人类一条新的类蛋白质二硫键异构酶cDNA的克隆和表达

利用SMART技术构建了人胎脑cDNA文库，通过大规模测序筛选出一条1645bp的人类cDNA。此cDNA含有一个888bp的开放阅读框（ORF），编码一个296个氨基酸的蛋白质，预测分子量34．0KD。与目前数据库中序列比较，该cDNA编码的蛋白质与蛋白质二硫键异构酶的同源性达36％，命名为类蛋白质二硫键异构酶（PDI－L）基因，多组织Northern blot分析显示PDI－L cDNA在心、脑、肝肾等组织中均有表达，该cDNA的读框片段正确插入到改造后的pBV220表达载体中，获得了预期的表达蛋白。

Cloning Expression of a Novel Human Protein-Disulfide Isomerase Like cDNA

Using the large scale sequencing, a novel human cDNA of 1 645 bp was screened from the cDNA library of human fetal brain. The cDNA contains an ORF encoding a 296-aa protein with a calculated molecular weight of 34.0 KD. Compared with that of current sequence databases, the putative protein was found to have 36% homology with protein-disulfide isomerase (PDI). So this cDNA was named PDI like (PDI-L) gene. Multiple tissue Northern blot analysis shows that PDI-L cDNA is expressed in heart, brain, liver, kidneys and so on. The ORF fragment of PDI-L cDNA was inserted into reconstructed pBV220 expression vehicle and its predicted expressive protein was obtained.