穴居狼蛛毒中一个抗菌活性多肽的鉴定和纯化

PURIFICATION AND CHARACTERIZATION OF AN ANTIBACTERIAL PEPTIDE FROM VENOM OF LYCOSA SINGORIENSIS

从我国新疆地区产穴居狼蛛的毒液中分离纯化了一种多肽——狼蛛抗菌肽(Lycosin)。穴居狼蛛的粗毒在酸性聚丙烯酰胺凝胶电泳中可分出11条蛋白带,用0.6％的大肠杆菌琼脂胶覆盖在凝胶上进行鉴定表明,电泳迁移率最快的区带有抗菌活性。经鉴定该多肽分子系由43至45个氨基酸残基组成,N-末端为丙氨酸,分子中的碱性和疏水性氨基酸分别占总氨基酸残基数的1/4和1/3。

An antibacterial peptide -by cosin was purified from the venom of Lycosa singoriensis. The purification scheme was outlined. The lyophilized poison gland was homogenized, extracted and the supernatant was lyophilized again. The solution of lyophilized powder was separated into 11 bands by acidic polyacrylamide gel electrophoresis. The gel was overlaid with viable E. coli to detect antibacterial activity. The fastest migrated band showed the antibacterial activity. The active band was cut down and homogenized, extracted and lyophilized. The antibacterial peptide was further purified on Sephadex G-25 gel filtration and HPLC. The amino acid composition of the purified peptide was determined to contain 43 to 45 amino acid residues. the N-terminal residue was alanine. The basic and hydrophobic ami-no acid residues accounted for close to 1/4 and 1/3 of the total amino acid residues respectively.