人致肺纤维化相关因子的克隆和生物信息学分析

Cloning and Bioinformatics Analysis of Human Lung Fibrosis-inducing Factors

几丁质酶是自然界广泛存在的一类降解几丁质的水解酶类,但是直至近些年才在哺乳动物体内发现存在有几丁质酶样蛋白.早年曾于矽肺大鼠中纯化出矽诱导的支气管肺泡灌洗蛋白iSBLP58,体外具有促进人胚肺成纤维细胞2BS增殖的作用,N端测序显示与哺乳动物几丁质酶蛋白家族成员具有高度同源性.生物信息学分析表明,来源于人的结肠、肾和胃的几个表达序列标签(EST)克隆和大鼠的这一蛋白质序列匹配.随后成功地从人肾RNA样品中克隆到一组cDNA,其序列及相应的氨基酸序列彼此高度相似,并与GenBank中的几个人几丁质酶蛋白高度相似.和人基因组序列比较,揭示这些分子可能来自于同一基因,为可变剪切的产物.

Chitinases are ubiquitous chitin-fragmenting hydrolases, however until a fewyears ago that chitinase like proteins have been found in mammalian. A silica-induced bronchoalveolar lavage protein （iSBLP^58） with fibroblast growth promoting activity in silicotic rat, which had high sequence homology with members of the mammalian chitinase protein family has been previously purified and characterized. Bioinformatics analysis showed that several human EST clones from pooled colon, kidney or stomach matched the rat protein sequence. Thereafter clone from human kidney RNA samples with several pairs of primers was managed and a set of sequences was obtained, whose eDNA and amino acid sequences have high similarity with each other and several human chitinases in GenBank. Comparison with human genome sequence suggests that these molecules may be from variant transcripts of same a Pre-mRNA. Here the characterization of these sequences is reported.