羊源肺炎克雷伯菌IutA蛋白的生物信息学分析及原核表达OA

[Objective]To analyze the bioinformatics characteristics of the IutA protein from Klebsiella pneumoniae of ovine origin,providing a theoretical basis for its research as a candidate subunit vaccine protein.[Methods]Bioinformatics software was utilized to predict the physicochemical properties and structural characteristics of the IutA protein.Using the genomic DNA of K.pneumoniae as a template,the IutA gene was amplified via PCR.The recombinant expression plasmid pET-32a-IutA was constructed.Positive recombinant vectors were identified by double-enzyme digestion electrophoresis and gene sequencing.The verified plasmid was transformed into Escherichia coli BL21(DE3)to induce recombinant protein expression.SDS-PAGE and Western blot were employed to detect protein expression.[Results]Bioinformatics prediction results indicated that the IutA protein consists of 731 amino acids,with a relative molecular mass of approximately 80.72 kDa and a theoretical isoelectric point of 4.80,classifying it as a stable hydrophilic protein.The protein contains one signal peptide and 22 transmembrane β-barrel domain.The amino acids at positions 44-731 belong to the conserved domain of the TONB-dependent siderophore receptor.The protein possesses 28 B-cell epitopes.Enzymatic digestion and sequencing confirmed the correct construction of the recombinant plasmid.SDS-PAGE and Western blot analyses revealed a specific target protein band of approximately 91 kDa,with the expression products predominantly present in inclusion bodies.[Conclusion]The physicochemical properties and structural characteristics of the IutA protein were obtained through bioinformatics prediction.The recombinant plasmid pET-32a-IutA was successfully constructed,and IutA protein expression was achieved in E.coli BL21(DE3),with the expression products existing mainly in the form of inclusion bodies.This study provides a foundation for subsequent evaluation of the immunogenicity of the IutA protein and the development of its subunit vaccine.