A comparative analysis was made on the influence of corticotropin oligopeptides on rabbits' behaviour under acute stress conditions, or after the electrostimulation of the Vmh. The 4-10 fragment and analogue of corticotropin and tripeptide Pro-Gly-Pro was administered icv to the rabbits. It was proved that the analogue and 4-10 fragment had a significant influence on modification of animals' be...

The effect of a selected tripeptide, Z-d-Phe-Phe-Arg(NO(2)) (SV-4814) on the kinetics of lysis of green monkey erythrocytes by measles virus hemolysin suggested conditions of competitive inhibition. SV-4814 prevented not only hemoglobin release, but also the preceding leakage of K(+) through the cell membrane. The capacity of 12 different dipeptides, 6 tripeptides, including SV-4814, and 4 tetr...

Peptides produced by the enzymatic degradation of collagens are reported to have various activities of biological and medical interest. The mechanisms underlying their actions are, however, poorly understood. We have produced, by collagenase digestion of type I collagen, a highly purified, non-antigenic, and low allergenic tripeptide fraction (collagen tripeptide, Ctp). We report here the effec...

Proteostasis is critical for the maintenance of life. In neuronal cells an imbalance between protein synthesis and degradation is thought to be involved in the pathogenesis of neurodegenerative diseases during aging. Partly, this seems to be due to a decrease in the activity of the ubiquitin-proteasome system, wherein the 20S/26S proteasome complexes catalyse the proteolytic step. We have chara...

The late stages of biosynthesis of phosphinothricin tripeptide (PTT) involve peptide formation and methylation on phosphorus. The exact timing of these transformations is not known. To provide insight into this question, we developed a heterologous expression system for PhsA, one of three NRPS proteins in PTT biosynthesis. The apparent k(cat)/K(m) value for ATP-pyrophosphate exchange activity f...

In this work we are trying to gain insight into the mechanisms of ion-protein interactions in aqueous media at the molecular scale through fully atomistic molecular dynamics simulations. We present a systematic molecular simulation study of interactions of sodium and halide ions with a trialanine peptide in aqueous sodium halide solutions with different salts concentrations (0.20, 0.50, 1.0 and...

Peptidomimetic inhibitors of the hepatitis C NS3 protease often exhibit poor biopharmaceutical properties. Structure modification of a substrate-based tripeptide into a b-strand 15-membered ring scaffold provided a new class of peptidomimetics that are significantly superior as drug candidates to their acyclic precursors. Tripeptide dienes composed of three unnatural amino acid residues with nu...

The pentapeptide moiety of uridine diphosphate acetylmuramyl-pentapeptide, a precursor of the peptidoglycan of bacterial cell walls, is synthesized in a reaction sequence involving five enzymes. The amount and specificity of these enzymes have been studied in 10 microorganisms, five of which contain L-lysine as the third amino acid in the peptide sequence, and five of which contain instead meso...