诱导和非诱导条件下喙尾琵甲幼虫抗菌肽分离及抑菌活性比较

摘要

Antimicrobial peptide which plays a key role in the innate immune system of insect, is a kind of cationic alkaline peptide with low molecule weight. It is so effective against bacteria that it can be expected to develop as a new antibiotic. In this study, the authors compared the inhibitory effect of antimicrobial peptides of Blaps rhynchoptera Fainnaire larvae at induced treatment with non-induced treatment during isolation and purification procedures. The result indicated that both crude extracts of the two groups had no inhibitory effect on indicator bacteria at first. But after gel chromatography, the fraction DZP1 from non-induced group showed anti-bacteria activities against Staphylococcus aureus and Bacillus sublilis. Meanwhile the fraction YDP1 from induced group displayed anti-bacteria activities against Staphylococcus aureus, Bacillus subtilis and Pseudomonas aeruginosa. Moreover, YDP1 had stronger activity than DZP1 and its anti-bacteria spectrum was broadened. Based on the analysis of Tricine-SDS-PAGE, the components of DZP1 and YDP1 were similar, both composed of small peptides no less than 20 kD. The results suggested that the antimicrobial peptide could be' obtained from both induced and non-induced insects and the inhibitory effect against microbes would be stronger after challenging with bacteria.%对混合菌液诱导和非诱导处理的喙尾琵甲幼虫抗菌肽进行了分离纯化及抑菌活性比较.结果显示:诱导组和非诱导组粗提物无抑菌活性,但是经凝胶色谱分离后,从非诱导组获得组分DZP1,对金黄色葡萄球菌、枯草芽孢杆菌表现出抑制作用；从诱导组获得组分YDP1,对金黄色葡萄球菌、枯草芽孢杆菌、绿脓杆菌具有活性,且YDP1活性明显强于DZP1；Tricine-SDS-PAGE检测表明DZP1和YDP1组成、种类基本一致,主要由20 kD以下分子量的小肽组成.研究结果表明:喙尾琵甲幼虫在诱导和非诱导条件下均可分离到具有抑菌活性的抗菌肽,菌液诱导可增强抗菌肽的活性和抑菌谱.