A metal ion that attaches to a peptide backbone has the choice of binding to an amide carbonyl oxygen atom or to an amide nitrogen atom by replacement of the amide proton. Coordination to the nitrogen atom is normally accompanied by elimination of the proton, thereby resulting in deprotonation of the ligand. An alternative possibility, not involving deprotonation, is the unusual amide/iminol ta...

A new biological active hexapeptide of C-terminal of nocistatin, contains Glu-Gln-Lys-Gln-Leu-Gln sequence was synthesized according to solid phase peptide synthesis on the surface of 2-chloro tritylchloride resin and using fmoc-protected amino acids in the presence of TBTU (O-(Benzotriazol-1-yl)-N,N,N',N'-tetramethyl uranium tetrafluoroborate) as a coupling reagent. Then, amidation of the C-te...

Alanine tripeptide is a good model molecule to analyze a conformational distribution of an unstructured peptide backbone, to study a competition between the intraand intermolecular hydrogen-bonding, as well as the favourable solvation conditions. In our work, we used three different spectroscopic techniques, the Raman and infrared (IR) spectroscopy, and the vibrational circular dichroism (VCD) ...

This study deals with the interaction of polypeptide hormones with their receptors. Specifically it involves the binding of synthetic ACTH analogs and fragments to a particulate fraction from beef adrenal cortical tissue. This fraction was found to bind synthetic [(14)C-Phe] [Gln(5)]beta-corticotropin(1-20) amide but failed to bind significant amounts of [(14)C-Phe] [Gln(5)]beta-corticotropin(1...

COMMUNICATION Daniel Harries et al. Enthalpically driven peptide stabilization by protective osmolytes FEATURE ARTICLE Liu-Zhu Gong et al. The role of double hydrogen bonds in asymmetric direct aldol reactions catalyzed by amino amide derivatives

The widely expressed dipeptidyl peptidase-4 enzyme rapidly cleaves the gut hormone glucagon-like peptide-1 [GLP-1(7-36)amide] at the N terminus to generate GLP-1(9-36)amide. Both intact GLP-1(7-36)amide and GLP-1(9-36)amide exert cardioprotective actions in rodent hearts; however, the mechanisms underlying the actions of GLP-1(9-36)amide remain poorly understood. We used mass spectrometry of co...

Introduction: Arginine-phenylalanine-amide-related peptide-3 (RFRP-3) and kisspeptin are believed to be inhibitor and stimulator of gonadotropin releasing hormone (GnRH) secretion, respectively. The aim of the present study was to compare the effect of lactation on the expression of RFRP-3 mRNA in dorsomedial hypothalamic nucleus (DMH) and KiSS-1 mRNA in arcuate nucleus (ARC) of hypothalamus...

Objective An abnormality in pulse amplitude and frequency of gonadotropin releasing hormone (GnRH) secretion is the most characteristics of polycystic ovarian syndrome (PCOS). On the other hand, arginine-phenylalanine-amide (RFamide)-related peptide-3 (RFRP3) inhibits the secretion of GnRH in mammalian hypothalamus. Therefore, the current study evaluated the expression of RFRP3 mRNA in dorsomed...

Background: Dilated cardiomyopathy (DCM) is revealed with the left ventricular dilatation and systolic dysfunction. This study was performed to determine the level of Calcitonin Gene Related Peptide (CGRP) and Brain Natriuretic Peptide (BNP) in children with dilated cardiomyopathy and controls and comparison of these two biomarkers in patients. Materials and Methods: This case-control study was...

Conformational properties of a 12-residue tryptophan zipper (trpzip) beta-hairpin peptide (AWAWENGKWAWK-NH(2), a modification of the original trpzip2 sequence) are analyzed under equilibrium conditions using ECD and IR spectra of a series of variants, singly and doubly C(1)-labeled with (13)C on the amide CO. The characteristic features of the (13)CO component of the amide I' IR band and their ...