Learn More
Defensins are antimicrobial and cytotoxic peptides that contain 29-35 amino acid residues, including six invariant cysteines whose intramolecular disulfide bonds cyclize and stabilize them in a complexly folded, triple-stranded beta-sheet configuration. Generated by the proteolytic processing of 93-95 amino acid precursor peptides, the constitute > 5% of(More)
Human neutrophils contain two structurally distinct types of antimicrobial peptides, beta-sheet defensins (HNP-1 to HNP-4) and the alpha-helical peptide LL-37. We used radial diffusion assays and an improved National Committee for Clinical Laboratory Standards-type broth microdilution assay to compare the antimicrobial properties of LL-37, HNP-1, and(More)
Defensins are small, cysteine-rich antimicrobial peptides that are abundant in human, rabbit, and guinea pig neutrophils (PMN). Three defensins (human neutrophil peptide defensin [HNP]-1, HNP-2, and HNP-3) constitute between 30 and 50% of the total protein in azurophil granules of human PMN. We examined the mechanism of HNP-mediated bactericidal activity(More)
Animals and higher plants express endogenous peptide antibiotics called defensins. These small cysteine-rich peptides are active against bacteria, fungi and viruses. Here we describe plectasin-the first defensin to be isolated from a fungus, the saprophytic ascomycete Pseudoplectania nigrella. Plectasin has primary, secondary and tertiary structures that(More)
During the past year, novel beta-defensins of mice and men have been identified, together with a novel defensin subfamily (the circular or 'theta' minidefensins) in primates. Insight into the evolution of defensins has been obtained from structural studies, and several mechanisms related to microbial resistance to defensins have been delineated. There is(More)
We compared the expression of human alpha- and beta-defensins by various human tissues. mRNA for alpha-defensins HNP1-3, abundant in bone marrow, was detected in peripheral blood leukocytes, spleen and thymus by RT-PCR, which revealed alpha-defensins HD5 and HD6 only in the small intestine. In contrast, the pancreas and kidney expressed high levels of hBD-1(More)
Gene-encoded peptide antibiotics are ubiquitous components of host defenses in mammals, birds, amphibia, insects, and plants. Their de novo synthesis or release from storage sites can be induced rapidly, which makes them particularly important in the initial phases of resistance to microbial invasion. The endogenous antimicrobial peptides of animals are(More)
Gallinacin-3 and gallopavin-1 (GPV-1) are newly characterized, epithelial beta-defensins of the chicken (Gallus gallus) and turkey (Meleagris gallopavo), respectively. In normal chickens, the expression of gallinacin-3 was especially prominent in the tongue, bursa of Fabricius, and trachea. It also occurred in other organs, including the skin, esophagus,(More)
We developed two sensitive methods for identifying antimicrobial molecules in leukocytes and other tissues. One method uses a gel overlay technique and was designed to identify antimicrobial polypeptides in samples subjected to polyacrylamide gel electrophoresis. The other, a radial diffusion assay, allows multiple fractions obtained by chromatographic(More)
Theta-defensins are circular octadecapeptides that contain an internal tridisulfide ladder. Because retrocyclin-1, an ancestral hominid theta-defensin, can protect human cells in vitro from infection by T- and M-tropic strains of HIV-1, we used surface plasmon resonance techniques to study its binding to glycoproteins and glycolipids implicated in HIV-1(More)