柞蚕抗菌肽的分离纯化及杀菌效应

Isolation and Purification of Antibacterial Peptide from Chinese Oak Silkworm, Antheraea pernyi and Its Bactericidal Effects

大肠杆菌 (E .coliK12 D3 1)诱导的柞蚕 (Antheraeapernyi)蛹血淋巴 ,经加热处理后 ,进行CM -Sepharose阳离子交换层析 ,FPLCPepRPC反相柱及HPLCHi-PoreC18反相柱层析 ,纯化得到一类抗菌肽 .SDS -聚丙烯酰胺凝胶电泳鉴定其相对分子质量约为 2 4 0 0 ,氨基酸组成分析表明其富含赖氨酸、丙氨酸和甘氨酸 ,摩尔分数分别为 18 6 %、15 5 %和 13 6 % ,不含甲硫氨酸、半胱氨酸、酪氨酸和组氨酸 .

Injection of live nonpathogenic bacteria, Esherichia coli K 12 D 31 into pupae of the Chinese oak silkworm, Antheraea pernyi, induced antibacterial peptides in the hemolymph. The major antibacterial peptide was purified with CM-Sepharose cation-exchange chromatography, reverse phase chromatography on FPLC system and C 18 column reverse phase chromatography on HPLC system. The purified peptide had a molecular mass of about 2 400 as determined by SDS-PAGE and its amino acid composition was shown to be rich in lysine , alanine and glycine, while lacking in methionine , cysteine , tyrosine and histidine. The molar content of lysine, alanine and glycine was 18 6%,15 5%,13 6% respectively. Inhibitory spectrum showed that it was potent against several Gram-negative and Gram-positive bacteria.