Purification and cDNA cloning of a novel antibacterial peptide with a cysteine-stabilized alpha beta motif from the longicorn beetle, Acalolepta luxuriosa

摘要

An antibacterial peptide from the hemolymph of a coleopteran insect, Acalolepta luxuriosa, in the superfamily Cerambyocidea was characterized. The mature antibacterial peptide had 27 amino acid residues with a theoretical molecular weight of 3099.29 and it showed antibacterial activity against Escherichia coli and Micrococcus luteus. The deduced amino acid sequence of the peptide showed that it had a cysteine-stabilized alphabeta motif with a (CCXXXCCCXC)-C-. . .-C-. . .-C-. . . consensus sequence, like insect defensins. However, the results of a multiple sequence alignment and phylogenetic analysis with CLUSTAL X indicated that this peptide is a novel peptide with a cysteine-stabilized alphabeta motif that is distant from insect defensins. (C) 2003 Elsevier Ltd. All rights reserved. [References: 38]