Cationic synthetic peptides: assessment of their antimicrobial potency in liquid preserved boar semen.

Various semen extender formulas are in use to maintain sperm longevity and quality whilst acting against bacterial contamination in liquid sperm preservation. Aminoglycosides are commonly supplemented to aid in the control of bacteria. As bacterial resistance is increasing worldwide, antimicrobial peptides (AMPs) received lively interest as alternatives to overcome multi-drug resistant bacteria.

Effects of cationic antimicrobial peptides on liquid-preserved boar spermatozoa.

Antibiotics are mandatory additives in semen extenders to control bacterial contamination. The worldwide increase in resistance to conventional antibiotics requires the search for alternatives not only for animal artificial insemination industries, but also for veterinary and human medicine. Cationic antimicrobial peptides are of interest as a novel class of antimicrobial additives for boar semen preservation.

Cyclic antimicrobial R-, W-rich peptides: the role of peptide structure and E. coli outer and inner membranes in activity and the mode of action.

This study compares the effect of cyclic R-, W-rich peptides with variations in amino acid sequences and sizes from 5 to 12 residues upon Gram negative and Gram positive bacteria as well as outer membrane-deficient and LPS mutant Escherichia coli (E. coli) strains to analyze the structural determinants of peptide activity. Cyclo-RRRWFW (c-WFW) was the most active and E.

The interaction of arginine- and tryptophan-rich cyclic hexapeptides with Escherichia coli membranes.

Cyclization of R- and W-rich hexapeptides has been found to enhance specifically the antimicrobial activity against Gram-negative Escherichia coli. To gain insight into the role of the bacterial outer membrane in mediating selectivity, we assayed the activity of cyclic hexapeptides derived from the parent sequence c-(RRWWRF) against several E. coli strains and Bacillus subtilis, L-form bacteria, and E.

Subproteomic analysis of metal-interacting proteins in human B cells.

Metal-protein interactions are vitally important in all living organisms. Metalloproteins, including structural proteins and metabolic enzymes, participate in energy transfer and redox reactions or act as metallochaperones in metal trafficking. Among metal-associated diseases, T cell mediated allergy to nickel (Ni) represents the most common form of human contact hypersensitivity.

T cell receptor (TCR) interaction with haptens: metal ions as non-classical haptens.

Haptens are classified as low molecular chemicals with an intrinsic potential to covalently modify proteins, and many of them are strong inducers of contact hypersensitivity (CHS). CHS is T cell mediated, and hapten-specific T cells have been shown to interact with hapten-modified, MHC-associated peptides. However, the most common contact sensitizer in the industrialized world is nickel.