Depletion of L-Methionine in Foods with an Engineered Thermophilic Methionine γ-lyase Efficiently Inhibits Tumor Growth.

Abstract

Dietary restriction of l-methionine, an essential amino acid, exerts potent antitumor effects on l-methionine-dependent cancers. However, dietary restriction of l-methionine has not been practical for human therapy because of the problem with the administration of l-methionine concentration in foods. Here, a thermophilic methionine γ-lyase (MGL), that catalyzes the cleavage of the C-S bond in l-methionine to produce α-ketobutyric acid, methanethiol, and ammonia was engineered from human cystathionine γ-lyase and almost completely depleted l-methionine at 65 °C, a temperature that accelerates the volatilization of methanethiol and its oxidation products. The high efficiency of l-methionine lysis may be attributed to the cooperative fluctuation and moderate the structural rigidity of 4 monomers in the thermophilic MGL, which facilitates l-methionine access to the entrance of the active site. Experimental diets treated with thermophilic MGL markedly inhibited prostate tumor growth in mice, and in parallel, the in vivo concentrations of l-methionine, its transformation product l-cysteine, and the oxidative stress indicator malondialdehyde significantly decreased. These findings provide a technology for the depletion of l-methionine in foods with an engineered thermophilic MGL, which efficiently inhibits tumor growth in mice.

• Authors: Yangming Hu, Yan Liu, Jiulin Zhang, Zhijing Zhou, Jiaxue Wang, Hongyang Chen, Meina Huang, Han Hu, Zongjie Dai, Kaizhi Jia
• Journal: Journal of agricultural and food chemistry (J Agric Food Chem) (Nov 01 2023) ISSN: 1520-5118 [Electronic] United States
• PMID: 37909421 (Publication Type: Journal Article)