Arginine Deiminase Enzyme Evolving as a Potential Antitumor Agent

Some melanomas and hepatocellular carcinomas have been shown to be auxotrophic for arginine. Arginine deiminase (ADI), an arginine degrading enzyme isolated from Mycoplasma, can inhibit the growth of these tumors. It is a catabolizing enzyme which catabolizes arginine to Citrulline. Tumor cells do not express an enzyme called arginosuccinate synthetase (ASS) and hence, these cells become auxotrophic for arginine. It is found that ADI is specific for arginine and did not degrade other amino acid. This review covers various aspects of ADIs like origin, properties and chemical modifications for better antitumor activity. Keywords: Arginine, Arginine deiminase (ADI), Arginosuccinate synthetase (ASS), Arginosuccinate lyase (ASL), Hepatocellular carcinoma, malignant melanoma.