Biochemistry

The aim of the project will be the study of physiological functions of two human enzymes, betaine-homocysteine S-methyltransferases 1 and 2 (BHMT-1 and BHMT-2). These enzymes use different methyldonors for the methylation of homocysteine to methionine. Recombinant forms of both enzymes will be purified and inhibition properties of specific inhibitors determined. The most promising inhibitors will be used for the inhibition of both enzymes in cell cultures of hepatic and renal origin. The effect of inhibition of the enzymes on protein expression in cells will be studied using 2D-electrophoresis. Intracellular concentrations of several key metabolites (Met, Hcy, Cys, adoMet, adoHcy, betaine and choline) will be also determined. This proteomics study should help to better understand the roles of BHMT-1 and BHMT-2 in the mammalian metabolism of homocysteine and methionine.