摘要
从菜花烙铁头蛇的毒腺中 ,利用RT PCR进行体外扩增 ,克隆到 2个金属蛋白酶 去整合素基因 ,命名为TJM 1、TJM 2 .TJM 1cDNA全长为 15 2 8bp ,编码 4 81个氨基酸 ;TJM 2cDNA全长为 15 78bp ,编码 4 84个氨基酸 .TJM 1和TJM 2都属于Ⅱ型蛇毒金属蛋白酶 ,由信号肽、前肽、金属蛋白酶、间隔肽和去整合素 5部分组成 .Ⅱ型蛇毒金属蛋白酶氨基酸序列的比较及进化分析显示 ,它可进一步分为两类 ,一类包括大多数Ⅱ型蛇毒金属蛋白酶 (其中含有TJM 1) ,而TJM 2和agkistin则组成了另一类 .并且TJM 2和agkistin的第 4 0 7位和第 4 2 6位残基都是半胱氨酸 ,而在其它Ⅱ型金属蛋白酶的相应位置 ,4 0 7位是丝氨酸 ,4 2 6位则缺失 .TJM 2和agkistin均有可与整合素α2 Ⅰ区域特异性结合的片段Q NRKRHDNAQ(残基 2 76～ 2 84 ) ,这个片段在其它Ⅱ型金属蛋白酶中并没有发现 .因此推断 ,TJM 2和agkistin可能属于一类新型的Ⅱ型蛇毒金属蛋白酶 .
Two cDNAs encoding metalloproteinase-disintegrin, named TJM-1 and TJM-2, were cloned from venom gland of Trimeresurus jerdonii by reverse transcription polymerase chain reaction (RT-PCR). The full-length cDNA of TJM-1 was 1 528 bp and encoded an open reading frame (ORF) of 481 amino acids. That of TJM-2 was 1 578 bp and encoded an ORF of 484 amino acids. Both encoding proteins belonged to the class Ⅱ of snake venom metallproteinases (SVMP) (class P-Ⅱ), consisting of signal peptide sequence, zymogen sequence, metalloproteinase, spacer and disintegrin domains. Phylogenetic analysis of class P-Ⅱ SVMPs revealed it could be further classified into two groups. One group contained most class P-Ⅱ SVMPs including TJM-I. TJM-2 and Agkistin formed the other group. Moreover, the 407 th and 426 th residues in TJM-2 and agkistin were Cys, while in other class P-Ⅱ metalloproteinases 407 th residue was Ser and 426 th residue was deleted. The segments of Q/NRKRHDNAQ (residue 280-288) of TJM-2 and agkistin, which were thought to specifically bind to integrin α 2Ⅰ domain, was also not found in class P-Ⅱ SVMPs. It was predicted that TJM-2 and agkistin might belong to a new type of class P-Ⅱ SVMPs.
出处
《中国生物化学与分子生物学报》
CAS
CSCD
北大核心
2004年第1期6-12,共7页
Chinese Journal of Biochemistry and Molecular Biology
基金
云南省自然科学基金 (No .2 0 0 2C0 0 63M)资助~~
关键词
菜花烙铁头蛇
蛇毒金属蛋白酶
克隆
序列分析
Trimeresurus jerdonii,snake venom metalloproteinases, cloning and sequencing
