桔小实蝇抗菌肽Bactrocerin-2的分离纯化与鉴定

摘要

采用阳离子交换层析、RP-FPLc及RP-HPLC分离纯化技术,从细菌诱导的桔小实蝇蛹中分离鉴定出桔小实蝇抗菌肽Bactrocerin-1的同系物Bactrocerin-2.结果表明:Bactrocerin-2含有20个氨基酸残基,分子量为2311.51 u,序列为VTKTWIKVIRGIGKSKIKWA;并且Bactrocerin-2与Bactrocerin-1的相似性极高,氨基酸同源性达到90％；该肽与鞘翅目Coleoptericin C-末端的20个氨基酸也具有较高的相似性.氨基酸组成分析结果表明,该肽是一种疏水、带正电荷的抗菌肽.该研究将有助于对昆虫天然免疫反应的认知,并为设计有效的抗菌分子奠定基础.%Bacttocerin -2 (20 -residues )was purified from the immunized pupae of oriental fruit fly Bactrocera dorsalis Hendel by cation-exchange chromatography, RP-FPLC and RP-HPLC. It was an isoform of Bactrocerin-1. Molecular mass of Bactrocerin -2 was determined as 2 311.51 u by MALDI -TOF -MS. Complete amino acid sequences was VTKTWIKVIRGIGKSKIKWA. It showed very high similarity to C -terminal sequences of Coleoptericin. The composition of amino acid residues revealed that Bactrocerin-2 was a hydrophobic, positively charged peptide.