What is "cecropin"

n. (context protein English) Any of a group of antimicrobial peptides that lyse bacterial cell membranes

Cecropins are antimicrobial peptides. They were first isolated from the hemolymph of Hyalophora cecropia, whence the term cecropin was derived. Cecropins lyse bacterial cell membranes; they also inhibit proline uptake and cause leaky membranes.

Cecropins constitute a main part of the cell-free immunity of insects. Cecropins are small proteins of about 31 - 37 amino acid residues active against both Gram-positive and Gram-negative bacteria. Cecropins isolated from insects other than Hyalophora cecropia (Cecropia moth) have been given various names; bactericidin, lepidopterin, sarcotoxin, etc. All of these peptides are structurally related.