Purification and Characterization of Cyclophilin-a Proteins That Associated With Protein Folding in Salmonella Typhimurium

Abstract Salmonella Typhimurium (ST) is the zoonotic pathogenic Gram-negative bacteria to causes infectious disease in humans as well as in animals. It causes gastrointestinal illness and fever called salmonellosis, which is foodborne diarrheal and leading cause of millions of deaths worldwide. Salmonella enterica serovar Typhimurium (S. Typhimurium) during its pathogenesis takeaway 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 research, 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 a highly conserved protein sequence and highly homologous compared to other organisms. This protein was expressed in Escherichia coli and then purified in a recombinant form protein exhibited a characteristic PPIases activity (Vmax = 0.8752 ± 0.13892 µmoles/ min, Km = 0.9315 ± 0.5670 µM) in comparison to control. Also, in this study the mass spectrometry analysis of Cyp A protein-peptide showed the 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.