<biochemistry> Family of small (30-35 residue) cysteine rich cationic proteins found in vertebrate phagocytes (notably the azurophil granules of neutrophils) and active against bacteria, fungi and enveloped viruses.

May constitute up to 5% of the total protein. Insect defensins have some sequence homology with the vertebrate forms.

This entry appears with permission from the Dictionary of Cell and Molecular Biology

(11 Mar 2008)