Proteins of the Hepatopancreas of the Snow Crab and Red King Crab with Antibacterial Activity

During their long existence, crustaceans, despite the absence of a highly specific adaptive immune system, like vertebrates, have successfully adapted to survive in their natural habitat that is rich in microorganisms, in particular, due to antimicrobial peptides. One valuable source of antimicrobial peptides is the hepatopancreas (HPC), which is a waste product of crab fishing and processing. Using the method of zymography and ¹H-NMR spectroscopy we found that an extract from the hepatopancreas of the snow crab contains a small peptide (about 3 kDa) that hydrolyzes the cell wall and polysaccharide of the cell wall of M. lysodeikticus. This peptide may be of interest for practical use. A protein (about 14 kDa) was isolated from the hepatopancreas of the Red king crab using heparin–sepharose chromatography, which also exhibits activity against the cell wall of the gram-positive bacterium M. lysodeikticus, as was shown by zymography and turbidimetry.