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

• DOI: 10.1007/s11274-020-02943-x
• Publication Date: 2020-10-08T03:33:24Z
• Authors: Manoj Kumawat; Ranu Singh; Irungbam Karuna; Neeraj Ahlawat; Sushma Ahlawat
• Keywords: Salmonella typhimurium; Protein Folding; 0303 health sciences; Peptidylprolyl Isomerase; Gene Expression Regulation, Enzymologic; Recombinant Proteins; Substrate Specificity; 03 medical and health sciences; Bacterial Proteins; Escherichia coli; Electrophoresis, Polyacrylamide Gel; Amino Acid Sequence; Cloning, Molecular

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.