Hepatopancreatic Proteins of Snow Crab and Red King Crab with Antibacterial Activity

Troughout their long history, crustaceans, despite lacking a highly specific vertebrate-like adaptive immune system, have successfully adapted to living within their environment rich in microorganisms, in part due to the presence of antimicrobial peptides. One valuable source of antimicrobial peptides is hepatopancreas, a waste product from crab fishery and its processing. Data from zymogram and 1H NMR spectra showed that the extract of snow crab hepatopancreas contains a small peptide (about 3 kDa) that hydrolyzes the cell wall and the cell wall polysaccharide of M. lysodeikticus. The discovered peptide may be of interest for practical application. A protein (about 14 kDa), isolated from the red king crab hepatopancreas using affinity chromatography on heparin-Sepharose, is also active against the cell wall of the gram-positive bacterium M. lysodeikticus, as it was demonstrated with zymography and turbidimetric methods.