Novel antimicrobial peptides from the venom of the eusocial bee Halictus sexcinctus (Hymenoptera: Halictidae) and their analogs
Abstract
Two novel antimicrobial peptides Gly-Met-Trp-Ser-Lys-Ile-Leu-Gly-His-Leu-Ile-Arg-NH2 (HAL-1) and Gly-Lys-Trp-Met-Ser-Leu-Leu-Lys-His-Ile-Leu-Lys-NH2 (HAL-2) designated halictines were identified in the venom of the wild bee Halictus sexcinctus. They possess high antimicrobial activity against both Gram-positive and -negative bacteria and noticeable hemolytic activity.
As indicated by CD and NMR spectroscopy, halictines can adopt an amphipathic aplha-helical secondary structure in an anisotropic environment such as the bacterial cell membrane. Altogether we prepared 51 of HAL-1 and HAL-2 analogs to study the effect of such structural parameters as cationicity, hydrophobicity, alpha-helicity, amphipathicity, and truncation on antimicrobial and hemolytic activities.