华支睾吸虫分泌蛋白基因（CsCrSP）的克隆和生物信息学分析

目的 筛选cDNA文库识别华支睾吸虫新基因，克隆并构建重组表达载体。 方法 对华支睾吸虫cDNA文库进行筛选，通过BLASTn程序进行序列比对，识别华支睾吸虫新基因，并应用Motifscan，NCBI Conserved Domain Search等程序对其进行结构域及进化树分析。 结果 筛选出华支睾吸虫未知基因Pcs004f03序列，含689 bp；应用Vecter NTI分析，理论相对分子质量（Mr）为21 000，完整的ORF含561 bp，编码187aa。该基因有潜在的糖激化位点、3个N肉豆蔻酰化位点、3个酪蛋白激酶Ⅱ磷酸化位点、蛋白激酶Ｃ磷酸化位点、cAMP-and cGMP依赖蛋白激酶磷酸化位点。利用软件在线搜索发现在第1～50aa内有一明显的信号肽，初步推断CsCrSP为一种分泌蛋白。结论 CsCrSP基因为华支睾吸虫富含半胱氨酸分泌蛋白基因。

Cloning and Bio-informatics Analysis of the CsCrSP from Clonorchis sinensis

Objective To screen cDNA library from Clonorchis sinensis for gene identification, and to clone and construct library of secreted recombinant proteins. Methods cDNA library from Clonorchis sinensis was screened for identifying new genes by Blastn protocol, the sequence of which was further analyzed by Motifscan and NCBI Conserved Domain Search protocol. Results The secreted proteins (Pcs004f03) were identified, with a 689 bp DNA sequence (187aa), and a theoretical molecular weight of Mr 21 100. It is predicted that the gene CsCrSP contains one N-glycosylation site, three N-myristoylation sites, three casein kinase II phosphorylation sites, one cAMP-and cGMP-dependent protein kinase phosphorylation site and protein kinase C phosphorylation site, a signal peptide at N-terminals and SCP-like extracellular protein domain. Conclusion The CsCrSP gene is a secretory cysteine-rich protein with a SCP-like extracellular protein domain.