大黄鱼（Pseudosciaena crocea）一种新型抗菌肽的纯化及其生物学特性研究

摘要

以致病性溶藻弧菌为指示菌，通过酸粗提、固相萃取、Sephadex G-25柱凝胶层析和RP—HPLC等分离纯化技术，从大黄鱼胃肠组织中分离纯化抗菌肽。结果表明，大黄鱼肠道组织中存在着多种抗菌物质，并最终得到一种高纯度的新型抗菌肽AMP-W3。AMP—W3由10种氨基酸组成，其中天冬氨酸、谷氨酸和甘氨酸的含量较高。AMP-W3对溶藻弧菌的最低抑菌浓度介于1．25—2．5μg／ml，对人血红细胞的溶血浓度为1．25μg／ml，在酸性条件下的抗菌活性更强，对革兰氏阳性细菌，革兰氏阴性细菌以及真菌表现出广谱的抗菌活性。本文是首次从鱼类胃肠组织中分离得到抗菌肽，有助于更全面了解鱼类的抗菌肽及抗感染免疫。%The purpose of this study was to obtain antimicrobial peptide from the gastrointestinal tract of Pseudosciaena crocea. Our results showed that a novel antimicrobial peptide to Vibrio alginolyticus was isolated and purified using acid extraction, solid phase extraction, Sephadex G25 and reverse phase high performance liquid chromatography. The antimicrobial peptide, which was named AMP-W3, contained 10 different amino acids and was enriched in Glu, Gly and Asp. Minimal inhibition concentrations of the peptide were at 1.25-2.5μg/ml. Moreover, AMP-W3 were hemolytic for human red blood cells when its concentration was higher than 1.25μg/ml. In the acid condition, this peptide showed higher antimicrobial activity than in the alkaline solution, and displayed a broad spectrum of antimicrobial activity against Gram-negative, Gram-positive bacteria and fungi, including Escherichia coli, Staphylococcus aureus and Aspergillus niger, etc. This is the first time that an antimicrobial peptide was isolated from the gastrointestinal tract of fish, and it may help us to understand antimicrobial peptides and the innate anti-infective defense system of fish.