Defensins

Title: Defensins
CAS Registry Number: 103220-14-0
Literature References: A class of low molecular weight cationic peptides which have in vitro microbiocidal activity against various bacteria, fungi, and viruses, originally isolated from mammalian neutrophils. Possess similar arginine-rich, cysteine-rich structures of 29-35 amino acids with a conserved core of 8-11 residues. Characterized by six cysteines comprising 3 disulfide linkages. Abbreviated NP (neutrophil peptide) where NP is used for rabbit, HNP for human, GPNP for guinea pig etc.; defensins represent a major protein component of granulocytes. Initial identification studies: H. I. Zeya, J. K. Spitznagel, Science 142, 1085 (1961); eidem, J. Bacteriol. 91, 750 (1966). Isoln, antimicrobial activities and amino acid sequence of six NPs: M. E. Selsted et al., Infect. Immun. 45, 150 (1984); M. E. Selsted et al., J. Biol. Chem. 260, 4579 (1985); of three HNPs: T. Ganz et al., J. Clin. Invest. 76, 1427 (1985); M. E. Selsted et al., ibid. 1436. Crystal structure of HNP-3: C. P. Hill et al., Science 251, 1481 (1991). Direct inactivation of enveloped viruses: K. A. Daher et al., J. Virol. 60, 1068 (1986). In vitro cytolysis of tumor cells: A. Lichtenstein et al., Blood 68, 1407 (1986). Mechanism of cytolysis: eidem, J. Immunol. 140, 2686 (1988). Identification and isoln of insect defensins from haemolymph of dipteran: J. A. Hoffmann, D. Hoffmann, Res. Immunol. 141, 910 (1990). Structure determn of insect forms: P. Lepage et al., Eur. J. Biochem. 196, 735 (1991). Review of insect forms: J. A. Hoffmann, C. Hetru, Immunol. Today 13, 411-415 (1992). Review: B. L. Kagan et al., Toxicology 87, 131-149 (1994); including insect forms: T. Ganz, R. I. Lehrer, Pharmacol. Ther. 66, 191-205 (1995).
Deferasirox Deferiprone Defibrotide Deflazacort Defosfamide

Monomeric and dimeric structures of human beta-defensin HBD-2

Defensins are small cysteine-rich cationic proteins found in both vertebrates and invertebrates. They have also been reported in plants.[1][2] They are, and function as, host defense peptides. They are active against bacteria, fungi and many enveloped and nonenveloped viruses. They consist of 18-45 amino acids including six (in vertebrates) to eight conserved cysteine residues. Cells of the immune system contain these peptides to assist in killing phagocytosed bacteria, for example in neutrophil granulocytes and almost all epithelial cells. Most defensins function by binding to the microbial cell membrane, and, once embedded, forming pore-like membrane defects that allow efflux of essential ions and nutrients.