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

摘要: 大肠杆菌（E.coli K12D31)诱导的柞蚕（Antheraea pernyi)蛹血淋巴，经加热处理后，进行CM－Sepharose阳离子交换层析，FPLC Pep RPC反相柱及HPLC Hi-Pore C18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2400，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。抗菌谱表明该肽对多种革兰氏阴性和阳性细菌均有抑制作用。

Abstract: 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.