九香虫防卫素基因CcDef1的克隆及特征分析

Cloning and Characterization of a Defensin Gene CcDef1 from Coridius Chinensis

九香虫 Coridius chinensis是一种重要的资源昆虫,防卫素是抗菌肽家族中一个重要的成员。本文从九香虫中克隆了一种防卫素基因 CcDef1 ,其cDNA的长度为395 bp,包含一个300 bp的开放阅读框,编码99个氨基酸。CcDef1的前体由信号肽、前体肽和成熟肽组成,成熟CcDef1形成包含1个α-螺旋、2个β-折叠片和3个二硫键的三维结构。CcDef1蛋白的相对分子量为4589.37Da,总净电荷量为+1,理论等电点为7.84。同源性和聚类分析显示,CcDef1与红尾碧蝽 Palomena prasina 防卫素的亲缘关系最近。该研究为进一步明确 CcDef1 基因的功能及开发新型抗菌药物奠定基础。

Coridius chinensis is an important resource insect and defensin is an important member of the antimicrobial peptides family. In this study,a defensin gene,designated as CcDef 1 ,was cloned from C. chinensis . The CcDef 1 cDNA is 395 bp in length,containing a 300 bp open reading frame (ORF) that encodes 99 amino acids. The precursor of CcDef 1 is composed of a signal peptide,a propeptide and a mature peptide. The mature CcDef 1 forms a three-demensional structure consisted of 1 α-helix,2 β-pleated sheets and 3 disulfide bonds. The molecular weight of CcDef 1 protein is 4589.37 Da,the total net charge is +1,and the theoretical isoelectric point is 7.84. CcDef 1 protein is involved in the immune protection process of organisms. Homology and cluster analyses showed that CcDef 1 possesses the closest relationship with that of Palomena prasina and Halyomorpha halys . The study laid the foundation for futher clarifying the function of CcDef 1 gene and developing new antibacterial drugs.