Cytotoxicity of L-Methioninase Purified from Clinical Isolates of Pseudomonas Species in Cancer Cell Lines

Abstract

Background: L-methioninase is an enzyme that was found in Pseudomonas spp. It changes L-methionine into α-ketobutyrate, ammonia, and methanethiol. It has been thoroughly investigated for possible antibacterial and anticancer activities. Objective: The goal is to find out how well L-methioninase kills colon CaCo-2 and liver HepG2 cancer cells. Methods: The enzyme was taken from 33 different types of Pseudomonas, and their ability to make L-methioninase was tested on M9 media that had been changed. An MTT assay was used to evaluate the cytotoxic activity of HepG2 and CaCo2 cell lines. Results: Only 15 isolates were able to make L-methioninase. The best isolate had a specific activity of 1.4 μg/U protein. The enzyme's cytotoxicity showed that it stopped the growth of the HepG-2 cell line with an IC50 of 67.44 μg/ml, compared to an IC50 of 140.0 μg/ml for the crude enzyme, and it stopped the growth of the CaCo-2 cell line with an IC50 of 20.57 μg/ml, compared to 154.3 μg/ml for the crude enzyme. Conclusions: Isolation of L-methioninase from microbial sources can be an efficient source to produce this cytotoxic agent.