眼斑芫菁丝氨酸蛋白酶基因的全长cDNA克隆及序列分析

Full-length cDNA Cloning and Sequence Analysis of Serine Protease from Mylabris cichorii

丝氨酸蛋白酶是眼斑芫菁消化系统内重要的消化酶,为了更好地了解丝氨酸类蛋白酶在芫菁消化系统中的作用,本研究利用5'cDNA末端快速扩增(5'RACE)和3'RACE的方法获得该基因的全长cDNA序列,登录号为KC954650。该基因的开放阅读框长816 bp,编码271个氨基酸,预计分子质量为28.22kDa,pI为5.09,预测分子式为C1255H1975N321O400S8,不稳定系数为23.35,总亲水性系数为0.286,为疏水性稳定蛋白。序列分析表明该基因编码的蛋白含有丝氨酸蛋白酶的保守功能位点,与赤拟谷盗在系统进化关系上最近。本研究首次从眼斑芫菁体内克隆得到丝氨酸蛋白酶基因,为后期研究芫菁体内的消化代谢奠定基础。

The serine protease is a important digestive enzyme in the digestive system of Mylabds Cichorii.In order to better understand the serine protease in the role of digestive system,a full-length cDNA of the seine protease gene from Mylabds cihorii （G eneBank accession no.KC954650） was obtained by 5＇rapid amplification cDNA ends （5＇RACE） and 3 ＇RACE.This gene with an open reading frame of 816bp encodes a deduced protein of 271 amino acids residues,with a predicted molecular mass of 28.22kDa and isoeletric point （pI） of 5.09.Its predicted molecular formula is C1255 H1975 N321 O400S8.Bioinformatical analysis showed that its instability index is 23.35 and the GRAVY 0.286,suggesting that it is a stable hydrophobic protein.Sequence analysis showed that the deduced protein has the conserved sites of serine proteases and the closest phylogenetic relationship with Tdbolium castaneum.This study is the first to get the ssrine protease gene from Mylabris Cichorii and provide the basis for further research on digestion metabolism in the blister beetles.