Salmonella Typhimurium peptidyl-prolyl cis–trans isomerase C (PPIase C) plays a substantial role in protein folding to maintain the protein structure

Salmonella is a well-known food-borne pathogen causing disease in humans and animals worldwide. Peptidyl-prolyl isomerases (PPIases) catalyse the cis–trans isomerisation of prolyl bound, which is a slow and rate-limiting step of protein folding. Here, we present the biochemical and molecular characterisation of a novel multi-domain parvulin-type, PPIases-C from the pathogenic bacteria Salmonella Typhimurium, annotated as rPpiC. The recombinant plasmid PpiC_pET28c was used for protein induction using 1.5 mM concentration of isopropyl-β-D-thiogalactopyranoside at 30 °C. Subsequently, the protein was identified by using the LC–MS technique showing high match score and sequence coverage with available PPIases-C proteins database. Using the succinyl-ala-phe-pro-phe-p nitroanilide as a substrate, Vmax of the enzyme was found to be 0.8187 ± 0.1352 µmoles/min and Km = 1.6014 ± 0.8449 µM, respectively. With this, we conclude that rPpiC protein is an active form of protein from Salmonella Typhimurium and plays an important role in protein folding.