This is a cysteine-rich domain found at the C-terminal end of alpha and beta defensins mainly from mammals that lyse bacteria, fungi and enveloped viruses by forming multimeric membrane-spanning channels.

Defensins are 2-6kDa, cationic, microbicidal peptides active against many Gram-negative and Gram-positive bacteria, fungi, and enveloped viruses [ PUBMED:8528769 … expand

This is a cysteine-rich domain found at the C-terminal end of alpha and beta defensins mainly from mammals that lyse bacteria, fungi and enveloped viruses by forming multimeric membrane-spanning channels.

Defensins are 2-6kDa, cationic, microbicidal peptides active against many Gram-negative and Gram-positive bacteria, fungi, and enveloped viruses [ PUBMED:8528769 ], containing three pairs of intramolecular disulphide bonds. On the basis of their size and pattern of disulphide bonding, mammalian defensins are classified into alpha, beta and theta categories. Alpha-defensins, which have been identified in humans, monkeys and several rodent species, are particularly abundant in neutrophils, certain macrophage populations and Paneth cells of the small intestine. Every mammalian species explored thus far has beta-defensins. In cows, as many as 13 beta-defensins exist in neutrophils. However, in other species, beta-defensins are more often produced by epithelial cells lining various organs (e.g. the epidermis, bronchial tree and genitourinary tract). Theta-defensins are cyclic and have so far only been identified in primate phagocytes.

Neutrophil alpha-defensin has antimicrobial activity against Gram-negative bacteria, and to a lesser extent also against Gram-positive bacteria and fungi. It also protects blood cells against infection with HIV-1 (in vitro) and inhibits corticotropin (ACTH)-stimulated corticosterone production [ PUBMED:15616305 PUBMED:15620707 ].