中国人血管抑素基因的克隆及其序列分析

Cloning and sequencing of Chinese human angiostatin

目的 :克隆中国人血管抑素 (angiostatin ,ANG)基因全长并进行序列分析。方法 :应用RT -PCR ,将 5例健康人肝脏组织ANG基因克隆到pSP71载体上 ,用Sanger法进行基因测序分析。结果 :通过RT -PCR获得一个 1 1 4 1bp的扩增产物 ,测序发现与已报道的ANG比较 ,国人ANG上有 3个碱基突变位点 :分别为第 82 5位C→T ;第 92 7位T→G和第 1 0 78位G→A。前两个碱基突变氨基酸未发生变化 ,第 3个碱基突变结果使缬氨酸 (Val342 )改变成为蛋氨酸(Met342 )。结论 :克隆得到中国人ANG基因片段 。

Aim:To clone and sequence the full-length angiostatin from Chinese plasminogen. Methods:Chinese angiostatin gene was cloned on the Xho I and EcoR I sites of pSP71 vector by RT-PCR, and then sequenced by using Sanger method through sp6 and T7 promoter primers. Results:A recombinant plasmid pSP-hANG was constructed. Three mutant sites were detected compared with the reported plasminogen cDNA sequence, which were 825 site (C →T), 927 site(T→G) and 1 078 site(G →A),respectively. No amino acid change occurred in the first two mutant sites, but amino acid Val342 was superseded by Met342 in the third mutant site. Conclusion:The variety of base-pair and amino acid in the Chinese angiostatin might involve in genetic polymorphism.