九香虫溶菌酶CcLys2的基因克隆与生物信息学分析

Gene Cloning and Bioinformatics Analysis of Lysozyme CcLys2 from Coridius chinensis

九香虫Coridius chinensis是一种药食两用的资源昆虫,溶菌酶是一种能水解细菌中黏多糖的胞壁质酶。本研究克隆了一种九香虫溶菌酶基因CcLys2,其cDNA长1096 bp,包含一个长672 bp的开放阅读框,编码223个氨基酸(aa)。九香虫溶菌酶蛋白CcLys2的N端包含一段由13 aa组成的信号肽,成熟CcLys2是一种分子量为23.34 kDa的分泌型亲水蛋白。成熟CcLys2形成7个α-螺旋和2个β-折叠片的三维分子结构,并由4个二硫键稳定其构象。同源性和聚类分析表明,CcLys2与来自斯氏珀蝽Plautia stali的C-型溶菌酶的亲缘关系最近。生物信息学分析结显示,CcLys2很可能属于具有消化作用的C-型溶菌酶。本研究为今后进一步阐明CcLys2基因的功能及开发新型抗菌药物奠定基础。

Coridius chinensi is an important resource insect as medicine and food. Lysozyme, also known as muramidase or N-acetylmuramide glycanhydrolase, can hydrolyze mucopolysaccharide in bacteria. In this study, a lysozyme gene, named CcLys2,was cloned from C. chinensis. The cDNA of CcLys2 is 1,096 bp in length and contains an open reading frame(ORF) of 672 bp that encodes 223 amino acids(aa). The CcLys2 zymoprotein contains a signal peptide composed of 13 aa at N-terminus. The mature CcLys2 is a secretory hydrophilic protein with a molecular weight of 23.34 kDa, and forms a three-dimensional molecular structure of 7 α-helixes and 2 β-pleated sheets with 4 disulfide bonds to stabilize the conformation. Homology and cluster analyses show CcLys2 possesss the closest relationship with C-type lysozyme from Plautia stali. Bioinformatics analysis show that CcLys2 probably belongs to digestive C-type lysozyme. This study lays a foundation for further elucidating the function of the CcLys2 gene and developing new antimicrobials in the future.