Recently a number of endogenous host defence molecules with antimicrobial activity have been identified in mammals, invertebrates and amphibians (for reviews see Ganz, Selsted Within this group of anti-microbial agents there are several small peptides (2-4K.) that include the defensins (found predominantly in mammalian phago-cytes), cecropins, diptericins, attacins, apidae-cins, abaecin, royali...

abstract         background and objective: lactic acid bacteria are gram-positive, catalase-negative, nonsporulating, either rod- or coccus-shaped bacteria that have beneficial effects on their hosts by producing antimicrobial substances such as lactic acid, hydrogen peroxide, bacteriocins and biosurfactants. bacteriocins are antimicrobial peptides that are produced by bacteria and can inhibit ...

Magainin and PGLa are 23- and 21-residue peptides isolated from the skin of the African clawed frog Xenopus laevis. They protect the frog from infection and exhibit a broad-spectrum antimicrobial activity in vitro. The mechanism of this activity involves the interaction of magainin with microbial membranes. We have measured the secondary structure and membrane-perturbing ability of these peptid...

The antimicrobial peptides magainin 2, indolicidin, and temporins B and L were found to modulate the hydrolytic activity of secretory phospholipase A(2) (sPLA(2)) from bee venom and in human lacrimal fluid. More specifically, hydrolysis of phosphatidylcholine (PC) liposomes by bee venom sPLA(2) at 10 micro M Ca(2+) was attenuated by these peptides while augmented product formation was observed ...

Two novel antimicrobial peptides have been identified and characterized from venom of the African scorpion Pandinus imperator. The peptides, designated pandinin 1 and 2, are alpha-helical polycationic peptides, with pandinin 1 belonging to the group of antibacterial peptides previously described from scorpions, frogs and insects, and pandinin 2 to the group of short magainin-type helical peptid...

We study the interaction of antimicrobial peptides with lipopolysaccharide (LPS) bilayers to understand how antimicrobial peptides interact with the LPS monolayer on the outer membrane of Gram-negative bacteria. LPS in water spontaneously forms a multilamellar structure composed of symmetric bilayers. We performed X-ray lamellar diffraction and wide-angle in-plane scattering to study the physic...

Various mechanisms to fend off microbial invaders have been devised by a11 living organisms, including microorganisms themselves. The most sophisticated of these mechanisms relies on the synthesis of immunoglobulins directed against specific microbial targets. However, immunoglobulin-based immunity operates only in a relatively minor subset of living species, namely the higher vertebrates. A mu...

BACKGROUND The HE2 gene encodes a group of isoforms with similarities to the antimicrobial beta-defensins. We demonstrated earlier that the antimicrobial activity of HE2 proteins and peptides is salt resistant and structure dependent and involves permeabilization of bacterial membranes. In this study, we further characterize the antimicrobial properties of HE2 peptides in terms of the structura...

The dermaseptin antimicrobial peptide family contains members of 27-34 amino acids in length that have been predominantly isolated from the skins/skin secretions of phyllomedusine leaf frogs. By use of a degenerate primer in Rapid amplification of cDNA ends (RACE) PCR designed to a common conserved domain within the 5'-untranslated regions of previously-characterized dermaseptin encoding cDNAs,...