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Bioactive Peptides (bioactive + peptide)
Selected AbstractsDip-Pen Nanolithography of Bioactive Peptides on Collagen-Terminated Retinal Membrane,ADVANCED MATERIALS, Issue 19 2008Rizaldi Sistiabudi Dip-pen nanolithography is used to directly modify freshly dissected eye tissues with biologically active collagen-binding peptide molecules. The results address the challenge of surface heterogeneity and utilize dip-pen nanolithography to control the localization and concentration of molecules on a collagen-terminated tissue-derived surface. This method can allow the development of scaffolds for treatment of age-related macular degeneration. [source] The Journal of Peptide Science,Special Issue dedicated to the 10th Naples workshop on Bioactive PeptidesJOURNAL OF PEPTIDE SCIENCE, Issue 12 2006Ettore Benedetti [source] A New Frontier in Soy Bioactive Peptides that May Prevent Age-related Chronic DiseasesCOMPREHENSIVE REVIEWS IN FOOD SCIENCE AND FOOD SAFETY, Issue 4 2005Wenyi Wang ABSTRACT During gastrointestinal digestion or food processing of proteins, small peptides can be released and may act as regulatory compounds with hormone-like activities. Numerous biologically active peptides (bioactive peptides) have been identified. Most bioactive peptides are derived from milk and dairy products, with the most common being angiotensin converting enzyme inhibitory peptides. Soybean protein and soybean derived peptides also play an important role in soybean physiological activities, particularly those related to the prevention of chronic diseases. However, the bioactive potential of soybean derived bioactive peptides is yet to be fully appreciated. After a general introduction of approaches and advances in bioactive peptides from food sources, this review focuses on bioactive peptides derived from soybean proteins and their physiological properties. Technological approaches to generate bioactive peptides, their isolation, purification, characterization, and quantification, and further application in food and drug design are also presented. Safety concerns, such as potential toxicity, allergenicity, and sensory aspect of these peptides are likewise discussed. [source] C-peptide makes a comebackDIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 5 2003John Wahren Proinsulin C-peptide was for long considered to be without biological activity of its own. New findings demonstrate, however, that it is capable of eliciting both molecular and physiological effects, suggesting that C-peptide is in fact a bioactive peptide. When administered in replacement doses to animal models or to patients with type 1 diabetes, C-peptide ameliorates diabetes-induced functional and structural changes in both the kidneys and the peripheral nerves. It augments blood flow in a number of tissues, notably skeletal muscle, myocardium, skin and nerve. These effects are thought to be mediated via a stimulatory influence on Na+,K+ -ATPase and on endothelial nitric oxide synthase. Specific binding of C-peptide to cell membranes of intact cells and to detergent-solubilized cellular components has been demonstrated, indicating the existence of cell-surface binding sites for C-peptide. A number of intracellular responses are elicited by C-peptide, including a rise in Ca2+ concentration and activation of MAP-kinase signaling pathways. Many but not all of C-peptide's intracellular effects can be inhibited by pertussis toxin, supporting the notion that C-peptide may interact via a G-protein-coupled receptor. Additional data suggest that C-peptide may interact synergistically also in the insulin signaling pathway. Combined, the available observations show conclusively that C-peptide is biologically active, even though its molecular mechanism of action is not as yet fully understood. The possibility that replacement of C-peptide in patients with type 1 diabetes may serve to retard or prevent the development of long-term complications should be evaluated. Copyright © 2003 John Wiley & Sons, Ltd. [source] Angiotensin II/angiotensin II type I receptor (AT1R) signaling promotes MCF-7 breast cancer cells survival via PI3-kinase/Akt pathwayJOURNAL OF CELLULAR PHYSIOLOGY, Issue 1 2010Yanbin Zhao Angiotensin II (Ang II) is a bioactive peptide of the renin,angiotensin system, acting not only as a vasoconstrictor but also as a growth promoter via angiotensin II type 1 receptor (AT1R) in some cancer. In this study, we examined the mechanisms by which Ang II affected the cell proliferation in AT1R-positive MCF-7 human breast cancer cells. Ang II stimulated the growth of breast cancer cells in a dose- and time-dependent manner. The maximal proliferation effect on MCF-7 cells was obtained with 10,4,M Ang II at 24,h. Losartan (10,5,M, an AT1R antagonist) significantly decreased the level of Ang-II-induced proliferative effects, whereas PD123319 (10,5,M, an AT2R antagonist) had no effects. Moreover, Ang II could significantly accelerate S-phase progression, which was inhibited by losartan (10,5,M) or LY294002 (50,µM, a PI3-kinase inhibitor). In addition, Ang II caused rapid activation of p-Akt in a dose- and time-dependent manner. 10,4,M Ang II induced a significant increase of p-Akt in 15,min. The peak level of p-Akt could be persisted for at least 6,h. Among the signaling molecules downstream of Akt, we revealed that Ang II also significantly upregulated CyclinD1, GSK3,, and downregulated p27. Pretreatment with losartan (10,5,M) or LY294002 (50,µM) could significantly suppress these effects of Ang II. These findings suggest that Ang II plays a role in the growth of AT1R-positive breast cancer cells through PI3-kinase/Akt pathway activation. Therefore, targeting Ang II/AT1R signaling could be a novel therapeutic for breast cancer. J. Cell. Physiol. 225: 168,173, 2010. © 2010 Wiley-Liss, Inc. [source] Medium-sized peptides as built in carriers for biologically active compoundsMEDICINAL RESEARCH REVIEWS, Issue 6 2005Ferenc Hudecz Abstract A growing number of oligopeptides of natural and/or synthetic origin have been described and considered as targeting structures for delivery bioactive compounds into various cell types. This review will outline the discovery of peptide sequences and the corresponding mid-sized oligopeptides with membrane translocating properties and also summarize de novo designed structures possessing similar features. Conjugates and chimera constructs derived from these sequences with covalently attached bioactive peptide, epitope, oligonucleotide, PNA, drug, reporter molecule will be reviewed. A brief note will refer to the present understanding on the uptake mechanism at the end of each section. © 2005 Wiley Periodicals, Inc. Med Res Rev [source] Functionalized, Swellable Hydrogel Layers as a Platform for Cell StudiesADVANCED FUNCTIONAL MATERIALS, Issue 8 2009Núria Marí-Buyé Abstract This paper reports the design, synthesis and characterization of thin films as a platform for studying the separate influences of physical and chemical cues of a matrix on the adhesion, growth and final phenotype of cells. Independent control of the physical and chemical properties of functionalized, swellable hydrogel thin films is achieved using initiated chemical vapor deposition (iCVD). The systematic variation in crosslink density is demonstrated to control the swelling ability of the iCVD hydrogel films based on 2-hydroxyethyl methacrylate (HEMA). At the same time, the incorporation of controllable concentrations of the active ester pentafluorophenyl methacrylate (PFM) allows easy immobilization of aminated bioactive motifs, such as bioactive peptides. Initial cell culture results with human umbilical vein endothelial cells (HUVEC) indicate that the strategy of using PFM to immobilize a cell-adhesion peptide motif onto the hydrogel layers promotes proper HUVEC growth and enhances their phenotype. [source] Antimicrobial peptides generated from milk proteins: a survey and prospects for application in the food industry.INTERNATIONAL JOURNAL OF DAIRY TECHNOLOGY, Issue 3 2010A review Milk proteins constitute a natural reservoir of bioactive peptides with physiological and/or antimicrobial properties, the release of which requires hydrolysis of the precursor molecules by digestive proteases or by fermentation with proteolytic micro-organisms. Depending on the digestive or microbial proteases used, an array of bioactive peptides would be released either from caseins or whey proteins, but only a small part of these peptides has so far been identified and characterised with respect to their antimicrobial activity. The antimicrobial peptides known thus far have proven to be potent inhibitors to the growth of a wide range of undesirable micro-organisms of health or spoilage significance. Nevertheless, previous research work has largely been oriented towards their possible application in medicine, which has hindered their high potential as food-grade biopreservatives and/or as supplements in functional foods. This review attempts to study the literature pertaining to antimicrobial peptides derived from major milk proteins (caseins, ,-lactalbumin and ,-lactoglobulin) upon hydrolysis either by digestive proteases or by fermentation with proteolytic lactic acid bacteria. Their possible application in the food industry and their mechanism of action will also be discussed. Reference antimicrobial peptides produced by living micro-organisms as innate immune defence components against microbial infections will occasionally be invoked for comparison purposes. [source] Antihypertensive Activities of Peptides Derived from Porcine Skeletal Muscle Myosin in Spontaneously Hypertensive RatsJOURNAL OF FOOD SCIENCE, Issue 1 2002Y. Nakashima ABSTRACT: Antihypertensive activities derived from porcine skeletal muscle proteins were investigated. Thermolysin hydrolysates of porcine muscle water-insoluble proteins demonstrated antihypertensive activities in spontaneously hypertensive rats when administrated in single oral doses. Hydrolysates of porcine myosin and peptides (Met-Asn-Pro-Pro-Lys, Ile-Thr-Thr-Asn-Pro, Met-Asn-Pro, Pro-Pro-Lys) with parts of the sequence of myosin showed antihypertensive activities. This is the first report of antihypertensive activities of peptides derived from muscle proteins of domestic animals. The hydrolysates of porcine muscle protein and their corresponding bioactive peptides might be utilized for physiologically functional foods. [source] 18F-glycosylation using Koenigs,Knorr conditions: a comparative studyJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 2 2006Simone Maschauer Abstract We compared two 18F-glycosylation methods, the BF3 -mediated 18F-glycosylation versus the newly developed AgOTf-activated 18F-glycosylation procedure. The AgOTf-activated 18F-glycosylation makes use of 3,4,6-tri-O-acetyl-2-deoxy-2-[18F]fluoro-glucopyranosyl bromide and revealed an improved radiochemical yield of 67±6% in the case of a protected serinyl precursor as compared to 27±4% obtained by the BF3 -method. This suggests the suitability of Koenigs,Knorr conditions for 18F-glycosylation of protected bioactive peptides. Copyright © 2006 John Wiley & Sons, Ltd. [source] Utility of 1,3,4,6-tetra- O -acetyl-2-deoxy-2-[18F]fluoro-glucopyranoside for no-carrier-added 18F-glycosylation of amino acidsJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 10 2005Simone Maschauer Abstract A radiochemical method for the 18F-glycosylation of amino acid side chains was developed starting from peracetylated 2-deoxy-2-[18F]fluoroglucopyranoside (TA-[18F]FDG). O -(2-deoxy-2-[18F]fluoro- D -glucopyranosyl)- L -serine and the corresponding threonyl compound were obtained in a radiochemical yield of 25% and 12% (related to [18F]fluoride), respectively, after Zemplén deprotection within a total reaction time of 90 min. The anomeric configuration of the corresponding 19F-substituted compounds revealed preferential , -stereoselectivity. The 18F-glycosylation method using TA-[18F]FDG is compatible with the short half-life of fluorine-18 and combines glycosylation and 18F-labelling of a target compound within a single reaction step. TA-[18F]FDG is a promising 18F-labelled prosthetic group and could be adapted to 18F-labelling of bioactive peptides to study their pharmacokinetics using positron emission tomography (PET). Copyright © 2005 John Wiley & Sons, Ltd. [source] Studies on the molecular recognition between bioactive peptides and angiotensin-converting enzymeJOURNAL OF MOLECULAR RECOGNITION, Issue 2 2009A.S. Pina Abstract High blood pressure or hypertension is a condition affecting many individuals and represents a controllable risk factor for cardiovascular diseases such as coronary heart disease and stroke. A non-pharmacological approach to manage these includes the application of food components with antihypertensive activity. Milk protein-derived peptides have been exploited as natural hypotensive agents, namely the peptides Val-Pro-Pro (VPP) and Ile-Pro-Pro (IPP), already commercialized in functional foods as a potential alternative to synthetic drugs. These bioactive peptides inhibit in vitro and in vivo the Angiotensin I-converting enzyme (ACE), a protein with an important role in blood pressure regulation. In this work, we attempted to elucidate the possible mode of interaction between the peptides and ACE, including mechanisms of binding to the cofactor Zn2+, and further contrast this with the known mode of inhibition exerted by synthetic drugs (Captopril, Enalaprilat and Lisinopril). The bioactive peptide Ala-Leu-Pro-Met-His-Ile-Arg (ALPMHIR), also known to inhibit the enzyme ACE but with a lower efficiency than VPP and IPP, was utilized in the docking studies for comparison. It was observed that the best docking poses obtained for VPP and IPP were located at the ACE catalytic site with very high resemblance to the drugs mode of interaction, including the coordination with Zn2+. As for ALPMHIR, the best docking poses were located in the narrow ACE channel outside the catalytic site, representing higher affinity energies and fewer resemblances with the interaction established by drugs. Copyright © 2008 John Wiley & Sons, Ltd. [source] Chromogranins as regulators of exocytosisJOURNAL OF NEUROCHEMISTRY, Issue 2 2010Ricardo Borges J. Neurochem. (2010) 114, 335,343. Abstract Chromogranins (Cgs) constitute the main protein component in the vesicular matrix of large dense core vesicles (LDCV). These acidic proteins have been implicated in several physiological processes such as vesicle sorting, the generation of bioactive peptides and the accumulation of soluble species inside LDCV. This latter feature of Cgs accounts for the ability of vesicles to concentrate catecholamines and Ca2+. Indeed, the low affinity and high capacity of Cgs to bind solutes at the low pH of the LDCV lumen seems to be behind the delay in the neurotransmitter exit towards the extracellular milieu after vesicle fusion. The availability of new mouse strains lacking Cgs in combination with the arrival of several techniques for the direct monitoring of exocytosis (like amperometry, patch-amperometry and intracellular electrochemistry), have helped advance our understanding of how these granins concentrate catecholamines and Ca2+ in LDCV, and how they influence the kinetics of exocytosis. In this review, we will discuss the roles of Cgs A and B in maintaining the intravesicular environment of secretory vesicles and in exocytosis, bringing together the most recent findings from adrenal chromaffin cells. [source] Microwave-assisted TFA cleavage of peptides from Merrifield resinJOURNAL OF PEPTIDE SCIENCE, Issue 1 2010Alicja Kluczyk Abstract Microwave-assisted (MW) reactions are of special interest to the chemical community due to faster reaction times, cleaner reactions and higher product yields. The adaptation of MW to solid phase peptide synthesis resulted in spectacular syntheses of difficult peptides. In the case of Merrifield support, used frequently in synthesis of special peptides, the conditions used in product cleavage are not compatible with off-resin monitoring of the reaction progress. The application of MW irradiation in product removal from Merrifield resin using trifluoroacetic acid (TFA) was investigated using model tetrapeptides and the effects were compared with standard trifluoromethanesulphonic acid (TFMSA) cleavage using elemental analysis as well as chromatographic (HPLC) and spectroscopic (IR) methods. The deprotection of benzyloxycarbonyl and benzyl groups in synthetic bioactive peptides was analyzed using LC-MS and MS/MS experiments. In a 5 min microwave-assisted TFA reaction at low temperature, the majority of product is released from the resin, making the analytical scale MW-assisted procedure a method of choice in monitoring the reactions carried out on Merrifield resin due to the short reaction time and compatibility with HPLC and ESI-MS conditions. Copyright © 2009 European Peptide Society and John Wiley & Sons, Ltd. [source] A novel solid phase approach to Aia-containing peptidesJOURNAL OF PEPTIDE SCIENCE, Issue 1 2009Debby Feytens Abstract A strategy was developed to directly assemble 4-amino-1,2,4,5-tetrahydro-indolo[2,3- c]-azepin-3-ones on solid-phase-supported peptide sequences. Fmoc- and Boc-based strategies were investigated. The Fmoc-strategy approach strongly depends on the peptide sequence being synthesized while the Boc-based synthesis leads to excellent results for all the selected peptide analogs. The method was applied to prepare Aia-analogs of several bioactive peptides containing one or more Trp-residues which were shown to be important for biological recognition. Copyright © 2008 European Peptide Society and John Wiley & Sons, Ltd. [source] Small peptides, big world: biotechnological potential in neglected bioactive peptides from arthropod venoms,JOURNAL OF PEPTIDE SCIENCE, Issue 11 2005Adriano M. C. Pimenta Abstract Until recently, a toxinologist's tasks involved the search for highly toxic or lethal toxins in animal venoms that could explain the harmful effects in clinically observed symptoms. Most of these toxins were put on evidence using a function to structure approach, in which a biological phenomena observation usually guided the isolation and characterization of the causative molecule. Paving this way, many toxins were promptly purified because of their readily observed effect. Nevertheless, small molecules with micro-effects that are not easily visualized can be relatively neglected or poorly studied. This situation has changed now with the advent of the sensitivity, resolution and accuracy of techniques such as mass spectrometry and proteomic approaches used in toxinology. Taking advantage of these methodologies, small peptides with ,newly exploited' biological activities such as vasoactive, hormone-like, antimicrobial and others have been recently given much more attention, enlarging the known repertoire of bioactive molecules found in animal venoms. This article aims to review current knowledge on small biologically active peptides (<3 kDa) found in arthropod venoms and discuss their potentialities as new drug candidates or therapeutic lead compounds. Copyright © 2005 European Peptide Society and John Wiley & Sons, Ltd. [source] Bioactive peptide production by hydrolysis of porcine blood proteins in a continuous enzymatic membrane reactorJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 3 2009Jen-Ting Wei Abstract BACKGROUND: During slaughter a hog produces approximately 3 L of blood. However, only a small proportion of porcine blood is currently used in food, feed or fertiliser, most of it being treated as waste and discarded. In this study the possibility of hydrolysing porcine blood proteins by enzyme in a membrane reactor for the production of bioactive peptides was investigated. Red blood corpuscles, blood plasma and defibrinated blood plasma were hydrolysed by various proteases, and the hydrolysates were evaluated for bioactive properties. RESULTS: The hydrolysate produced by hydrolysing red blood corpuscles with a mixture of trypsin, chymotrypsin and thermolysin had the highest angiotensin I-converting enzyme (ACE)-inhibitory activity (IC50 = 0.58 mg mL,1) and scavenging effect on ,,,-diphenyl-,-picrylhydrazyl (DPPH) (65%) after 6 and 10 h of hydrolysis respectively. When the hydrolysis was carried out in an enzymatic membrane reactor with an enzyme/substrate ratio of 1:5 and a residence time of 100 min, the process reached steady state in 2 h. The ACE-inhibitory activity of the product during the steady state process was 86% and its scavenging effect on DPPH was 54%. The membrane process also decolourised the enzyme-hydrolysed product, thus improving the appearance of the product. CONCLUSION: This study demonstrated that hydrolysates of porcine blood possess antihypertensive and antioxidant activities. Using red blood corpuscles as the substrate, the hydrolysis could be carried out in a membrane reactor with a mixture of proteases to produce bioactive peptides continuously. Therefore processing of porcine blood in an enzymatic membrane reactor is a potential method for producing a health-promoting product. Copyright © 2008 Society of Chemical Industry [source] Transformation of antimicrobial into bradykinin-potentiating peptides during peptic hydrolysis of bovine haemoglobin: identification, release kinetics and reaction network of peptidesJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 3 2007Wei Qi Abstract The precursor cleavage of the antimicrobial peptide ,107,136 into the bradykinin-potentiating peptide ,110,125 during peptic hydrolysis of bovine haemoglobin was investigated by reverse phase high-performance liquid chromatography coupled with tandem mass spectrometry. The optimal conditions for the preparation of ,107,136 and ,110,125 were found to be low and high degrees of hydrolysis respectively. A total of six peptides were identified as being involved in the cleavage process. Moreover, the reaction network of these peptides was developed according to the sequence alignment and their release kinetics. The affinity of pepsin towards different peptide bonds of bovine haemoglobin was also compared based on data from the release kinetics of peptides. In addition, some potentially bioactive peptides were predicted by means of sequence analysis and secondary structure calculations. Copyright © 2006 Society of Chemical Industry [source] Electrospun, Biofunctionalized Fibers as Tailored in vitro Substrates for Keratinocyte Cell CultureMACROMOLECULAR BIOSCIENCE, Issue 9 2010Dirk Grafahrend Abstract Cell adhesion preventing fiber surfaces were tailored differently with bioactive peptides (a fibronectin fragment (GRGDS), a collagen IV fragment (GEFYFDLRLKGDK) and a combination of both) to provide an artificial extracellular matrix as a substrate for HaCaT keratinocyte cell culture. Therefore, a polymer blend containing a six-arm star-shaped statistical copolymer of ethylene oxide and propylene oxide in the ratio 80:20 (NCO- sP[EO- co -PO]) and poly-[D,L -(lactide- co -glycolide)] (PLGA) was electrospun. The resulting fibers were biofunctionalized and investigated as in vitro substrates using the HaCaT kerationcyte cell line. Appropriate surface chemistry on these electrospun fibers proved to prevent adhesion of keratinocytes, while additional immobilization of certain peptide sequences induced cell adhesion. These specific fibers enable investigation of immobilized active molecules and the subsequent cellular response to the scaffold. HaCaT keratinocytes were found to selectively adhere to those fibers modified with either collagen IV segment GEFYFDLRLKGDK or a mixture of the two peptide sequences GEFYFDLRLKGDK and GRGDS (1:1). However, the synergistic effects of both (the fibronectin fragment and the collagen IV fragment) seem to significantly increase the numbers of adherent keratinocytes. [source] Peptide-based radiopharmaceuticals: Future tools for diagnostic imaging of cancers and other diseasesMEDICINAL RESEARCH REVIEWS, Issue 3 2004S.M. Okarvi Abstract An Erratum has been published for this article in Medicinal Research Reviews 2004;24:685,686. Small synthetic receptor-binding peptides are the agents of choice for diagnostic imaging and radiotherapy of cancers due to their favorable pharmacokinetics. Molecular modification techniques permit the synthesis of a variety of bioactive peptides with chelating groups, without compromising biological properties. Various techniques have been developed that allow efficient and site-specific labeling of peptides with clinically useful radionuclides such as 99mTc, 123I, 111In, and 18F. Among them, 99mTc is the radionuclide of choice because of its excellent chemical and imaging characteristics. Recently, many 99mTc-labeled peptides have proven to be useful imaging agents. Beside 99mTc-labeled peptides, several peptides radiolabeled with 111In and 123I have been prepared and characterized. In addition, 18F-labeled peptides hold clinical potential due to their ability to quantitatively detect and characterize a variety of human diseases using positron-emission tomography. The availability of this wide range of peptides labeled with different radionuclides offers multiple diagnostic and therapeutic applications. Various receptors are over-expressed in particular tumor types and peptides binding to these receptors can be used to visualize tumor lesions scintigraphically. Thus, radiolabeled peptides have potential use as carriers for the delivery of radionuclides to tumors, infarcts, and infected tissues for diagnostic imaging and radiotherapy. Many radiolabeled peptides are currently under investigation to determine their potential as imaging agents. These peptides are designed mainly for thrombus, tumor, and infection/inflammation imaging. This article presents recent developments in small synthetic peptides for imaging of thrombosis, tumors, and infection/inflammation. © 2004 Wiley Periodicals, Inc. Med Res Rev, 24, No. 3, 357,397, 2004 [source] Proopiomelanocortin gene expression and ,-endorphin localization in the pituitary, testis, and epididymis of stallionMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 1 2006L. Soverchia Abstract Proopiomelanocortin (POMC) is a precursor protein that contains the sequences of several bioactive peptides including adrenocorticotropin (ACTH), ,-endorphin (,-EP), and melanocyte-stimulating-hormone (MSH). POMC is synthesized in the pituitary gland, brain, and many peripheral tissues. Immunoreactive POMC-derived peptides as well as POMC-like mRNA have been evidenced in several nonpituitary tissues, thus suggesting that POMC is actively synthesized by these tissues. The present study was aimed at evaluating if also in the case of stallion POMC-derived peptide, ,-EP, is produced locally in the testis, thus playing effects in a paracrine/autocrine fashion. To investigate this hypothesis the POMC gene expression was analyzed using 3, RACE-PCR and Northern Blot approaches in the testis and epididimys of stallion; moreover, immunocytochemical localization for ,-EP was also performed through confocal laser microscopy. The immunofluorescence results showed a positive ,-EP reaction not only in cellular nest of pituitary but also in the testis and genital tract of stallion, which function could be related with sperm mobility. Such role seem not to be no dependent on the peptide synthesized locally, because the molecular biology approach demonstrated the presence of POMC transcript in the pituitary only. In fact the Northern Blot analysis showed the presence of a single POMC transcript in the pituitary while no signal was detected in the testis and epididimys. The same results were obtained by applied 3, RACE-PCR analysis. In conclusion, opioid-derived peptide ,-EP is present in the genital tract of stallion, but is not locally produced as in other mammalian, and nonmammalian models; its possible biological function at testicular level could be linked to a long-loop feed-back mechanisms. Mol. Reprod. Dev. © 2005 Wiley-Liss, Inc. [source] Enamel matrix proteins; old molecules for new applicationsORTHODONTICS & CRANIOFACIAL RESEARCH, Issue 3 2009SP Lyngstadaas Structured Abstract Authors,,, Lyngstadaas SP, Wohlfahrt JC, Brookes SJ, Paine ML, Snead ML, Reseland JE Emdogain® (enamel matrix derivative, EMD) is well recognized in periodontology, where it is used as a local adjunct to periodontal surgery to stimulate regeneration of periodontal tissues lost to periodontal disease. The biological effect of EMD is through stimulation of local growth factor secretion and cytokine expression in the treated tissues, inducing a regenerative process that mimics odontogenesis. The major (>95%) component of EMD is Amelogenins (Amel). No other active components have so far been isolated from EMD, and several studies have shown that purified amelogenins can induce the same effect as the complete EMD. Amelogenins comprise a family of highly conserved extracellular matrix proteins derived from one gene. Amelogenin structure and function is evolutionary well conserved, suggesting a profound role in biomineralization and hard tissue formation. A special feature of amelogenins is that under physiological conditions the proteins self-assembles into nanospheres that constitute an extracellular matrix. In the body, this matrix is slowly digested by specific extracellular proteolytic enzymes (matrix metalloproteinase) in a controlled process, releasing bioactive peptides to the surrounding tissues for weeks after application. Based on clinical and experimental observations in periodontology indicating that amelogenins can have a significant positive influence on wound healing, bone formation and root resorption, several new applications for amelogenins have been suggested. New experiments now confirm that amelogenins have potential for being used also in the fields of endodontics, bone regeneration, implantology, traumatology, and wound care. [source] Development and characterization of a fusion protein between thermally responsive elastin-like polypeptide and interleukin-1 receptor antagonist: Sustained release of a local antiinflammatory therapeuticARTHRITIS & RHEUMATISM, Issue 11 2007Mohammed F. Shamji Objective Interleukin-1 receptor antagonist (IL-1Ra) has been evaluated for the intraarticular treatment of osteoarthritis. Such administration of proteins may have limited utility because of their rapid clearance and short half-life in the joint. The fusion of a drug to elastin-like polypeptides (ELPs) promotes the formation of aggregating particles that form a "drug depot" at physiologic temperatures, a phenomenon intended to prolong the presence of the drug. The purpose of this study was to develop an injectable drug depot composed of IL-1Ra and ELP domains and to evaluate the properties and bioactivity of the recombinant ELP-IL-1Ra fusion protein. Methods Fusion proteins between IL-1Ra and 2 distinct sequences and molecular weights of ELP were overexpressed in Escherichia coli. Environmental sensitivity was demonstrated by turbidity and dynamic light scattering as a function of temperature. IL-1Ra domain activity was evaluated by surface plasmon resonance, and in vitro antagonism of IL-1,mediated lymphocyte and thymocyte proliferation, as well as IL-1,induced tumor necrosis factor , (TNF,) expression and matrix metalloproteinase 3 (MMP-3) and ADAMTS-4 messenger RNA expression in human intervertebral disc fibrochondrocytes. IL-1Ra immunoreactivity was assessed before and after proteolytic degradation of the ELP partner. Results Both fusion proteins underwent supramolecular aggregation at subphysiologic temperatures and slowly resolubilized at 37°C. Interaction with IL-1 receptor was slower in association but equivalent in dissociation as compared with the commercial antagonist. Anti,IL-1 activity was demonstrated by inhibition of lymphocyte and thymocyte proliferation and by decreased TNF, expression and ADAMTS-4 and MMP-3 transcription by fibrochondrocytes. ELP domain proteolysis liberated a peptide of comparable size and immunoreactivity as the commercial IL-1Ra. This peptide was more bioactive against lymphocyte proliferation, nearly equivalent to the commercial antagonist. Conclusion The ELP-IL-1Ra fusion protein proved to retain the characteristic ELP inverse phase-transitioning behavior as well as the bioactivity of the IL-1Ra domain. This technology represents a novel drug carrier designed to prolong the presence of bioactive peptides following intraarticular delivery. [source] Electro-membrane filtration for the selective isolation of bioactive peptides from an ,s2 -casein hydrolysateBIOTECHNOLOGY & BIOENGINEERING, Issue 6 2002Gerrald Bargeman Abstract For the isolation of the ingredients required for functional foods and nutraceuticals generally membrane filtration has too low a selectivity and chromatography is (too) expensive. Electro-membrane filtration (EMF) seems to be a breakthrough technology for the isolation of charged nutraceutical ingredients from natural sources. EMF combines the separation mechanisms of membrane filtration and electrophoresis. In this study, positively charged peptides with antimicrobial activity were isolated from an ,s2 -casein hydrolysate using batch-wise EMF. ,s2 -Casein f(183,207), a peptide with strong antimicrobial activity, predominated in the isolated product and was enriched from 7.5% of the total protein components in the feed to 25% in the permeate product. With conventional membrane diafiltration using the same membrane (GR60PP), isolation of this and other charged bioactive peptides could not be achieved. The economics of EMF are mainly governed by the energy costs and the capital investment, which is affected by the flux of the desired peptide. A maximum average transport rate of ,s2 -casein f(183,207) during batch-wise EMF of 1.2 g/m2 · h was achieved. Results indicate that an increase in the hydrolysate (feed) concentration, the applied potential difference and the conductivity of the permeate and electrode solutions, and a reduction in the conductivity of the feed result in a higher transport rate of ,s2 -casein f(183,207). This is in line with the expectation that the transport rate is improved when the concentration, the electrical field strength, or the electrophoretic mobility is increased, provided that the electrophoretic transport predominates. The expected energy consumption of the EMF process per gram of peptide transported was reduced by approximately 50% by applying a low overall potential difference and by processing desalinated hydrolysate. Considerable improvements in transport rate, energy efficiency, and process economics seem to be attainable by additional optimization of the process parameters and the EMF module design. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 80: 599,609, 2002. [source] A New Frontier in Soy Bioactive Peptides that May Prevent Age-related Chronic DiseasesCOMPREHENSIVE REVIEWS IN FOOD SCIENCE AND FOOD SAFETY, Issue 4 2005Wenyi Wang ABSTRACT During gastrointestinal digestion or food processing of proteins, small peptides can be released and may act as regulatory compounds with hormone-like activities. Numerous biologically active peptides (bioactive peptides) have been identified. Most bioactive peptides are derived from milk and dairy products, with the most common being angiotensin converting enzyme inhibitory peptides. Soybean protein and soybean derived peptides also play an important role in soybean physiological activities, particularly those related to the prevention of chronic diseases. However, the bioactive potential of soybean derived bioactive peptides is yet to be fully appreciated. After a general introduction of approaches and advances in bioactive peptides from food sources, this review focuses on bioactive peptides derived from soybean proteins and their physiological properties. Technological approaches to generate bioactive peptides, their isolation, purification, characterization, and quantification, and further application in food and drug design are also presented. Safety concerns, such as potential toxicity, allergenicity, and sensory aspect of these peptides are likewise discussed. [source] | |||||||||||||||||||