Defensin Alpha 1, Neutrophil (DEFa1)

Defensins are cytotoxic peptides and have a well-defined role in host defense. Defensins are a family of microbicidal and cytotoxic peptides thought to be involved in host defense. They are abundant in the granules of neutrophils and also found in the epithelia of mucosal surfaces such as those of the intestine, respiratory tract, urinary tract, and vagina. Members of the defensin family are highly similar in protein sequence and distinguished by a conserved cysteine motif. Several alpha defensin genes appear to be clustered on chromosome 8.

The defensin, alpha 1 protein, is found in the microbicidal granules of neutrophils and likely plays a role in phagocyte-mediated host defense. It differs from defensin, alpha 3 by only one amino acid.