A putative cytotoxic serine protease from Salmonella typhimurium UcB5 recovered from undercooked burger.

ABSTRACT: A putative virulence exoprotease designated as UcB5 was successfully purified from the bacterium Salmonella typhimurium to the electrophoretic homogeneity with 13.2-fold and 17.1% recovery by hydrophobic, ion-exchange, and gel permeation chromatography using Phenyl-Sepharose 6FF, DEAE-Sepharose CL-6B, and Sephadex G-75, respectively. By applying SDS-PAGE, the molecular weight was confirmed at 35 kDa. The optimal temperature, pH, and isoelectric point were 35 °C, 8.0, 5.6 ± 0.2, respectively. UcB5 was found to have a broad substrate specificity against almost all the tested chromogenic substrates with maximal affinity against N-Succ-Ala-Ala-Pro-Phe-pNA achieving K_m of 0.16 mM, K_cat/K_m of 3.01 × 10⁵ S^-1 M^-1, and amidolytic act

SUBMITTER: Kotb E 

PROVIDER: S-EPMC9998444 | biostudies-literature | 2023 Mar

REPOSITORIES: biostudies-literature