The horseshoe crab peptide polyphemusin I possesses high antimicrobial activity, but its mechanism of action is as yet not well defined. Using a biotin-labeled polyphemusin I analogue and confocal fluorescence microscopy, we showed that the peptide accumulates in the cytoplasm of wild-type Escherichia coli within 30 min after addition without causing substantial membrane damage.

l-2,5-Dihydrophenylalanine is extensively incorporated as a phenylalanine analogue into cell proteins. Phenylalanine-requiring Escherichia coli ATCC 9723f and sarcoma 180 grow at normal rates initially with the analogue and maximally replace 65 and 33%, respectively, of phenylalanine in the peptide residues of their cell protein without death. With the analogue alone growth of E. coli becomes n...

7-Azatryptophan and 2,7-diazatryptophan are sensitive to polarity changes and water content, respectively, and should be ideal for studying protein-protein and protein-peptide interactions. In this study, we replaced the tryptophan in peptide Baa (LKWKKLLKLLKKLLKLG-NH2) with 7-azatryptophan or 2,7-diazatryptophan, forming (7-aza)Trp-Baa and (2,7-aza)Trp-Baa, to study the calmodulin (CaM)-peptid...

Background. One of the perspectives anticytokine therapy is development synthetic oligopeptides, which can bind and inhibit activity cytokines. The peptide, a structural analogue cytokine-binding region chemokine receptor, interest as ligand for interaction with interleukin-8 (IL-8). aim research was to evaluate Trp-Asp-Phe-Asp IL-8. Material methods. between peptide cytokine evaluated by chang...

A cardiolipin- and protease-activated protein kinase (PAK) has been isolated from cytoplasmic extracts of rat liver. The enzyme (PAK-1) phosphorylates the ribosomal protein S6-(229-239) peptide analogue and can be activated by limited proteolysis. Partial amino acid sequences of tryptic peptides derived from both the purified 116-kDa PAK-1 holoenzyme and its active catalytic fragment reveal tha...

As part of an effort to develop new, low molecular mass peptide antibiotics, we searched for the shortest bioactive analogue of gaegurin 5 (GGN5), a 24-residue antimicrobial peptide. Thirty-one kinds of GGN5 analogues were synthesized, and their biological activities were analyzed against diverse microorganisms and human erythrocytes. The structural properties of the peptides in various solutio...