Salmonella Typhimurium (ST) is a Gram-negative zoonotic pathogenic bacterium that causes infectious disease in humans as well as in animals. It causes foodborne diarrheal or gastrointestinal illness and fever called salmonellosis, which is a leading cause of millions of deaths worldwide. Salmonellaenterica serovar Typhimurium (S. Typhimurium) during its pathogenesis take away the actin cytoskeleton of their host cells and this is the crucial step of its infection cycle. Cyclophilin A, a type of peptidyl-prolyl isomerase that’s encoded by the ppiA gene in ST, plays pleiotropic roles in maintaining bacterial physiology. In this investigation, the proteomic characterization of the peptidyl-prolyl cis–trans isomerase- A (Cyclophilin A) from Salmonella Typhimurium is reported. Cyclophilin A (CypA) protein from Salmonella Typhimurium proved to be highly conserved and homologous protein sequence compared to other organisms. This protein was expressed in Escherichia coli followed by its purification in a recombinant form protein exhibited a characteristic PPIases activity (V_max = 0.8752 ± 0.13892 µmoles/min, K_m = 0.9315 ± 0.5670 µM) in comparison to control. The mass spectrometry analysis of Cyp A protein-peptide showed a highest sequence similarity with the cyclophilin protein of Salmonella. PPIases proteins (enzyme) data suggest that Ppi-A has roles in the protein folding that may be contributing to the virulence of Salmonella by isomerization of protein outline. These results suggest an active and vital role of this protein in protein folding along with regulation in Salmonella Typhimurium.

鼠伤寒沙门氏菌 (ST) 是一种革兰氏阴性人畜共患病原菌，可引起人类和动物的传染病。它会导致食源性腹泻或胃肠道疾病以及称为沙门氏菌病的发烧，这是全球数百万人死亡的主要原因。沙门氏菌血清型鼠伤寒沙门氏菌（S. Typhimurium）在其发病过程中会带走宿主细胞的肌动蛋白细胞骨架，这是其感染周期的关键步骤。亲环蛋白 A 是一种由ST 中ppiA基因编码的肽基-脯氨酰异构酶，在维持细菌生理方面发挥着多效作用。在这项研究中，来自沙门氏菌的肽基-脯氨酰顺反异构酶-A（亲环蛋白A）的蛋白质组学表征鼠伤寒已有报道。与其他生物体相比，来自鼠伤寒沙门氏菌的亲环蛋白 A (CypA) 蛋白被证明是高度保守的同源蛋白序列。该蛋白质在大肠杆菌中表达，然后以重组形式纯化， 与对照相比，蛋白质表现出特征性 PPIases 活性（V _max  = 0.8752 ± 0.13892 µmoles/min，K _m = 0.9315 ± 0.5670 µM）。Cyp A 蛋白-肽的质谱分析显示与沙门氏菌的亲环蛋白具有最高的序列相似性。PPIases 蛋白质（酶）数据表明 Ppi-A 在蛋白质折叠中起作用，这可能有助于沙门氏菌通过蛋白质轮廓的异构化。这些结果表明该蛋白质在蛋白质折叠以及鼠伤寒沙门氏菌的调节中发挥着积极和重要的作用。