Bioactive peptides derived from natural proteins with respect to diversity of their receptors and physiological effects
Publication date: Available online 19 August 2015 Source:Peptides Author(s): Masaaki Yoshikawa Bioactive peptide sequences are encrypted in natural proteins which have not been regarded as precursor roles. We isolated bioactive peptides which act by binding to receptors of endogenous bioactive peptides such as opioids, neurotensin, bradykinin, complements C3a and C5a, formyl peptide, and oxytocin from enzymatic digests not only from animal but also from plant proteins. Although the affinities of these peptides for receptors are much smaller than those of endogenous peptides, they exhibited central effects such as modula...
Source: Peptides - August 19, 2015 Category: Biochemistry Source Type: research

Neurotensin enhances glutamatergic EPSCs in VTA neurons by acting on different neurotensin receptors
Publication date: Available online 18 August 2015 Source:Peptides Author(s): Poulomee Bose, Pierre-Paul Rompré, Richard A. Warren Neurotensin (NT) is an endogenous neuropeptide that modulates dopamine and glutamate neurotransmission in several limbic regions innervated by neurons located in the ventral tegmental area (VTA). While several studies showed that NT exerted a direct modulation on VTA dopamine neurons less is known about its role in the modulation of glutamatergic neurotransmission in this region. The present study was aimed at characterising the effects of NT on glutamate-mediated responses in differ...
Source: Peptides - August 18, 2015 Category: Biochemistry Source Type: research

Preface: Festschrift to highlight the career of Abba J. Kastin as a founding editor, researcher, and educator in the peptide field
Publication date: Available online 11 August 2015 Source:Peptides Author(s): Weihong Pan (Source: Peptides)
Source: Peptides - August 12, 2015 Category: Biochemistry Source Type: research

The membrane-active amphibian peptide caerin 1.8 inhibits fibril formation of amyloid β1-42
Publication date: Available online 11 August 2015 Source:Peptides Author(s): Yanqin Liu, Tianfang Wang, Antonio N. Calabrese, John A. Carver, Scott F. Cummins, John H. Bowie. The amphibian host-defense peptide caerin 1.8 [1GLFKVLGSV10AKHLLPHVVP20VIAEKL(NH2)] inhibits fibril formation of amyloid β 1−42 [1DAEFRHDSG10YEVHHQKLVF20FAEDVGSNKG30AIIGLMVGGV40VIA] [Aβ42] (the major precursor of the extracellular fibrillar deposits of Alzheimer's disease). Some truncated forms of caerin 1.8 also inhibit fibril formation of Aβ42. For example, caerin 1.8 (1-13) [1GLFKVLGSV10AKHL(NH2) and caerin 1.8 (22-25) ...
Source: Peptides - August 12, 2015 Category: Biochemistry Source Type: research

Regulation of gut hormone secretion. Studies using isolated perfused intestines
Publication date: Available online 11 August 2015 Source:Peptides Author(s): Berit Svendsen, Jens Juul Holst The incretin hormones glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are secreted from enteroendocrine cells in the intestine along with other gut hormones (PYY, CCK and Neurotensin) shown to affect metabolism and/or appetite. The secretion of many gut hormones is highly increased after gastric bypass operations, which have turned out to be an effective therapy of not only obesity and but also type 2 diabetes. These effects are likely to be due, at least in part, to increa...
Source: Peptides - August 12, 2015 Category: Biochemistry Source Type: research

PACAP as a neuroprotective factor in ischemic neuronal injuries
Publication date: Available online 11 August 2015 Source:Peptides Author(s): Seiji Shioda, Tomoya Nakamachi Pituitary adenylate cyclase-activating polypeptide (PACAP) is a 27- or 38-amino acid neuropeptide, which belongs to the vasoactive intestinal polypeptide/glucagon/secretin family. PACAP and its three receptor subtypes are expressed in neural tissues, with PACAP known to exert pleiotropic effects on the nervous system. This review provides an overview of current knowledge regarding the neuroprotective effects, mechanisms of action, and therapeutic potential of PACAP in response to ischemic brain injuries. (Source: Peptides)
Source: Peptides - August 12, 2015 Category: Biochemistry Source Type: research

Up-regulation of the kinin B2 receptor pathway modulates the TGF-β/Smad signaling cascade to reduce renal fibrosis induced by albumin
Publication date: Available online 6 August 2015 Source:Peptides Author(s): Areli Cárdenas, Javiera Campos, Pamela Ehrenfeld, Sergio Mezzano, Marta Ruiz-Ortega, Carlos D. Figueroa, Leopoldo Ardiles The presence of high protein levels in the glomerular filtrate plays an important role in renal fibrosis, a disorder that justifies the use of animal models of experimental proteinuria. Such models have proved useful as tools in the study of the pathogenesis of chronic, progressive renal disease. Since bradykinin and the kinin B2 receptor (B2R) belong to a renoprotective system with mechanisms still unclarified, ...
Source: Peptides - August 7, 2015 Category: Biochemistry Source Type: research

Mas receptor Overexpression Increased Ang-(1-7) Relaxation Response in Renovascular Hypertensive Rat Carotid
Publication date: Available online 6 August 2015 Source:Peptides Author(s): V.C. Olivon, R.D. Aires, L.B. Santiago, L.Z.N. Ramalho, S.F. Cortes, V.S. Lemos Renin-angiotensin system (RAS) is an important factor in the pathophysiology of hypertension. Mas receptor, Angiotensin-(1-7) [Ang-(1-7)]-activated receptor, is an important RAS component and exerts protective effects in the vasculature. Ang-(1–7) vascular effects and Mas receptor expression in carotid from renovascular hypertensive (2K-1C) rats is not clear. In the present study we investigated Mas receptor vasodilator response activated by Ang-(1–7...
Source: Peptides - August 7, 2015 Category: Biochemistry Source Type: research

Neuropeptide S Increases Locomotion Activity through Corticotropin-Releasing Factor Receptor 1 in Substantia Nigra of Mice
In conclusion, these results indicate that NPS-NPSR system may regulate locomotion together with the CRF1 system in SN. (Source: Peptides)
Source: Peptides - August 2, 2015 Category: Biochemistry Source Type: research

Oxytocin differentially effects 3β-hydroxysteroid dehydrogenase and 5α-reductase activities in prostate cancer cell lines
This study demonstrates differential effects of oxytocin on the activities of key de novo steroidogenic enzymes in prostate cancer cells. (Source: Peptides)
Source: Peptides - August 2, 2015 Category: Biochemistry Source Type: research

Antifungal activity of cathelicidin peptides against planktonic and biofilm cultures of Candida species isolated from vaginal infections
Publication date: Available online 31 July 2015 Source:Peptides Author(s): Michele Scarsini, Linda Tomasinsig, Alessandra Arzese, Francesca D’Este, Debora Oro, Barbara Skerlavaj Vulvovaginal candidiasis (VVC) is a frequent gynecological condition caused by C. albicans and a few non-albicans Candida spp. It has a significant impact on the quality of life of the affected women also due to a considerable incidence of recurrent infections that are difficult to treat. The formation of fungal biofilm may contribute to the problematic management of recurrent VVC due to the intrinsic resistance of sessile cells to th...
Source: Peptides - July 31, 2015 Category: Biochemistry Source Type: research

Characterization of GnRH-like peptides from the nerve ganglia of Yesso scallop, Patinopecten yessoensis.
The objective of this paper is to characterize candidate invGnRH peptides of Yesso scallop Patinopecten yessoensis (i.e., peptide identification, immunohistochemical localization, and immunoquantification) in order to reveal their bioactive form in bivalves. Using mass spectrometry (MS) we identified two invGnRH (py-GnRH) peptides from the scallop nerve ganglia: a precursor form of py-GnRH peptide (a non-amidated dodecapeptide; py-GnRH12aa-OH) and a mature py-GnRH peptide (an amidated undecapeptide; py-GnRH11aa-NH2). Immunohistochemical staining allowed the localization of both py-GnRH peptides in the neuronal cell bodies ...
Source: Peptides - July 31, 2015 Category: Biochemistry Source Type: research

The ATPase activity of the mycobacterial plasma membrane is inhibited by the LL37-analogous peptide LLAP
Publication date: Available online 26 July 2015 Source:Peptides Author(s): Sandra Chingaté, Gabriela Delgado, Luz Mary Salazara, Carlos-Yesid Soto The emergence of multidrug-resistant Mycobacterium tuberculosis strains has led to the development of new antituberculous agents. In this context, antimicrobial targeting proteins to the cell membrane are interesting due to the avoidance of the plasma membrane permeation. Through this study, the antimicrobial activity, cellular toxicity, as well as the effect on the mycobacterial cell membrane ATPase activity of a cathelicidin-analogous peptide were assessed. By usi...
Source: Peptides - July 27, 2015 Category: Biochemistry Source Type: research

Oxytocin differentially effects 3 β-hydroxysteroid dehydrogenase and 5 α-reductase activities in prostate cancer cell lines
This study demonstrates differential effects of oxytocin on the activities of key de novo steroidogenic enzymes in prostate cancer cells. (Source: Peptides)
Source: Peptides - July 27, 2015 Category: Biochemistry Source Type: research

Signalling pathways involved in the detection of peptones by murine small intestinal enteroendocrine L-cells
Publication date: Available online 26 July 2015 Source:Peptides Author(s): Ramona Pais, Fiona M Gribble, Frank Reimann Glucagon like peptide-1 is an insulinotropic hormone released from intestinal L-cells in response to food ingestion. Here, we investigated mechanisms underlying the sensing of peptones by primary small intestinal L-cells. Meat, casein and vegetable-derived peptones (5mg/ml), the L-amino acids Phe, Trp, Gln and Ala (20mM each), and the dipeptide glycine-sarcosine (20mM) stimulated GLP-1 secretion from primary cultures prepared from the small intestine. Further mechanistic studies were performed with me...
Source: Peptides - July 27, 2015 Category: Biochemistry Source Type: research

Investigation into the mechanism of action of the antimicrobial peptides Os and Os-C derived from a tick defensin
Publication date: Available online 26 July 2015 Source:Peptides Author(s): Helena Taute, Megan J. Bester, Albert W.H. Neitz, Anabella R.M. Gaspar Os and Os-C are two novel antimicrobial peptides, derived from a tick defensin, which have been shown to have a larger range of antimicrobial activity than the parent peptide, OsDef2. The aim of this study was to determine whether the peptides Os and Os-C are mainly membrane acting, or if these peptides have possible additional intracellular targets in Escherichia coli and Bacillus subtilis. Transmission electron microscopy revealed that both peptides adversely affected int...
Source: Peptides - July 27, 2015 Category: Biochemistry Source Type: research

Pancreatic polypeptide responses to isoglycemic oral and intravenous glucose in humans with and without intact vagal innervation
Publication date: Available online 26 July 2015 Source:Peptides Author(s): Simon Veedfald, Astrid Plamboeck, Bolette Hartmann, Lars B. Svendsen, Tina Vilsbøll, Filip K. Knop, Jens J. Holst Secretion of pancreatic polypeptide (PP) from the pancreatic PP cells is controlled partly by vagal mechanisms. Release is stimulated by cephalic stimulation and enteral but not parenteral nutrients. Ambient glucose levels modulate circulating PP levels as hypoglycemia stimulates while hyperglycemia inhibits secretion. The glucose sensing mechanism has yet to be determined but may involve a vagal pathway. To investigate t...
Source: Peptides - July 27, 2015 Category: Biochemistry Source Type: research

Effects of systematic N-terminus deletions and benzoylations of endogenous RF-amide peptides on NPFF1R, NPFF2R, GPR10, GPR54 and GPR103
Publication date: Available online 23 July 2015 Source:Peptides Author(s): Laurent Rouméas, Jean-Paul Humbert, Séverine Schneider, Christelle Doebelin, Isabelle Bertin, Martine Schmitt, Jean-Jacques Bourguignon, Frédéric Simonin, Frédéric Bihel Mammalian RF-amide peptides including RF-amide-related peptides-1 and -3, neuropeptidesAF and FF, Prolactin releasing peptides, Kisspeptins and RFa peptides are currently consideredendogenous peptides for the GPCRs NPFF1R, NPFF2R, GPR10, GPR54 and GPR103,respectively. While NPFF1R and NPFF2R displayed high affinity for all the RF-...
Source: Peptides - July 24, 2015 Category: Biochemistry Source Type: research

Conserved molecular switch interactions in modeled cardioactive RF-NH2 peptide receptors: ligand binding and activation
Publication date: Available online 23 July 2015 Source:Peptides Author(s): M. Rasmussen, M. Leander, S. Ons, R. Nichols Peptides may act through G protein-coupled receptors to influence cardiovascular performance; thus, delineating mechanisms involved in signaling is a molecular-based strategy to influence health. Molecular switches, often represented by conserved motifs, maintain a receptor in an inactive state. However, once the switch is broken, the transmembrane regions move and activation occurs. The molecular switches of Drosophila melanogaster myosuppressin (MS) receptors were previously identified to include ...
Source: Peptides - July 24, 2015 Category: Biochemistry Source Type: research

Anti-tumoral activity of human salivary peptides
Publication date: Available online 23 July 2015 Source:Peptides Author(s): João Pinto da Costa, Virginia Carvalhais, Francisco Amado, Artur Silva, Rita Nogueira-Ferreira, Rita Ferreira, Luísa Helguero, Rui Vitorino Chemotherapy continues to be the standard treatment for advanced or metastasized cancer. However, commonly used chemotherapeutic agents may induce damage in healthy cells and tissues. Thus, in recent years, there has been an increased focus on the development of new, efficient anticancer drugs exhibiting low toxicity and that are not affected by mechanisms of chemoresistance. In the prese...
Source: Peptides - July 24, 2015 Category: Biochemistry Source Type: research

Spexin peptide is expressed in human endocrine and epithelial tissues and reduced after glucose load in type 2 diabetes
Publication date: Available online 23 July 2015 Source:Peptides Author(s): Liping Gu, Yuhang Ma, Mingyu Gu, Ying Zhang, Shuai Yan, Na Li, Yufan Wang, Xiaoying Ding, Jiajing Yin, Nengguang Fan, Yongde Peng Spexin mRNA and protein are widely expressed in rat tissues and associate with weight loss in rodents of diet- induced obesity. Its location in endocrine and epithelial cells has also been suggested. Spexin is a novel peptide that involves weight loss in rodents of diet-induced obesity. Therefore, we aimed to examine its expression in human tissues and test whether spexin could have a role in glucose and lipi...
Source: Peptides - July 24, 2015 Category: Biochemistry Source Type: research

Neuropeptide W modulation of gastric vagal afferent mechanosensitivity: Impact of age and sex
Conclusion The inhibitory effect of NPW on gastric tension sensitive and mucosal vagal afferents is age but not sex-dependent. These findings suggest the physiological role of NPW varies depending on the age of the mice. (Source: Peptides)
Source: Peptides - July 22, 2015 Category: Biochemistry Source Type: research

Vasoactive intestinal peptide (VIP) differentially affects inflammatory immune responses in human monocytes infected with viable Salmonella or stimulated with LPS
In conclusion, we show a differential effect of VIP on human monocytes infected with virulent Salmonella or stimulated with LPS. Our study suggests that the use of VIP in bacteraemia and/or sepsis may be limited to an adjunctive therapy to antibiotic treatment. (Source: Peptides)
Source: Peptides - July 21, 2015 Category: Biochemistry Source Type: research

Antimicrobial activity of human α-defensin 5 and its linear analogs: N-terminal fatty acylation results in enhanced antimicrobial activity of the linear analogs
In this study, we have investigated the antimicrobial activity of HD5 and linear analogs. Cysteine deletions attenuated the antibacterial activity considerably. Candidacidal activity was affected to a lesser extent. Fatty acid conjugated linear analogs showed antimicrobial activity comparable activity to HD5. Effective surface charge neutralization of bacteria was observed for HD5 as compared to the non-fatty acylated linear analogs. Our results show that HD5 and non-fatty acylated linear analogs enter the bacterial cytoplasm without causing damage to the bacterial inner membrane. Although fatty acylated peptides exhibited...
Source: Peptides - July 21, 2015 Category: Biochemistry Source Type: research

Nonsulfated cholecystokinins in the small intestine of pigs and rats
Publication date: Available online 20 July 2015 Source:Peptides Author(s): Mikkel Agersnap, Jens F. Rehfeld Cholecystokinin (CCK) is a gut hormone that acts via two receptors. The CCKA-receptor requires the tyrosyl residue in the C-terminal bioactive site of CCK to be O-sulfated, whereas the CCKB-receptor binds irrespective of sulfation. Consequently, unsulfated CCK peptides – if present – may constitute a hormone system that acts only through the CCKB-receptor. Therefore, we have now examined whether CCK peptides occur in nonsulfated form in the small intestine of pigs and rats. The concentrations of sulfa...
Source: Peptides - July 21, 2015 Category: Biochemistry Source Type: research

Altered serotonin (5-HT) 1D and 2A receptor expression may contribute to defective insulin and glucagon secretion in human type 2 diabetes
Publication date: Available online 20 July 2015 Source:Peptides Author(s): H. Bennet, A. Balhuizen, A. Medina, M. Dekker Nitert, E. Ottosson Laakso, S. Essén, P. Spégel, P. Storm, U. Krus, N. Wierup, M. Fex Islet produced 5-hydroxy tryptamine (5-HT) is suggested to regulate islet hormone secretion in a paracrine and autocrine manner in rodents. Hitherto, no studies demonstrate a role for this amine in human islet function, nor is it known if 5-HT signaling is involved in the development of beta cell dysfunction in type 2 diabetes (T2D). To clarify this, we performed a complete transcriptional map...
Source: Peptides - July 21, 2015 Category: Biochemistry Source Type: research

Botulinum neurotoxin: Progress in negating its neurotoxicity; and in extending its therapeutic utility via molecular engineering. MiniReview
Publication date: Available online 17 July 2015 Source:Peptides Author(s): Richard M. Kostrzewa, Rose Anna Kostrzewa, John P. Kostrzewa While the poisonous effects of botulinum neurotoxin (BoNT) have been recognized since antiquity, the overall actions and mechanisms of effects of BoNT have been elucidated primarily over the past several decades. The general utility of BoNT is described in the paper, but the focus is mainly on the approaches towards negating the toxic effects of BoNT, and on the projection of an engineered BoNT molecule serving as a Trojan Horse to deliver a therapeutic load for treatment of a host of...
Source: Peptides - July 18, 2015 Category: Biochemistry Source Type: research

Lipopeptide surfactants: Production, Recovery and Pore Forming Capacity
Publication date: Available online 17 July 2015 Source:Peptides Author(s): Mnif Inès, Ghribi Dhouha Lipopeptides are microbial surface active compounds produced by a wide variety of bacteria, fungi and yeast. They are characterized by highly structural diversity and have the ability to decrease the surface and interfacial tension at the surface and interface, respectively. Surfactin, Iturin and Fengycin of Bacillus subtilis are among the most studied lipopeptides. This review will present the main factors encountering lipopeptides production along with the techniques developed for their extraction and purificati...
Source: Peptides - July 18, 2015 Category: Biochemistry Source Type: research

Prior exercise does not alter the incretin response to a subsequent meal in obese women
Publication date: Available online 15 July 2015 Source:Peptides Author(s): Lauryn M Nyhoff, Timothy D Heden, Heather J Leidy, Nathan C Winn, Young-Min Park, John P Thyfault, Jill A Kanaley Prior research has shown an increase in GLP-1 concentrations during exercise but this exercise bout was conducted postprandially. The purpose of this study was to examine the incretin response to a meal following an exercise bout of different intensities in obese subjects. Eleven women (BMI>37.3±7.0 kg/m2; Age 24.3±4.6 y) participated in 3 counter-balanced study days where a standardized meal was preceded by...
Source: Peptides - July 16, 2015 Category: Biochemistry Source Type: research

The regulative effect of galanin family members on link of energy metabolism and reproduction
Publication date: Available online 15 July 2015 Source:Peptides Author(s): Penghua Fang, Biao He, Mingyi Shi, Guimei Kong, Xiaoyun Dong, Yan Zhu, Ping Bo, Zhenwen Zhang It is essential for the species survival that an efficient coordination between energy storage and reproduction through endocrine regulation. The neuropeptide galanin, one of the endocrine hormones, can potently coordinate energy metabolism and the activities of hypothalamic-pituitary-gonadal reproductive axis to adjust synthesis and release of metabolic and reproductive hormones in animals and humans. However, few papers have summarized the regul...
Source: Peptides - July 16, 2015 Category: Biochemistry Source Type: research

Engineering a peptide inhibitor towards the KCNQ1/KCNE1 potassium channel (IKs)
Publication date: Available online 15 July 2015 Source:Peptides Author(s): Youtian Hu, Jing Chen, Bin Wang, Weishan Yang, Chuangen Zhang, Jun Hu, Zili Xie, Zhijian Cao, Wenxin Li, Yingliang Wu, Zongyun Chen The KCNQ1/KCNE1 channel (IKs) plays important roles in the physiological and pathological process of heart, but no potent peptide acting on this channel has been reported. In this work, we found that the natural scorpion venom hardly inhibited KCNQ1/KCNE1 channel currents. Based on this observation, we attempted to use three natural scorpion toxins ChTX, BmKTX and OmTx2 with two different structural folds a...
Source: Peptides - July 16, 2015 Category: Biochemistry Source Type: research

Neuropeptide Y damages the integrity of mitochondrial structure and disrupts energy metabolism in cultured neonatal rat cardiomyocytes
Publication date: Available online 15 July 2015 Source:Peptides Author(s): Guochang Luo, Xuehua Xu, Wei Guo, Chengliang Luo, Hao Wang, Xiangzhi Meng, Shaohua Zhu, Yan Wei Neuropeptide Y (NPY) plays an important role in cardiovascular diseases including stress cardiomyopathy, hypertrophic cardiomyopathy, heart failure, diabetic cardiomyopathy, hypertension, and so on. However, inconsistent results related to the role of NPY in the different types of cardiomyopathies make the exact involvement of the peptide elusive. Considering these effects are known to be involved in energy balance, as the hearts energy producer...
Source: Peptides - July 16, 2015 Category: Biochemistry Source Type: research

Central acylated ghrelin improves memory function and hippocampal AMPK activation and partly reverses the impairment of energy and glucose metabolism in rats infused with β-amyloid
In conclusion, central acylated ghrelin in rats prevented the deterioration of memory function, and energy and glucose metabolisms were partially improved, possibly due to less β-amyloid accumulation. This research suggests that interventions such as intermittent fasting to facilitate sustained elevations of acyl-ghrelin should be investigated for cognitive and metabolic benefits, especially in person with early symptoms of memory impairment. (Source: Peptides)
Source: Peptides - July 15, 2015 Category: Biochemistry Source Type: research

Octadecaneuropeptide ODN prevents hydrogen peroxide-induced oxidative damage of biomolecules in cultured rat astrocytes
Publication date: Available online 2 July 2015 Source:Peptides Author(s): Yosra Hamdi , Hadhemi Kaddour , David Vaudry , Jérôme Leprince , Amira Zarrouk , Mohamed Hammami , Hubert Vaudry , Marie-Christine Tonon , Mohamed Amri , Olfa Masmoudi-Kouki Oxidative stress, associated with a variety of disorders including neurodegenerative diseases, is a major cause of cellular dysfunction and biomolecule damages which play a crucial role in neuronal apoptosis. Astrocytes specifically synthesize and release endozepines, a family of regulatory peptides, including the octadecaneuropeptide ODN. We have recently shown th...
Source: Peptides - July 14, 2015 Category: Biochemistry Source Type: research

Lipid derivatives activate GPR119 and trigger GLP-1 secretion in primary murine L-cells
Conclusions/interpretation GPR119 ligands strongly enhanced GLP-1 release from colonic cultures, reflecting the high proportion of colonic L-cells that exhibited cAMP responses to GPR119 agonists. Less GPR119-dependence could be demonstrated in the upper small intestine. In vivo, GPR119 in L-cells plays a key role in oral lipid-triggered GLP-1 secretion. (Source: Peptides)
Source: Peptides - July 14, 2015 Category: Biochemistry Source Type: research

High Fat Diet impairs the function of Glucagon-like Peptide-1 producing L-cells
Conclusion Mice fed on HFD exhibited reduced expression in L-cells of many L-cell specific genes, suggesting an impairment of enteroendocrine cell function. Our results suggest that a western style diet may detrimentally affect the secretion of gut hormones and normal post-prandial signalling, which could impact on insulin secretion and satiety. (Source: Peptides)
Source: Peptides - July 14, 2015 Category: Biochemistry Source Type: research

Hypothalamic inflammation and food intake regulation during chronic illness
Publication date: Available online 6 July 2015 Source:Peptides Author(s): J.T Dwarkasing , D.L. Marks , R.F Witkamp , K. van Norren Anorexia is a common symptom in chronic illness. It contributes to malnutrition and strongly affects survival and quality of life. A common denominator of many chronic diseases is an elevated inflammatory status, which is considered to play a pivotal role in the failure of food-intake regulating systems in the hypothalamus. In this review, we summarize findings on the role of hypothalamic inflammation on food intake regulation involving hypothalamic neuropeptide Y (NPY) and pro-opiomelanocor...
Source: Peptides - July 14, 2015 Category: Biochemistry Source Type: research

Glucagon and GLP-1 exhibit no synergistic enhancement of glucose-stimulated insulin secretion in mice
We examined whether complementary action of the two hormones also exist on insulin secretion. Female C57BL/6 mice were injected intravenously with glucose with or without GLP-1, glucagon or the combination of GLP-1 and glucagon at three different dose levels. Furthermore, freshly isolated mouse islets were incubated for 30min in the presence of 2.8, 11.1 or 16.7mmol/l glucose or with 11.1mmol/l glucose in the presence of 100nmol/l glucagon and/or GLP-1. It was found that at 1min after glucose injection alone, insulin rose to a peak level and this peak, as well as the 50min area under the insulin curve (AUC insulin) were do...
Source: Peptides - July 14, 2015 Category: Biochemistry Source Type: research

Chromofungin, CgA47-66-derived peptide, produces basal cardiac effects and postconditioning cardioprotective action during ischemia/reperfusion injury
Publication date: September 2015 Source:Peptides, Volume 71 Author(s): Elisabetta Filice , Teresa Pasqua , Anna Maria Quintieri , Patrizia Cantafio , Francesco Scavello , Nicola Amodio , Maria Carmela Cerra , Céline Marban , Francis Schneider , Marie-Hélène Metz-Boutigue , Tommaso Angelone Endogenous chromogranin A (CgA)-derived peptides are secreted by nervous, endocrine and immune cells. Chromofungin (Chr: CgA47-66) is one of these peptides that display antimicrobial activities and activate neutrophils, with important implications in inflammation and innate immunity. The aim of the present study is...
Source: Peptides - July 14, 2015 Category: Biochemistry Source Type: research

Antimicrobial peptides: Possible anti-infective agents
Publication date: Available online 3 June 2015 Source:Peptides Author(s): Jayaram Lakshmaiah Narayana , Jyh-Yih Chen Multidrug-resistant bacterial, fungal, viral, and parasitic infections are major health threats. The Infectious Diseases Society of America has expressed concern on the decrease of pharmaceutical companies working on antibiotic research and development. However, small companies, along with academic research institutes, are stepping forward to develop novel therapeutic methods to overcome the present healthcare situation. Among the leading alternatives to current drugs are antimicrobial peptides (AMPs), whi...
Source: Peptides - June 27, 2015 Category: Biochemistry Source Type: research

Understanding peptide biology: The discovery and characterization of the novel hormone, neuronostatin
We describe in this mini-review our strategy for determining neuronostatin's actions in brain, heart and pancreas. More importantly, we detail our deductive reasoning strategy for the identification of a neuronostatin receptor and our progress in establishing the physiological relevance of the peptide. (Source: Peptides)
Source: Peptides - June 27, 2015 Category: Biochemistry Source Type: research

[des-Arg1]-Proctolin: A novel NEP-like enzyme inhibitor identified in Tityus serrulatus venom
Publication date: Available online 6 June 2015 Source:Peptides Author(s): Bruno Duzzi , Daniela Cajado-Carvalho , Alexandre Kazuo Kuniyoshi , Roberto Tadashi Kodama , Fabio Cesar Gozzo , Mariana Fioramonte , Denise Vilarinho Tambourgi , Fernanda Vieira Portaro , Vanessa Rioli The scorpion Tityus serrulatus venom comprises a complex mixture of molecules that paralyzes and kills preys, especially insects. However, venom components also interact with molecules in humans, causing clinic envenomation. This cross-interaction may result from homologous molecular targets in mammalians and insects, such as (NEP)-like enzymes. In ...
Source: Peptides - June 27, 2015 Category: Biochemistry Source Type: research

Peptides: Basic determinants of reproductive functions
Publication date: Available online 12 June 2015 Source:Peptides Author(s): Onder Celik , Suleyman Aydin , Nilufer Celik , Musa Yilmaz Mammalian reproduction is a costly process in terms of energy consumption. The critical information regarding metabolic status is signaled to the hypothalamus mainly through peripheral peptides from the adipose tissue and gastrointestinal tract. Changes in energy stores produce fluctuations in leptin, insulin, ghrelin and glucose signals that feedback mainly to the hypothalamus to regulate metabolism and fertility. In near future, possible effects of the nutritional status on GnRH regulati...
Source: Peptides - June 27, 2015 Category: Biochemistry Source Type: research

Kbot55, purified from Buthus occitanus tunetanus venom, represents the first member of a novel α-KTx subfamily
In this study, Kbot55 has been subjected to a screening on ion channels expressed in Xenopus laevis oocytes. It was found that Kbot55 targets voltage-gated potassium channels with high affinity. Kbot55 shows very low amino acid identity with other scorpion potassium toxins and therefore was considered a bona fide novel type of scorpion toxin. Sequence alignment analysis indicated that Kbot55 is the first representative of the new α-Ktx31 subfamily and therefore was classified as α-Ktx31.1. (Source: Peptides)
Source: Peptides - June 27, 2015 Category: Biochemistry Source Type: research

An overview of antifungal peptides derived from insect
Publication date: Available online 18 June 2015 Source:Peptides Author(s): Mohammad Omer Faruck , Faridah Yusof , Silvia Chowdhury Fungi are not classified as plants or animals. They resemble plants in many ways but do not produce chlorophyll or make their own food photosynthetically like plants. Fungi are useful for the production of beer, bread, medicine, etc. More complex than viruses or bacteria; fungi can be destructive human pathogens responsible for various diseases in humans. Most people have a strong natural immunity against fungal infection. However, fungi can cause diseases when this immunity breaks down. In t...
Source: Peptides - June 27, 2015 Category: Biochemistry Source Type: research

From blood to brain through BBB and astrocytic signaling
Publication date: Available online 22 June 2015 Source:Peptides Author(s): Weihong Pan In this Festschrift, I discuss the career and guiding principles to which Abba J. Kastin has adhered during the last 20 years we worked together. I briefly describe the history of our joint laboratory group, the context of studies of peptide permeation across the blood–brain barrier (BBB), and newer developments in the BBB Group as Abba steps down after serving 35 years as the founding Editor-in-Chief for Peptides. Abba's BBB studies on peptides have contributed to concepts in the neuroendocrinology of feeding and developed infor...
Source: Peptides - June 27, 2015 Category: Biochemistry Source Type: research

Nesfatin-1 – More than a food intake regulatory peptide
Publication date: Available online 25 June 2015 Source:Peptides Author(s): Andreas Stengel Nesfatin-1 was discovered a decade ago and despite the fact that it represents just one of a multitude of food intake-inhibiting factors it received increasing attention. This led to a detailed characterization of NUCB2/nesfatin-1's physiological property to reduce food intake and also gave rise to an involvement in the long term regulation of body weight, especially under conditions of obesity. In addition, studies indicated the involvement of NUCB2/nesfatin-1 in other homeostatic functions as well: glucose homeostasis, water inta...
Source: Peptides - June 27, 2015 Category: Biochemistry Source Type: research

Isolation and characterization of Ts19 Fragment II, a new long-chain potassium channel toxin from Tityus serrulatus venom
Publication date: Available online 25 June 2015 Source:Peptides Author(s): Felipe Augusto Cerni , Manuela Berto Pucca , Fernanda Gobbi Amorim , Karla de Castro Figueiredo Bordon , Julien Echterbille , Loïc Quinton , Edwin De Pauw , Steve Peigneur , Jan Tytgat , Eliane Candiani Arantes Ts19 Fragment II (Ts19 Frag-II) was first isolated from the venom of the scorpion Tityus serrulatus (Ts). It is a protein presenting 49 amino acid residues, three disulfide bridges, M r 5534Da and was classified as a new member of class (subfamily) 2 of the β-KTxs, the second one described for Ts scorpion. The β-KTx family is...
Source: Peptides - June 27, 2015 Category: Biochemistry Source Type: research

In vitro ACE-inhibitory peptide KGYGGVSLPEW facilitates noradrenaline release from sympathetic nerve terminals: Relationship with the lack of antihypertensive effect on spontaneous hypertensive rats
This study aimed to validate the antihypertensive activity of the angiotensin-converting enzyme (ACE)-inhibitor whey protein hydrolysate (WPH) obtained through the action of proteolytic enzymes from Cynara Cardunculus. The antihypertensive activity of WPH fractions containing peptides with molecular weight below 3kDa (Whey<3kDa) and 1kDa (Whey<1kDa) along with the antihypertensive activity of three potent ACE-inhibitory peptide sequences (DKVGINYW, DAQSAPLRVY and KGYGGVSLPEW), previously identified in WPH, were also investigated. In parallel, the influence of KGYGGVSLPEW (the most potent ACE-inhibitory peptid...
Source: Peptides - June 27, 2015 Category: Biochemistry Source Type: research

Glucagon and GLP–1 exhibit no synergistic enhancement of glucose–stimulated insulin secretion in mice
We examined whether complementary action of the two hormones also exist on insulin secretion. Female C57BL/6 mice were injected intravenously with glucose with or without GLP–1, glucagon or the combination of GLP-1 and glucagon at three different dose levels. Furthermore, freshly isolated mouse islets were incubated for 30min in with the presence of 2.8, 11.1 or 16.7mmol/l glucose or with 11.1mmol/l glucose in the presence of 100 nmol/l glucagon and/or GLP–1. It was found that at 1min after glucose injection alone, insulin rose to a peak level and this peak, as well as the 50min area under the insulin curve (AU...
Source: Peptides - June 27, 2015 Category: Biochemistry Source Type: research