Isolation And Purification Of The Peptides From Apostichopus Japonicus And Evaluation Of Its Antibacterial And Antitumor Activities

The Apostichopus Japonicus is an economically important marine species found in the Pacific and Indian Ocean. Since1980’s, seed rearing techniques of several commercial species have been successively established in Japan, China and India. Sea cucumbers possess high nutritional and medical value as they are abundant in mucopolysaccharide and proteins. Because of this reason, they are rapidly became a favored aquaculture species in Shandong and Liaoning Provinces.In the present article, peptides were isolated and purified from enteron of the Apostichopus japonicus by methanol and gel filtration chromatography. The antibacterial activities test and antitumor activities in vitro was carried out by the disk diffusion method and MTT assay. The minimal inhibitory concentration (MIC) of the antimicrobial peptides to Escherichia coli, Staphylococcus aureus, Vibrio harveyi, Bibrio Parahemolyticus, Bacillus subti, Micrococcus lysodeikticus, Edwardsiella tarda and Vibrio anguillarum were analyzed by means of a MTT assay. In addition, the antimicrobial peptides were analyzed by SDS-PAGE and high-performance liquid chromatography (HPLC).The study proves that three compositions are obtained by experimentation, which is classified as A1, A2and A3. A3is provided with obvious effect to inhibit these bacteria and the cancer cells. The MIC to Micrococcus lysodeikticus, Bibrio Parahemolyticus, Escherichia coli, Staphylococcus aureus, Vibrio harveyi, Edwardsiella tarda, Vibrio anguillarum and Bacillus subti was0.5mg/ml,1.0mg/ml,1.0mg/ml,1.0mg/ml,2.0mg/ml,2.0mg/ml,2.0mg/ml and4.0mg/ml respectively. The proliferation effect of antimicrobial peptides on A549cell is clearly demonstrated. The SDS-PAGE indicates that the molecular weight of A3is about6.5KD and the HPLC illustrates the composition of A3is complex, four components are shown in the figure of HPLC.The functions of antimicrobial peptides were studied in this experimentation, it is true that the antimicrobial peptide, A3, has a broad spectrum of antimicrobial activities both against Gram-positive and Gram-negative bacteria. In this study, the antimicrobial peptide, A3, showed significant inhibition of cell proliferation on lung cancer cells A549in a dose-dependent manner. Thus, antimicrobial peptide research may be useful to the development of a new class of antibacterial and antitumor drugs. Recently, a large number of antibiotics have been consumed and thus bacterial resistance to common antibiotics is becoming more serious. In order to avoid bacterial resistance, we need to produce the antimicrobial peptides to replace antibiotics. Apostichopus Japonicus farming has developed rapidly in recent years, however, the rapid development and poor operation resulted in many problems such as the occurrence of diseases. For this reason, the antimicrobial peptides were isolated and purified from enteron of Apostichopus japonicus to resist diseases in commercial farming.