L-methionine gamma-lyase (Trichomonas vaginalis) (TvMGL)

L-methionine gamma-lyase (TvMGL) is a pyridoxal-5'-phosphate (PLP)-dependent enzyme that is essential for the metabolism of the anaerobic protozoan parasite Trichomonas vaginalis. It catalyzes the alpha,gamma-elimination and alpha,beta-elimination of sulfur-containing amino acids, such as L-methionine and L-homocysteine, to produce methanethiol, alpha-ketobutyrate, and ammonia [1, 6]. Because humans and other mammals lack a homologous enzyme for methionine degradation, TvMGL is considered a high-value selective therapeutic target for treating trichomoniasis, the most common non-viral sexually transmitted infection [2, 4]. Drugs like trifluoromethionine act as suicide substrates or pro-drugs; they are converted by TvMGL into toxic intermediates (e.g., trifluoromethanethiol) that specifically disrupt parasite viability while sparing host cells [2, 8]. The target is of particular interest in the development of alternative therapies to overcome increasing resistance to standard nitroimidazole treatments [3, 11].

Other names

MethioninaseL-methionine gamma-demethiolaseMethionine lyaseGamma-cystathionaseMGL

Conversion of methionine analogs into toxic volatile thiols and alpha-keto acids through alpha,gamma-elimination reactions (pro-drug activation/suicide substrate inhibition).