虎纹捕鸟蛛毒素XI (HWTX-XI) 突变体的真核表达及活性鉴定

Expression and characterization of Huwentoxin-XI (HWTX-XI) and its mutants

摘要:

虎纹捕鸟蛛毒素-XI (HWTX-XI) 是从虎纹捕鸟蛛粗毒中分离的含55 个氨基酸残基的蛋白质，兼有胰蛋白酶抑制活性和电压门控钾离子通道抑制活性。通过突变HWTX-XI 上的钾离子通道抑制活性关键氨基酸残基设计了2 个突变体 (分别突变以下氨基酸残基：R₅I,R₁₀T,R₂₅A 和R₅I,R₂₅A)，利用pVT102U/α 表达载体在酿酒酵母S78 中成功表达并获得了高纯度的重组蛋白质；通过分光

关键词:虎纹捕鸟蛛毒素XI; 真核表达; 突变体; 胰蛋白酶抑制活性; 钾离子通道抑制活性

Abstract:

Huwentoxin-XI (HWTX-XI) is a protein isolated from the crude venom of spider Ornithoctonus huwena. It has 55 amino acid residues containing 6 cysteine residues forming 3 disulfide bonds. It shows potent inhibitory effect on trypsin and voltage-gated potassium channels in rat dorsal root ganglion cells. According to the structure-function relationship of HWTX-XI, we designed two mutants through mutation of potassium channel inhibition related amino acid residues (R5I,R10T,R25A and R5I,R25A) and then expressed them with high purity by using the vector pVT102U on Saccharamyces cerevisiae strain S78; The two mutants had the same trypsin inhibition activity as HWTX-XI, whereas their potassium channel inhibition activity and animal toxicity were much lower than those of HWTX-XI. This study is helpful for designing drugs of trypsin related diseases based on HWTX-XI.

Key words:HWTX-XI; mutant; eukaryotic expression; trypsin inhibition activity; potassium channel inhibition activity