band on SDS-PAGE. [source] The role of free fatty acids, pancreatic lipase and Ca2+ signalling in injury of isolated acinar cells and pancreatitis model in lipoprotein lipase-deficient miceACTA PHYSIOLOGICA, Issue 1 2009F. Yang Abstract Aim and methods:, Recurrent pancreatitis is a common complication of severe hypertriglyceridaemia (HTG) often seen in patients carrying various gene mutations in lipoprotein lipase (LPL). This study investigates a possible pathogenic mechanism of cell damage in isolated mouse pancreatic acinar cells and of pancreatitis in LPL-deficient and in wild type mice. Results:, Addition of free fatty acids (FFA) or of chylomicrons to isolated pancreatic acinar cells caused stimulation of amylase release, and at higher concentrations it also caused cell damage. This effect was decreased in the presence of the lipase inhibitor orlistat. Surprisingly, pancreatic lipase whether in its active or inactive state could act like an agonist by inducing amylase secretion, increasing cellular cGMP levels and converting cell damaging sustained elevations of [Ca2+]cyt to normal Ca2+ oscillations. Caerulein increases the levels of serum amylase and caused more severe inflammation in the pancreas of LPL-deficient mice than in wild type mice. Conclusion:, We conclude that high concentrations of FFA as present in the plasma of LPL-deficient mice and in patients with HTG lead to pancreatic cell damage and are high risk factors for the development of acute pancreatitis. In addition to its enzymatic effect which leads to the generation of cell-damaging FFA from triglycerides, pancreatic lipase also prevents Ca2+ overload in pancreatic acinar cells and, therefore, counteracts cell injury. [source] Production of ,-Amylase and Glucoamylase by a New Isolate of Trichoderma sp.ENGINEERING IN LIFE SCIENCES (ELECTRONIC), Issue 4 2004Using Sorghum Starch as a Carbon Source The performance of a new Trichoderma sp. isolate to produce extracellular ,-amylase and glucoamylase from raw sorghum starch was evalutated. To reduce the costs of starch saccharification and the consumption of amylolytic enzymes, this microorganism has been used for the first time in cultivations using such a carbon source without any prior gelatinization. [source] A multivariate biomarker-based model predicting population-level responses of Daphnia magnaENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 9 2003Wim M. De Coen Abstract A multivariate model is proposed relating short-term biomarker measurements in Daphnia magna to chronic effects (21-d exposure) occurring at the population level (time to death, mean brood size, mean total young per female, intrinsic rate of natural increase, net reproductive rate, and growth). The results of the short-term exposure (48h-96 h) to eight model toxicants (cadmium, chromium, mercury, tributyl tin, linear alkylsulfonic acid, sodium pentachlorophenolate, lindane, and 2,4-dichloro-phenoxyacetic acid) on the following biomarkers were used for the multivariate model: digestive enzymes (amylase, cellulase, ,-galactosidase, trypsin, and esterase), enzymes of the intermediary metabolism (glycogen phosphorylase, glucose-6-phosphate de-hydrogenase, pyruvate kinase, lactate dehydrogenase, and isocitrate dehydrogenase), cellular energy allocation (CEA) (protein, carbohydrate, and lipid content and electron transport activity), and DNA damage and antioxidative stress activity. Using partial least squares to latent structures (PLS), a two-component model was obtained with R2 of 0.68 and a Q2 value of 0.60 based on the combined analysis of a limited number of the 48- and 96-h biomarker responses. For the individual population-level responses, the R2 values varied from 0.66 to 0.77 and the Q2 values from 0.52 to 0.69. Energy-related biomarkers (cellular energy allocation, lipid contents, anaerobic metabolic activity,pyruvate kinase, and lactate dehydrogenase), combined with parameters related to oxidative stress (catalase) and DNA damage measured after 48 and 96 h of exposure, were able to predict long-term effects at higher levels of biological organization. [source] Exocrine pancreatic dysfunction in sepsisEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 3 2003B. Tribl Abstract Background Sepsis in critical illness is associated with the progressive failure of multiple organs. This study aims to establish a correlation between the severity of sepsis and exocrine pancreatic dysfunction. Materials and methods In a prospective cohort study pancreatic exocrine function was tested by means of a secretin-cholecystokinin test in 21 critically ill, mechanically ventilated patients with sepsis according to criteria of the American College of Chest Physicians/Society of Critical Care Medicine Consensus Conference Committee (ACCP/SCCM): 11 patients with shock and 10 patients without shock. Data were compared with seven healthy controls. Results The volume of duodenal fluid was not statistically different in the three groups. Sepsis patients without shock had significantly reduced content of amylase and chymotrypsin in duodenal juice compared with healthy controls (P < 0·01). Secretion of amylase, chymotrypsin, trypsin (P < 0·01 each) and bicarbonate in duodenal fluid (P < 0·05) was impaired in the septic shock patients when compared with the healthy controls. The content of trypsin was different between sepsis patients and septic shock patients (P < 0·05). Spearman correlation analysis was significant between the amylase secretion and the APACHE III and SOFA scores (P < 0·01). The SOFA score was also related to secretion of trypsin (P < 0·05). In patients on pressor therapy, use of norepinephrine was associated with a significant decrease in bicarbonate secretion (P < 0·05). Conclusions Sepsis is associated with secretory pancreatic dysfunction that is worse in septic shock than in sepsis without shock. Impaired exocrine function was significantly correlated to the APACHE III and SOFA scores. [source] Enzymes in the acquired enamel pellicleEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 1 2005Christian Hannig The acquired pellicle is a biofilm, free of bacteria, covering oral hard and soft tissues. It is composed of mucins, glycoproteins and proteins, among which are several enzymes. This review summarizes the present state of research on enzymes and their functions in the dental pellicle. Theoretically, all enzymes present in the oral cavity could be incorporated into the pellicle, but apparently enzymes are adsorbed selectively onto dental surfaces. There is clear evidence that enzymes are structural elements of the pellicle. Thereby they exhibit antibacterial properties but also facilitate bacterial colonization of dental hard tissues. Moreover, the immobilized enzymes are involved in modification and in homeostasis of the salivary pellicle. It has been demonstrated that amylase, lysozyme, carbonic anhydrases, glucosyltransferases and fructosyltransferase are immobilized in an active conformation in the pellicle layer formed in vivo. Other enzymes, such as peroxidase or transglutaminase, have been investigated in experimental pellicles. Despite the depicted impact of enzymes on the formation and function of pellicle, broader knowledge on their properties in the in vivo -formed pellicle is required. This might be beneficial in the development of new preventive and diagnostic strategies. [source] Inhibition of Rac1 decreases the severity of pancreatitis and pancreatitis-associated lung injury in miceEXPERIMENTAL PHYSIOLOGY, Issue 10 2008Marcelo G. Binker Pancreatitis is a disease with high morbidity and mortality. In vitro experiments on pancreatic acini showed that supramaximal but not submaximal cholecystokinin (CCK) stimulation induces effects in the acinar cell that can be correlated with acinar morphological changes observed in the in vivo experimental model of cerulein-induced pancreatitis. The GTPase Rac1 was previously reported to be involved in CCK-evoked amylase release from pancreatic acinar cells. Here, we demonstrate that pretreatment with the Rac1 inhibitor NSC23766 (100 ,m, 2 h) effectively blocked Rac1 translocation and activation in CCK-stimulated pancreatic acini, without affecting activation of its closely related GTPase, RhoA. This specific Rac1 inhibition decreased supramaximal (10 nM) CCK-stimulated acinar amylase release (27.% reduction), which seems to be connected to the reduction observed in serum amylase (46.6% reduction) and lipase levels (46.1% reduction) from cerulein-treated mice receiving NSC23766 (100 nmol h,1). The lack of Rac1 activation also reduced formation of reactive oxygen species (ROS; 20.8% reduction) and lactate dehydrogenase release (LDH; 24.3% reduction), but did not alter calcium signaling or trypsinogen activation in 10 nM CCK-stimulated acini. In the in vivo model, the cerulein-treated mice receiving NSC23766 also presented a decrease in both pancreatic and lung histopathological scores (reduction in oedema, 32.4 and 66.4%; haemorrhage, 48.3 and 60.2%; and leukocyte infiltrate, 53.5 and 43.6%, respectively; reduction in pancreatic necrosis, 65.6%) and inflammatory parameters [reduction in myeloperoxidase, 52.2 and 38.9%; nuclear factor ,B (p65), 61.3 and 48.6%; and nuclear factor ,B (p50), 46.9 and 44.9%, respectively], together with lower serum levels for inflammatory (TNF-,, 40.4% reduction) and cellular damage metabolites (LDH, 52.7% reduction). Collectively, these results suggest that pharmacological Rac1 inhibition ameliorates the severity of pancreatitis and pancreatitis-associated lung injury through the reduction of pancreatic acinar damage induced by pathological digestive enzyme secretion and overproduction of ROS. [source] Inhibition of recombinant human maltase glucoamylase by salacinol and derivativesFEBS JOURNAL, Issue 12 2006Elena J. Rossi Inhibitors targeting pancreatic ,-amylase and intestinal ,-glucosidases delay glucose production following digestion and are currently used in the treatment of Type II diabetes. Maltase-glucoamylase (MGA), a family 31 glycoside hydrolase, is an ,-glucosidase anchored in the membrane of small intestinal epithelial cells responsible for the final step of mammalian starch digestion leading to the release of glucose. This paper reports the production and purification of active human recombinant MGA amino terminal catalytic domain (MGAnt) from two different eukaryotic cell culture systems. MGAnt overexpressed in Drosophila cells was of quality and quantity suitable for kinetic and inhibition studies as well as future structural studies. Inhibition of MGAnt was tested with a group of prospective ,-glucosidase inhibitors modeled after salacinol, a naturally occurring ,-glucosidase inhibitor, and acarbose, a currently prescribed antidiabetic agent. Four synthetic inhibitors that bind and inhibit MGAnt activity better than acarbose, and at comparable levels to salacinol, were found. The inhibitors are derivatives of salacinol that contain either a selenium atom in place of sulfur in the five-membered ring, or a longer polyhydroxylated, sulfated chain than salacinol. Six-membered ring derivatives of salacinol and compounds modeled after miglitol were much less effective as MGAnt inhibitors. These results provide information on the inhibitory profile of MGAnt that will guide the development of new compounds having antidiabetic activity. [source] Relation between domain evolution, specificity, and taxonomy of the ,-amylase family members containing a C-terminal starch-binding domainFEBS JOURNAL, Issue 4 2003tefan Jane The ,-amylase family (glycoside hydrolase family 13; GH 13) contains enzymes with approximately 30 specificities. Six types of enzyme from the family can possess a C-terminal starch-binding domain (SBD): ,-amylase, maltotetraohydrolase, maltopentaohydrolase, maltogenic ,-amylase, acarviose transferase, and cyclodextrin glucanotransferase (CGTase). Such enzymes are multidomain proteins and those that contain an SBD consist of four or five domains, the former enzymes being mainly hydrolases and the latter mainly transglycosidases. The individual domains are labelled A [the catalytic (,/,)8 -barrel], B, C, D and E (SBD), but D is lacking from the four-domain enzymes. Evolutionary trees were constructed for domains A, B, C and E and compared with the ,complete-sequence tree'. The trees for domains A and B and the complete-sequence tree were very similar and contain two main groups of enzymes, an amylase group and a CGTase group. The tree for domain C changed substantially, the separation between the amylase and CGTase groups being shortened, and a new border line being suggested to include the Klebsiella and Nostoc CGTases (both four-domain proteins) with the four-domain amylases. In the ,SBD tree' the border between hydrolases (mainly,-amylases) and transglycosidases (principally CGTases) was not readily defined, because maltogenic ,-amylase, acarviose transferase, and the archaeal CGTase clustered together at a distance from the main CGTase cluster. Moreover the four-domain CGTases were rooted in the amylase group, reflecting sequence relationships for the SBD. It appears that with respect to the SBD, evolution in GH 13 shows a transition in the segment of the proteins C-terminal to the catalytic (,/,)8 -barrel(domain A). [source] Involvement of Gln937 of Streptococcus downei GTF-I glucansucrase in transition-state stabilizationFEBS JOURNAL, Issue 13 2000Vincent Monchois Multiple alignment of deduced amino-acid sequences of glucansucrases (glucosyltransferases and dextransucrases) from oral streptococci and Leuconostoc mesenteroides has shown them to share a well-conserved catalytic domain. A portion of this domain displays homology to members of the ,-amylase family (glycoside hydrolase family 13), which all have a (,/,)8 barrel structure. In the glucansucrases, however, the ,-helix and ,-strand elements are circularly permuted with respect to the order in family 13. Previous work has shown that amino-acid residues contributing to the active site of glucansucrases are situated in structural elements that align with those of family 13. In ,-amylase and cyclodextrin glucanotransferase, a histidine residue has been identified that acts to stabilize the transition state, and a histidine is conserved at the corresponding position in all other members of family 13. In all the glucansucrases, however, the aligned position is occupied by glutamine. Mutants of glucosyltransferase I were constructed in which this glutamine, Gln937, was changed to histidine, glutamic acid, aspartic acid, asparagine or alanine. The effects on specific activity, ability to form glucan and ability to transfer glucose to a maltose acceptor were examined. Only histidine could substitute for glutamine and maintain Michaelis,Menten kinetics, albeit at a greatly reduced kcat, showing that Gln937 plays a functionally equivalent role to the histidine in family 13. This provides additional evidence in support of the proposed alignment of the (,/,)8 barrel structures. Mutation at position 937 altered the acceptor reaction with maltose, and resulted in the synthesis of novel gluco-oligosaccharides in which ,1,3-linked glucosyl units are joined sequentially to maltose. [source] Preparation of phosphorus and carbohydrate microcapsules for manipulating dietary C : P ratio for aquatic suspension-feedersFRESHWATER BIOLOGY, Issue 2 2003Daniel A. Kreeger SUMMARY 1.,Dietary phosphorus can be limiting for aquatic animals such as suspension-feeders. However, our understanding has been limited by the difficulty of manipulating dietary P without altering other aspects of food quality. We microencapsulated various forms of bioavailable P with carbohydrate to manipulate dietary C : P ratio for suspension-feeders. 2.,Calcium phosphate, sodium hexametaphosphate, sodium tripolyphosphate and tetrasodium pyrophosphate were each mixed with a concentrated solution of a carbohydrate base (either maltodextrin or potato starch) and microencapsulated using an interfacial polymerisation technique. Each of the 10 types of capsules produced had a particle size ideal for suspension-feeders (3,10 ,m). 3.,Leakage rates were low (<12% of capsule weight per day). Relative enzymatic breakdown in vitro by carbohydrases (amylase or cellulase) was similar among the 10 capsule types and was always at least 15 times the comparable leakage rate. 4.,Release of dissolved P from enzyme-treated capsules varied depending on capsule P content. Liberation of P from capsules prepared from 20% w/w sodium hexametaphosphate in maltodextrin (molar C : P = 1.8) was three times greater than all other types, and this combination appears most suitable as a dietary supplement for zooplankton. 5.,Although P content and capsule integrity were greatly influenced by choice of carbohydrate, choice of P compound, and the mixing ratio of the two, P-rich artificial microparticles can be produced that have low leakiness, high digestibility, and a physical size suitable for aquatic suspension-feeders. Therefore, microcapsules represent promising tools for manipulating dietary C : P for suspension feeders. [source] Plasticity in the adult rat pancreas: Transdifferentiation of exocrine to hepatocyte-like cells in primary cultureHEPATOLOGY, Issue 6 2004Jessy Lardon Under certain experimental conditions, hepatocytes can arise in the pancreas. It has been suggested that the pancreas retains a source of hepatocyte progenitor cells. However, such cells have not been yet identified in the adult pancreas. We describe here the transdifferentiation of primary rat pancreatic exocrine cells into hepatocyte-like cells during 5 days of tissue culture in the presence of dexamethasone (DX). Using reverse-transcription polymerase chain reaction and immunocytochemistry, it was observed that DX treatment induced albumin RNA and protein expression in the cells. Coexpression of albumin and amylase, and the absence of cell proliferation, demonstrated a direct transdifferentiation of acinar cells to hepatocytic cells. CCAAT enhancer-binding protein-ß protein, a liver-enriched transcription factor that is considered to be the master switch in pancreatohepatic transdifferentiation, and ,-fetoprotein were markedly upregulated in the cells after treatment with DX. We compared transcriptional profiles of freshly isolated exocrine cells and DX-treated cells using oligonucleotide microarrays and found that multiple liver-specific genes are induced along with albumin, and that certain pancreatic genes are downregulated in the DX-treated cells. In conclusion, these observations support the notion of plasticity in the adult pancreas and that exocrine cells can be reprogrammed to transdifferentiate into other cell types such as hepatocytes. (HEPATOLOGY 2004;39:1499,1507.) [source] Use of activated protein C has no avail in the early phase of acute pancreatitisHPB, Issue 6 2008Sinan Akay Abstract Objectives. Sepsis and acute pancreatitis have similar pathogenetic mechanisms that have been implicated in the progression of multiple organ failure. Drotrecogin alfa, an analogue of endogenous protein C, reduces mortality in clinical sepsis. Our objective was to evaluate the early therapeutic effects of activated protein C (APC) in a rat model of acute necrotizing pancreatitis. Subjects and method. Acute necrotizing pancreatitis was induced by intraductal injection of 5% Na taurocholate. Hourly bolus injections of saline or recombinant human APC (drotrecogin alfa) was commenced via femoral venous catheter four hours after the induction of acute pancreatitis. The experiment was terminated nine hours after pancratitis induction. Animals in group one (n=20) had a sham operation while animals in group two (n=20) received saline and animals in group three (n=20) received drotrecogin alfa boluses after acute pancreatitis induction. Pancreatic tissue for histopathologic scores and myeloperoxidase, glutathione reductase, glutathione peroxidase, and catalase activites were collected, and blood for serum amylase, urea, creatinine, and inleukin-6 measurements was withdrawn. Results. Serum amylase activity was significantly lower in the APC treated group than the untreated group (17,435±432 U/L vs. 27,426±118 U/L, respectively). While the serum interleukin-6 concentration in the APC untreated group was significantly lower than the treated group (970±323 pg/mL vs. 330±368 pg/mL, respectively). Conclusion. In the early phase of acute pancreatitis, drotrecogin alfa treatment did not result in a significant improvement in oxidative and inflammatory parameters or renal functions. [source] Exercise-induced cholangitis and pancreatitisHPB, Issue 2 2005JOHN G. TOUZIOS Abstract Background. Cholangitis requires bactibilia and increased biliary pressure. Pancreatitis may be initiated by elevated intraductal pressure. The sphincter of Oddi regulates pancreatobiliary pressures and prevents reflux of duodenal contents. However, following biliary bypass or pancreatoduodenectomy, increased intra-abdominal pressure may be transmitted into the bile ducts and/or pancreas. The aim of this analysis is to document that cholangitis or pancreatitis may be exercise-induced. Methods. The records of patients with one or more episodes of cholangitis or pancreatitis precipitated by exercise and documented to have patent hepatico- or pancreatojejunostomies were reviewed. Cholangitis was defined as fever with or without abdominal pain and transiently abnormal liver tests. Pancreatitis was defined as abdominal pain, with transient elevation of serum amylase and documented by peripancreatic inflammation on computerized tomography. Results. Twelve episodes of cholangitis occurred in six patients who had undergone hepaticojejunostomy for biliary stricture (N=3), Type I choledochal cyst (N=2), or pancreatoduodenectomy for renal cell carcinoma metastatic to the pancreas (N=1). Four episodes of pancreatitis occurred in two patients who had undergone pancreatoduodenectomy for ampullary carcinoma or chronic pancreatitis. Workup and subsequent follow-up for a median of 21 months have not documented anastomotic stricture. Each episode of cholangitis and pancreatitis was brought on by heavy exercise and avoidance of this level of exercise has prevented future episodes. Conclusion. Following biliary bypass or pancreatoduodenectomy, significant exercise may increase intra-abdominal pressure and cause cholangitis or pancreatitis. Awareness of this entity and behavior modification will avoid unnecessary procedures in these patients. [source] | |||||||||||||||||||||||||||||||||||||