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Trypsin Activity (trypsin + activity)
Selected AbstractsControl of the release of digestive enzymes in the larvae of the fall armyworm, Spodoptera frugiperdaARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY (ELECTRONIC), Issue 1 2010Digali Lwalaba Abstract There is a basal level of enzyme activity for trypsin, aminopeptidase, amylase, and lipase in the gut of unfed larval (L6) Spodoptera frugiperda. Trypsin activity does not decrease with non-feeding, possibly because of the low protein levels in plants along with high amino acid requirements for growth and storage (for later reproduction in adults). Therefore, trypsin must always be present so that only a minimal protein loss via egestion occurs. Larvae, however, adjust amylase activity to carbohydrate ingestion, and indeed amylase activity is five-fold higher in fed larvae compared to unfed larvae. Gut lipase activity is low, typical of insects with a high carbohydrate diet. A flat-sheet preparation of the ventriculus was used to measure the release of enzymes in response to specific nutrients and known brain/gut hormones in S. frugiperda. Sugars greatly increase (>300%) amylase release, but starch has no effect. Proteins and amino acids have little or no effect on trypsin or aminopeptidase release. The control of enzyme release in response to food is likely mediated through neurohormones. Indeed, an allatostatin (Spofr-AS A5) inhibits amylase and trypsin, and allatotropin (Manse- AT) stimulates amylase and trypsin release. Spofr-AS A5 also inhibits ileum myoactivity and Manse-AT stimulates myoactivity. The epithelial secretion rate of amylase and trypsin was about 20% of the amount of enzyme present in the ventricular lumen, which, considering the efficient counter-current recycling of enzymes, suggests that the secretion rate is adequate to replace egested enzymes. © 2009 Wiley Periodicals, Inc. [source] Effects of dietary lipid levels on the growth, digestive enzyme, feed utilization and fatty acid composition of Japanese sea bass (Lateolabrax japonicus L.) reared in freshwaterAQUACULTURE RESEARCH, Issue 2 2010Gang Luo Abstract Triplicate groups of 40 Japanese sea bass Lateolabrax japonicus reared in freshwater (average weight, 9.52±0.47 g) were fed with six isonitrogenous (,46% crude protein) diets containing 6%, 8%, 10%, 12%, 14% or 16% lipid for 10 weeks respectively. The results showed that the maximum weight gain (WG), specific growth rate (SGR), feed intake (FI) and protein efficiency ratio (PER) all occurred at the 10% lipid level (P<0.05) and growth depression occurred when the dietary lipid level was over 12%. Whole body and liver lipid concentrations were enhanced with the increase in the dietary lipid levels, but the muscle lipid content did not significantly change with the increase in the dietary lipid levels. Both liver pepsin and trypsin activities increased with dietary lipid levels ranging from 6% to 10%, and then decreased with a further increase in the dietary lipid content. Liver lipase activities showed a positive correlation with dietary lipid levels, but amylase activities were not markedly influenced by dietary lipid levels. High proportions of 18:1n-9, 20:1n-9, eicosapentaenoic acid (20:5n-3; EPA), 22:1n-11 and docosahexaenoic acid (22:6n-3; DHA), and low concentrations of n-6 fatty acids, particularly 18:2n-6 occurring in the liver and muscle, to some extent, reflected the fatty acid composition in experimental diets. [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] Cover Picture: Electrophoresis 14'2010ELECTROPHORESIS, Issue 14 2010Article first published online: 21 JUL 2010 Issue no. 14 is a "mini special issue" on "Microscale Separation Methods for Metabolomics" comprising 9 manuscripts on metabolomics and 12 manuscripts on various topics in nucleic acids, biomarkers, proteomics, miniaturization, etc. Part I has 9 manuscripts on metabolomics featuring new technological developments and the potential of CE-MS, targeted analysis of one class of metabolites and non-targeted analysis, and data interpretation that is essential to acquire useful biological information. In short, the importance of CE and, generally, of microscale separation methods for metabolomics is rapidly increasing and the papers published in this issue give an overview of this field. Part II has 2 research papers on biomarkers while Part III is on various aspects of nucleic acids including but not limited to genotyping, PCR, SSCP, PCR and detection of DNA. Part IV describes various aspects of fundamentals and methodology in microfluidics, cell lysates by 2-DE, CE-LIF of plasmid DNA, whole blood assay of trypsin activity, etc. [source] Characterization of the sgtR1 and sgtR2 genes and their role in regulating expression of the sprT gene encoding Streptomyces griseus trypsinFEMS MICROBIOLOGY LETTERS, Issue 1 2007Eun A Oh Abstract The sgtR1 and sgtR2 genes encoding putative regulators similar to the Aha1 and ArsR families, respectively, were identified downstream from the sprT gene. To investigate their function, expression vectors containing various combinations of sprT, sgtR1, and sgtR2 were transformed into Streptomyces lividans and Streptomyces griseus. The trypsin activity levels produced by S. lividans harboring pWHM3-TR2 (sprT and sgtR2) or pWHM3-TR1R2 (sprT, sgtR2, and sgtR2) were, respectively, 6.6 or 8.9 times that of S. lividans transformed with pWHM3-T (sprT). In the pWHM3-TR1R2 transformant, the transcription of sprT consistently occurred during the earlier stages of growth and was maintained at a higher level throughout the 6 days of cultivation. Streptomyces griseus IFO13350 harboring pWHM3-TR1R2 also produced trypsin activity 2.1 times that of the pWHM3-T transformant. However, all S. griseus,adpA transformants produced lower SGT activity than the wild-type strain, and none could overcome the deficiency in AdpA transcriptional activator, suggesting that AdpA is an absolute prerequisite for sprT expression. The sprT transcript was detected at a high level only in the wild-type strain, but the sgtR1 and sgtR2 transcript levels were very similar between the S. griseus IFO13350 and ,adpA strains. This clearly demonstrates that the transcription of the sgtR1 and sgtR2 genes is not dependent on AdpA and that they are therefore not members of the AdpA regulon. [source] Effects of ,-glucanase and xylanase supplementation on gastrointestinal digestive enzyme activities of weaned piglets fed a barley-based dietJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 2 2009C. L. Fan Summary The effects of supplementing a barley-based diet for weaned piglets with exogenous ,-glucanase and xylanase on gastrointestinal digestive enzyme activities were investigated. Thirty-six cross-bred weaned piglets were randomly assigned to two groups with three pens based on sex and mass. Each group was fed on the diet based on barley with or without added ,-glucanase and xylanase (0.15%) for a 4-week period. The results showed that enzyme supplementation improved growth performance of piglets significantly (p < 0.05), but had no effect (p = 0.091) on average daily feed intake. The results also showed that supplementation of ,-glucanase and xylanase had no effect on pepsin activity in gastric contents but slightly decreased (p = 0.092) the pepsin activity in gastric mucosa. Meanwhile, no effect of enzyme supplementation on trypsin activity in duodenal contents was observed. However, the activities of amylase and lipase in duodenal contents were significantly (p < 0.05) decreased, whereas the activities of maltase, sucrase and ,-glutamyl transpeptidase (,-GT) in jejunal and ileal mucosa were enhanced significantly (p < 0.05). The improvement of disaccharidase and ,-GT activity may be attributed to the positive impacts of exogenous enzymes on digestion and absorption of the nutrients. In conclusion, the current results indicated that supplementation with enzymes in barley-based diets could improve the growth performance of piglets, decrease the activities of amylase and lipase in duodenal contents and increase the activities of disaccharidase and ,-GT in jejunal and ileal mucosa. [source] Effects of tea polyphenols on the activities of soybean trypsin inhibitors and trypsinJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 2 2004Huihua Huang Abstract Tea polyphenols (TPs) and other materials were extracted from Chinese green tea, and their effects on trypsin inhibitors and trypsin were analysed. TPs were found to have a deactivation effect on both Kunitz trypsin inhibitor (KTI) and Bowman,Birk trypsin inhibitor (BBTI). KTI was more easily deactivated than BBTI by complexing with TPs. The deactivation effect of TPs on KTI and BBTI reached a maximum at a TP/KTI ratio of 25 and a TP/BBTI ratio of 16. However, the deactivation effect of TPs on KTI and BBTI was reduced dramatically when KTI and BBTI were already complexed with trypsin. TPs were also found to inhibit trypsin. The inhibitory activity of TPs, KTI and BBTI on trypsin was found to decrease in the order BBTI > gtTI > gtPs. Complete inhibition of trypsin by TPs could not be achieved. When the TP concentration was increased to about 17 µg ml,1, the residual activity of trypsin was maintained at 400 TU mg,1, equivalent to 32% of the initial trypsin activity. In TP inhibition the KM value for trypsin remained unchanged at 5.88 × 10,4 mol l,1 and Vmax decreased when benzoyl- DL -arginine- p -nitroanilide (BAPNA) was used as substrate. The pattern of trypsin inhibition by TPs is non-competitive. Copyright © 2004 Society of Chemical Industry [source] Response of intestinal proteinase activities to the feeding of isolated winged bean (Psophocarpus tetragonolobus) and soya bean (Glycine max) trypsin inhibitors in ratsJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 11 2001Naoki Nishino Abstract The antinutritional activities of trypsin inhibitors (TIs) were compared between winged beans (Psophocarpus tetragonolobus) and soya beans (Glycine max). The inhibitors of the two beans were isolated by trypsin-bound Sepharose 4B, and 50,mg of lyophilised powders were intubated intragastrically into 24,h fasted rats. The activities of trypsin and chymotrypsin were compared after 30, 60 and 180,min in the washings of the upper, middle and lower parts of the small intestine. The elution profiles of TI and non-TI compounds in the affinity chromatography were similar in the two beans, and the antitryptic activities were concentrated 5.5 and 6.2 times (based on specific activity) for winged beans and soya beans respectively. Regardless of the TI fed to rats, trypsin activity in the upper intestine was suppressed to almost undetectable levels at 30 and 60,min after intubation. The activities in the middle and lower intestines were also substantially lowered when rats were fed winged bean TI, and significant differences were detected at 30 and 60,min after intubation when compared with rats fed soya bean TI. However, at 180,min after feeding, no differences were found in the trypsin activity in any gut segments. Similar inhibitory properties of isolated TIs were observed in chymotrypsin activities in the small intestine. The results suggest that winged bean TI may have greater inhibitory activity on the intestinal proteinase compared with soya bean TI. © 2001 Society of Chemical Industry [source] Highly stable trypsin-aggregate coatings on polymer nanofibers for repeated protein digestionPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 7 2009Byoung Chan Kim Abstract A stable and robust trypsin-based biocatalytic system was developed and demonstrated for proteomic applications. The system utilizes polymer nanofibers coated with trypsin aggregates for immobilized protease digestions. After covalently attaching an initial layer of trypsin to the polymer nanofibers, highly concentrated trypsin molecules are crosslinked to the layered trypsin by way of a glutaraldehyde treatment. This process produced a 300-fold increase in trypsin activity compared with a conventional method for covalent trypsin immobilization, and proved to be robust in that it still maintained a high level of activity after a year of repeated recycling. This highly stable form of immobilized trypsin was resistant to autolysis, enabling repeated digestions of BSA over 40,days and successful peptide identification by LC-MS/MS. This active and stable form of immobilized trypsin was successfully employed in the digestion of yeast proteome extract with high reproducibility and within shorter time than conventional protein digestion using solution phase trypsin. Finally, the immobilized trypsin was resistant to proteolysis when exposed to other enzymes (i.e., chymotrypsin), which makes it suitable for use in "real-world" proteomic applications. Overall, the biocatalytic nanofibers with trypsin aggregate coatings proved to be an effective approach for repeated and automated protein digestion in proteomic analyses. [source] Modified Two-Layer Preservation Method (M-Kyoto/PFC) Improves Islet Yields in Islet IsolationAMERICAN JOURNAL OF TRANSPLANTATION, Issue 3 2006H. Noguchi Islet allotransplantation can achieve insulin independence in patients with type I diabetes. Recent reports show that the two-layer method (TLM), which employs oxygenated perfluorochemical (PFC) and UW solution, is superior to simple cold storage in UW for pancreas preservation in islet transplantation. However, UW solution has several disadvantages, including the inhibition of Liberase activity. In this study, we investigated the features of a new solution, designated M-Kyoto solution. M-Kyoto solution contains trehalose and ulinastatin as distinct components. Trehalose has a cytoprotective effect against stress, and ulinastatin inhibits trypsin. In porcine islet isolation, islet yield was significantly higher in the M-Kyoto/PFC group compared with the UW/PFC group. There was no significant difference in ATP content in the pancreas between the two groups, suggesting that different islet yields are not due to their differences as energy sources. Compared with UW solution, M-Kyoto solution significantly inhibited trypsin activity in the digestion step; moreover, M-Kyoto solution inhibited collagenase digestion less than UW solution. In conclusion, the advantages of M-Kyoto solution are trypsin inhibition and less collagenase inhibition. Based on these data, we now use M-Kyoto solution for clinical islet transplantation from nonheart-beating donor pancreata. [source] Growth, digestive capacity and intestinal microflora of juvenile Jian carp (Cyprinus carpio var. Jian) fed graded levels of dietary inositolAQUACULTURE RESEARCH, Issue 8 2009Wei-Dan Jiang Abstract A 60-day feeding trial was carried out with juvenile Jian carp (Cyprinus carpio var. Jian) to study the effects of myo -inositol (MI) on the growth, digestive enzyme and intestinal microbial population. Diets with seven levels of inositol (163.5, 232.7, 384.2, 535.8, 687.3, 838.8 and 990.3 mg MI kg,1 diet) were fed to Jian carp (initial weight 22.28±0.07 g). Per cent weight gain (PWG) was improved with increasing inositol levels up to 535.8 mg MI kg,1 diet (P<0.05), and plateaued (P>0.05). The protein production value, lipid production value and ash production value were increased with increasing dietary inositol levels up to 384.2, 838.8 and 838.8 mg MI kg,1 diet respectively (P<0.05). Although intestinal protein content and trypsin activity were not affected by inositol levels (P>0.05), chymotrypsin, lipase and amylase activities in intestine were the lowest for fish fed the MI-unsupplemented diet (P<0.05). Alkaline phosphatase, Na+, K+ -ATPase, ,-glutamyl transpeptidase and creatinkinase activities in the intestine were increased with an increase in the inositol levels up to 384.2,687.3 mg MI kg,1 diet (P<0.05). Intestinal Aeromonas hydrophila and Escherichia coli decreased with an increase in the levels of dietary inositol up to 232.7 and 687.3 mg MI kg,1 diet respectively (P<0.05), while Lactobacillus in the intestine increased with an increase in inositol levels up to 990.3 mg MI kg,1 diet (P<0.05). In conclusion, inositol improved growth, digestive capacity and intestinal microbial population of juvenile Jian carp, and the dietary inositol requirement for PWG of juvenile Jian carp is 518.0 mg MI kg,1 diet. [source] Trypsin enzyme activity during larval development of Litopenaeus vannamei (Boone) fed on live feedsAQUACULTURE RESEARCH, Issue 5 2002A C Puello-Cruz Abstract Larval stages of the Pacific white shrimp, Litopenaeus vannamei (Boone) were fed standard live diets of mixed microalgae from the first to the third protozoea (PZ1 to PZ3), followed by Artemia nauplii until post-larvae 1 (PL1). Trypsin enzyme activity for each larval stage was determined using N -,-p-toluenesulphonyl- l -arginine methyl ester (TAME) as a substrate. Results were expressed as enzyme content to assess ontogenetic changes during larval development. Tissue trypsin content (IU µg,1 DW for each larval stage) was significantly highest at the PZ1 stage and declined through subsequent stages to PL1. This contrasts with previously observed patterns of trypsin development in Litopenaeus setiferus (Linnaeus) and other penaeid genera, which exhibit a peak in trypsin activity at the third protozoea/first mysis (PZ3/M1) larval stage. Litopenaeus vannamei larvae transferred to a diet of Artemia at the beginning of the second protozoea (PZ2) stage were significantly heavier on reaching the first mysis stage (M1) than those fed algae, while survival was not significantly different between treatments. At both PZ2 and PZ3 stages, trypsin content in larvae feeding on Artemia was significantly lower than in those feeding on algae. The rapid decline in trypsin content from PZ1 and the flexible enzyme response from PZ2 suggest that L. vannamei is physiologically adapted to transfer to a more carnivorous diet during the mid-protozoeal stages. [source] Exogenous and endogenous protease inhibitors in the gut of the fall armyworm larvae, Spodoptera frugiperdaARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY (ELECTRONIC), Issue 2 2010Digali Lwalaba Abstract A dose-dependent inhibition of endogenous trypsin and aminopeptidase occurs in the lumen of Spodoptera frugiperda after feeding L6 larvae exogenous inhibitors soybean trypsin inhibitor (SBTI), tosyl-L-lysine chloromethyl ketone-HCl (TLCK), or bestatin, respectively, for 3 days. TLCK inhibits trypsin in tissue extracts and in secretions more strongly than SBTI. The aminopeptidase released into the lumen (containing the peritrophic membrane) is strongly inhibited by bestatin, but the membrane-bound enzyme is not. A bound enzyme may be more resistant to an inhibitor than unbound. A cross-class elevation of aminopeptidase activity occurs in response to ingested trypsin inhibitor, but there was no cross-class effect of aminopeptidase inhibitor (bestatin) on trypsin activity. An endogenous trypsin and aminopeptidase inhibitor is present in the lumen and ventricular cells. The strength of the endogenous trypsin inhibition seems to be in the same range as that resulting from ingestion of the exogenous inhibitor SBTI. In some insect species, considerable trypsin secretion occurs in unfed as well as in fed animals, and endogenous protease inhibitors might function to protect the ventricular epithelium by inactivation of trypsin when less food is available. © 2010 Wiley Periodicals, Inc. [source] Effect of disaccharides on the stabilization of bovine trypsin against detergent and autolysisBIOTECHNOLOGY PROGRESS, Issue 3 2010Shivcharan Prasad Abstract Osmolytes have been reported to stabilize biomolecules and even whole organisms against exposure to adverse environmental conditions. In this work, we report for the first time the use of some of these osmolytes, viz., the disaccharides trehalose and sucrose, in the stabilization of bovine trypsin against exposure to the anionic detergent sodium dodecyl sulfate and autolysis. Exposure of trypsin to SDS at a molar ratio of 1:45 led to decrease in trypsin activity by 61%. In the presence of 1 M sucrose and 1 M trehalose, the residual trypsin activity was found to increase to that of original enzyme activity. These two disaccharides were also found to slow down the rate of autolysis, resulting in residual activities of 80 and 88%, respectively, after incubation for 24 h. Active site titration showed retention of the fraction of active sites in the presence of trehalose. Fluorescence and CD spectroscopies were used to decipher the probable mechanism of this protective role of the disaccharides. Although complete resumption of secondary structure was not seen in the presence of the two disaccharides, the spectra of trypsin in the presence of stabilizers resembled the spectrum of native trypsin and were significantly different from the spectrum of detergent-denatured enzyme. Correlating the data obtained from spectroscopy with those obtained from activity assay, we propose that the retention of secondary structure of the enzyme is largely responsible for the retention of the functionally active form of trypsin. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2010 [source] | |||||||||||||