Tags: Enzyme.
In enzymology a [methionine synthase] reductase (EC 1.16.1.8) is an enzyme that catalyzes the chemical reaction2 [methionine synthase]-methylcob(I)alamin + 2 S-adenosylhomocysteine + NADP+ 2 [methionine synthase]-cob(II)alamin + NADPH + H+ + 2 S-adenosyl-L-methionineThe 3 products of this enzyme are methionine synthase-methylcob(I)alamin S-adenosylhomocysteine and NADP+ whereas its 4 substrates are methionine synthase-cob(II)alamin NADPH H+ and S-adenosyl-L-methionine.Over time the cob(I)alamin cofactor of methionine synthase becomes oxidized to cob(II)alamin rendering the enzyme inactive.