摘要： 根据GenBank中少孢节丛孢菌丝氨酸蛋白酶 P186 基因序列设计特异性引物，运用RT-PCR扩增获得目的基因片段，构建重组表达质粒pET32a-P186，转化到大肠杆菌BL21（DE3），以IPTG进行了诱导表达。结果表明，P186 基因cDNA全长为1 224 bp，编码407个氨基酸，其中第1～21位为信号肽序列，氨基酸序列的第156～167位、192～202位、343～353位分别是天冬氨酸（Asp₁₆₀）、组氨酸（His₁₉₂）、丝氨酸（Ser₃₄₅）活性位点所在区域，属于Subtilase家族，包括2个潜在的N-联糖基化位点（Asn₂₄₉、Asn₃₄₂）及与底物结合的S1区（SBP）Ser₂₅₁Ile₂₅₂Gly₂₅₃和Ala₂₇₇Ala₂₇₈Gly₂₇₉。SDS-PAGE分析结果显示，表达产物的分子质量约为62 kDa。Western Blot分析结果表明，P186重组蛋白可以与抗蛋白粗提液多克隆抗体发生反应。为了揭示少孢节丛孢菌捕食线虫的分子机制，首次克隆并表达了少孢节丛孢菌丝氨酸蛋白酶 P186 基因，为进一步研究丝氨酸蛋白酶P186的生物学功能奠定了基础。

关键词: 少孢节丛孢菌, 丝氨酸蛋白酶P186, 克隆, 表达

Abstract: A pair of specific primers derived from Arthrobotrys oligospora Serine Protease P186 gene in GenBank was designed and used to amplify P186 gene by RT-PCR from total RNA extracted from Arthrobotrys oligospora.The RT-PCR product was cloned into the expression vector pET32a to generate,recombinant pET32a-P186,and pET32a-P186 plasmid was transformed into E.coli BL21(DE3)and induced by IPTG.Sequence analysis demonstrated that P186 cDNA contained a insert of 1 224 bp encoding 407 amino acids,Among them 1-21 for the signal peptide sequence,amino acid sequence of 156-167,192-202,343-353 were aspartic acid(Asp₁₆₀),histidine(His₁₉₂)and serine(Ser₃₄₅)active site area,respectively,which are belonging to the family of Subtilase.The amino acid also contained two potential N-terminal glycosyauon sites(Asn₂₄₉,Asn₃₄₂) and a substrate binding region of S1(SBP)Ser₂₅₁Ile₂₅₂Gly₂₅₃ and Ala₂₇₇Ala₂₇₈Gly₂₇₉.SDS-PAGE analysis showed that the product had a molecular weight of about 62 kDa.Western Blot analysis indicated that the recombinant protein could specifically react with polyclonal antibody against protein crude extracts.In order to reveal the molecular mechanism of Arthrobotrys oligospora predatory nematodes,In this study,the serine protease P186 gene of Arthrobotrys oligospora was firstly cloned and expressed,which laid a foundation of further study on biological function of P186.

Key words: Arthrobotrys oligospora, Serine protease P186, Cloning, Expression

中图分类号: 

• Q78