Abstract
Peptides were isolated and purified from enteron of the Apostichopus japonicus (A. japonicus) by methanol and gel filtration chromatography. The antibacterial activity test in vitro was carried out by the agar diffusion method. The minimal inhibitory concentration (MIC) of the antimicrobial peptides to Escherichia coli (E. coli), Staphylococcus aureus (Sa), Vibrio harveyi (Vh), Vibrio parahemolyticus (Vp), Bacillus subtilis (Bs), Micrococcus lysodeikticus (Ml), Edwardsiella tarda (Et) and Vibrio anguillarum (Va) were analyzed by means of an MTT assay. The antimicrobial peptides were also analyzed by SDS-PAGE and high-performance liquid chromatography (HPLC). Antitumor activities were researched by an MTT assay as well. Three compositions are obtained by experimentation that is classified as A1, A2 and A3. A3 inhibits the bacteria and the cancer cells. The MIC to Ml, Vp, E. coli, Sa, Vh, Et, Va and Bs was 0.5, 1.0, 1.0, 1.0, 2.0, 2.0, 2.0 and 4.0 mg/ml, respectively. The proliferation effect of antimicrobial peptides on A549 cell is demonstrated. The SDS-PAGE indicates that the molecular weight of A3 is about 6.5 kD. The HPLC figure illustrates that the composition of A3 is complex with four components shown.
Key words: Apostichopus japonicas, antimicrobial peptides, antibacterial activities, sodium dodecyl sulfate polyacrylamide gel electrophoresis, minimal inhibitory concentration.
