摘要
目的:预测海洋菌Rheinheimera sp.QH分泌的角蛋白酶KerQH2的结构特征及与底物的互作位点,为深入研究KerQH2对角蛋白底物的降解机理提供理论依据。方法:应用生物信息学技术对KerQH2的结构特征、作用于角蛋白底物的可能位点及关键氨基酸等进行分析。结果:KerQH2为S8家族丝氨酸蛋白酶,其分子表面无规则卷曲占比较高,α-螺旋与β-折叠占比较低且多位于酶分子内部。KerQH2具有保守的催化三联体(Asp8、His41和Ser197),催化三联体区域表面静电势为中性。KerQH2催化结构域中含有大量保守的极性氨基酸及芳香族氨基酸,与底物结合有关的序列富含Gly和Ala。KerQH2主要切割疏水性氨基酸Val(V)/ILe(I)和极性氨基酸Cys(C)/Gln(Q)之间形成的肽键。结论:角蛋白酶KerQH2的特殊结构有助于其降解结构复杂角蛋白分子,这可能是海洋菌对海洋寡营养环境的一种适应性。
Objective:To analyze and predict the structural characteristics and the site of interaction with the substrate of keratinase KerQH2 from marine bacteria Rheinheimera sp.QH,and to provide theoretical basis for further study on the degradation mechanism of keratin substrate by KerQH2.Methods:The bioinformatics technology was used to analyze the structural characteristics of keratinase KerQH2 and its possible sites and key amino acids on the keratin substrate.Results:KerQH2 was an S8 family serine protease,and the proportion of random coil on the molecular surface of KerQH2 was high;The proportion of α-helix and β-sheet was low,which were mainly located inside the enzyme molecule.KerQH2contained a conserved catalytic triad in the order of Asp8,His41,Ser197.The surface electrostatic potential in the catalytic triad area was neutral.The KerQH2 catalytic domain contained a large number of conserved polar amino acids and aromatic amino acids,in addition to the sequences related to substrate binding were rich in Gly and Ala.KerQH2 mainly cut the peptide bond formed between hydrophobic amino acid Val(V)/ILe(I) and polar amino acid Cys(C)/Gln(Q).Conclusion:The special structure of KerQH2 helps to degrade complex keratins,which may be an adaptation of marine bacteria to marine oligotrophic environment.
作者
栗学清
庞鑫
高慧芳
张廉芸
宋英达
武翠玲
LI Xueqing;PANG Xin;GAO Huifang;ZHANG Lianyun;SONG Yingda;WU Cuiling(Department of Biochemistry and Molecular Biology,Changzhi Medical College,Changzhi 046000,China;Department of Mental Health,Changzhi Medical College,Changzhi 046000,China;Department of Clinical Medicine,Changzhi Medical College,Changzhi 046000,China)
出处
《食品工业科技》
CAS
北大核心
2022年第9期125-130,共6页
Science and Technology of Food Industry
基金
山西省自然科学基金项目(201801D221284)
长治医学院科学技术带头人(XS202002)。
