Peptides Of Biological Interest Research Articles

Chemoselective Disulfide Formation by Thiol-Disulfide Interchange in SIT-Protected Cysteinyl Peptides.

Chemoselective disulfide formation is accomplished through a thiol-disulfide interchange approach using sec-isoamyl mercaptan (SIT) as an alkyl sulfenyl-protecting group of one of the Cys residues involved in the pairing. SIT has a dual and unique characteristic, acting as a masking group during the synthesis and directing disulfide formation in the presence of a free thiol. This novel approach is illustrated by the synthesis of several peptides of biological interest.

Methylation of ethanolamine groups in phosphoethanolamines is relevant for L-arginine insertion in lipid membranes

The interaction of L-arginine with membranes composed by phospholipids with different degrees of methylation of the ethanolamine group was studied by means of surface and dipole potentials and surface pressure variations. The subsequent methylation of the amine head group appears to hinder the synergic response of the adsorption observed in phosphatidylethanolamine membranes. The kinetics of the binding process denotes that the methyl groups are relevant in regulating the specific interaction of the amino acid with the interface by hydrogen bonds. This response can be put in correlation with the function of signal transduction assigned previously to methyl lipids [F. Hirata and J. Axelrod, 1980] and appears to be relevant to understand the mechanism of insertion of arginine residues in peptides of biological interest.

Kernel energy method illustrated with peptides

AbstractWe describe a kernel energy method (KEM) for applying quantum crystallography to large molecules, with an emphasis on the calculation of the molecular energy of peptides. The computational difficulty of representing the system increases only modestly with the number of atoms. The calculations are carried out on modern parallel supercomputers. By adopting the approximation that a full biological molecule can be represented by smaller “kernels” of atoms, the calculations are greatly simplified. Moreover, collections of kernels are, from a computational point of view, well suited for parallel computation. The result is a modest increase in computational time as the number of atoms increases, while retaining the ab initio character of the calculations. We describe a test of our method, and establish its accuracy using 15 different peptides of biological interest. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005

New α-Amino Acids for Peptides of Biological Interest: 2-[2′-(Methylthio)Ethyl]Methionine Derivatives

Abstract Synthetic route to N- and C-protected derivatives of the new α,α-disubstituted achiral methionine analogue 2-[2′-(methylthio)ethyl]methionine is described starting from diethyl bis(2-methylthioethyl)malonate.

O-Benzotriazolyl-N,N,N′,N′-tetramethyluronium Hexafluorophosphate as Coupling Reagent for the Synthesis of Peptides of Biological Interest

<i>O</i>-Benzotriazolyl-<i>N</i>,<i>N</i>,<i>N</i>′,<i>N</i>′-tetramethyluronium Hexafluorophosphate as Coupling Reagent for the Synthesis of Peptides of Biological Interest

Microsequence analysis of peptides and proteins: IV. Structural studies on human leukocyte interferons

The sequence of the tryptic peptides of three major species of human leukocyte interferon was determined by microsequencing procedures. The peptides were aligned by comparison with the amino acid sequences predicted by the DNA sequences of recombinants containing leukocyte interferon-coding inserts. In addition, extended NH 2-terminal amino acid sequences of two human leukocyte interferons produced in Escherichia coli by recombinant DNA methodology are also reported. This report demonstrates application of microsequencing methodology to low nanomole and subnanomole amounts of proteins and peptides of biological interest.