虎纹捕鸟蛛毒素-III及其天然突变体的纯化与鉴定(英文)  

Purification and Characterization of a Neurotoxic Peptide Huwentoxin-III and a Natural Inactive Mutant from the Venom of the Spider Selenocosmia huwena Wang (Ornithoctonus huwena Wang)

作　　者：黄仁槐[1] 刘中华[1] 梁宋平[1] 

机构地区：[1]湖南师范大学生命科学学院,长沙410081

出　　处：《生物化学与生物物理学报》2003年第11期976-980,共5页

基　　金：国家自然科学基金资助项目 (No .3 0 170 193 )~~

摘　　要：虎纹捕鸟蛛毒素 III及其天然突变体是从虎纹捕鸟蛛粗毒中分离得到的两个毒素多肽。虎纹捕鸟蛛毒素 III含 33个氨基酸残基 ,其中包含 6个半胱氨酸残基 ;而其天然突变体只比虎纹捕鸟蛛毒素 III少了C端的色氨酸残基。MALDI TOF质谱测得虎纹捕鸟蛛毒素 III及其天然突变体的分子量分别为 385 3.35和 36 6 7.4 0。通过比较其理论分子量和质谱测定的分子量表明两个多肽的 6个半胱氨酸残基分别形成了三对二硫键。虎纹捕鸟蛛毒素 III与从同一种蜘蛛分离得到的凝集素 I具有 70 .5 %的序列相似性。生物学活性实验表明 ,虎纹捕鸟蛛毒素 III具有使美洲蜚蠊可逆的致瘫作用 ,其半有效剂量 (ED50 )为 (1 92 .95±1 2 0 .84 ) μg/g (P =0 .95 ) ,而且能加强由电刺激引起的大鼠输精管收缩 ;而其天然突变体却不具有上述生物学活性 ,表明C端色氨酸残基为虎纹捕鸟蛛毒素 III生物学活性相关残基 ;同时虎纹捕鸟蛛毒素 III及其天然突变体都不具有类似于凝集素 I对红细胞的凝集活性 ,表明虎纹捕鸟蛛毒素 III和凝集素A novel neurotoxic peptide, named huwentoxin III, and a natural mutant have been isolated from the venom of the spider Selenocosmia huwena Wang (Ornithoctonus huwena Wang). The average molecular weights of the two peptides were determined as 3853.35 and 3667.40 by mass spectrometry, respectively. Huwentoxin III has 33 amino acid residues containing 6 cysteine residues. Its natural mutant is only truncated a tryptophan residue from C terminals of huwentoxin III. The sequences of the two peptides show 70.5% sequence similarity with that of lectin like peptide SHL I previously isolated from the venom of the same spider, while they cannot agglutinate human erythrocytes. Huwentoxin III can reversibly paralyze cockroaches for several hours with an ED 50 of (192.95±120.84) μg/g (P=0.95) (x±s) and can enhance the muscular contractions elicited by stimulating the nerve of the isolated rat vas deferens, however, the mutant of huwentoxin III has no such effect, which suggests that Trp 33 was an important residue related to the biological function of huwentoxin III.

关 键 词：虎纹捕鸟蛛毒素-Ⅲ 天然突变体 纯化 鉴定 蜘蛛毒素 神经毒素多肽 虎纹捕鸟蛛 

分 类 号：Q516[生物学—生物化学]