文蛤过氧化氢酶的生物信息学分析

基于NCBI数据库,对文蛤过氧化氢酶基因(MmeCAT)进行生物信息学分析,旨在为文蛤过氧化氢酶的结构与功能的研究提供理论基础。结果表明,该基因编码511个氨基酸。文蛤过氧化氢酶分子量为58 181.29 Da,分子式为C_(2588)H_(3928)O_(767)N_(730)S_(20),理论等电点为8.05,属亲水蛋白。带负电荷氨基酸残基数(Asp+Glu)为63个,带正电荷氨基酸残基数(Arg+Lys)为65个。假设所有半胱氨酸全部形成胱氨酸,其消光系数为63 175 mol/L,相应的吸光度为1.086;假设所有的半胱氨酸均未形成胱氨酸时,消光系数为62 800 mol/L,相应的吸光度为1.079;其半衰期为30 h,脂肪族氨基酸指数为57.28,不稳定系数为27.77(40),可知文蛤过氧化氢酶为稳定蛋白质。亚细胞定位于过氧化物酶体,存在71个磷酸化位点和51个糖基化位点,无信号肽。二级结构以无规卷曲和α-螺旋为主,在物种进化上具有高度的保守性保守结构域预测表明,该基因编码蛋白可能属于典型单功能过氧化氢酶的第三分支。研究文蛤过氧化氢酶结构,能够为文蛤抗逆性品种选育提供理论基础。

Bioinformatics analysis of catalase in saltwater clam M.meretrix

Based on NCBI database, bioinformatics analysis of catalase genes (MmeCAT) in saltwater clam M.meretrixwas conducted to provide theoretical basis for the research on the structure and function of catalase genes. Results showed that the gene encoded 511 amino acids. Molecular weight of the catalase was 58 181.29 Da, molecular formula was C₂₅₈₈H₃₉₂₈O₇₆₇N₇₃₀S₂₀, and theoretical isoelectric point was 8.05, belonging to hydrophilic protein. Total number of negatively charged residues (Asp + Glu) was 63 and that of positively charged residues (Arg + Lys) was 65. Assuming all pairs of Cys residues formed cystines, the extinction coefficient was 63 175 mol/Land the corresponding absorbance was 1.086. When assuming all Cys residues were reduced, the extinction coefficient was 62 800 mol/L and the corresponding absorbance was 1.079. Its estimated half-life was 30 hours and aliphatic index was 57.28. The instability index was computed to be 27.77, which classified the protein as stable. The subcells were located in the peroxisome, with 71 phosphorylation sites and 51 glycosylation sites but without signal peptides. The secondary structures are random coil and alpha helix, being highly conservative in species evolution. The prediction of the conserved domain indicated that this gene coding protein probably belonged to clade 3 branch of monofunctional catalase. The study on the structure of the MmeCATcan provide theoretical basis for the breeding of stress-resistant varieties of M.meretrix.