电泳制备家蝇幼虫抗菌肽及其性质

通过体壁损伤法诱导家蝇幼虫产生免疫血淋巴,经沸水浴热变性,透析浓缩处理,后经Tricine SDS PAGE得到诱导前后家蝇幼虫血淋巴中蛋白差异表达带,将该条带电泳回收,复性,抗菌活性检测等步骤,分离纯化得到3种抗菌肽:MDL 1、MDL 2、MDL 3.研究结果表明:MDL 1分子中富含Gly,相对分子质量为6200,对革兰氏阴性菌E.coli有较强抗性;MDL 2分子中富含Pro,相对分子质量为11000,对革兰氏阴性菌E.coli和革兰氏阳性菌S.aureus均有抗性;MDL 3分子中富含Gly,相对分子质量为14000,对革兰氏阳性菌S.aureus有较强抗性;3种抗菌肽具有很强的温度耐受性,均没有凝血活性和溶血活性.同时电泳制备抗菌肽的实验方法为此类微量生物活性物质的分离纯化提供了有效的途径.

Electrophoretic Preparation and Biologic Characterization of Antibacterial Peptides from Musca Domestica Larvae

The immunized hemolymph was produced from Musca domestica Larvae by inducing injury. Three antibacterial peptides were purified by means of boiling water bath, dialysis and concentration, Tricine-SDS-PAGE preparation, and retrieval and renatural of peptides. The result of amino acids analysis showed that there were abundant alkaline amino acid in these antibacterial peptides. The molecule weight of antibacterial peptide 1 ( MDL-1) was 6200. It contained abundant Gly, which had potential activity against Gram-negative bacteria, E.coil. MDL-2 ,molecule weight was 11000,contained plentiful Pro, potently acted on Gram-positive and Gram-negative bacteria, E. coil and S. aureus. MDL-3, with molecule weight of 14 000 and abundant Gly, showed antibacterial activity against Gram-positive,S.aureus. The antibacterial peptides do not have the activity of coagulating red cells, and that suggested that they were not lectin. The electrophrosis is an effective way to prepae the antibacterial peptides. However, the mechanism and the structure of peptides were remained to be clarified.