1.2.1.92 3,6-anhydro-alpha-L-galactopyranose + NAD(P)+ + H2O = 3,6-anhydro-L-galactonate + NAD(P)H + H+ - - 1.2.1.92 3,6-anhydro-alpha-L-galactopyranose + NAD(P)+ + H2O = 3,6-anhydro-L-galactonate + NAD(P)H + H+ catalytic mechanism, detailed overview. The catalytic process of VvAHGD involves both the two catalytic residues, Cys282 and Glu248, which not only undergo conformational changes but also function as gatekeepers between the cofactor channel and the substrate channel. The conformational changes of Cys282 and Glu248 lead to the connection and interruption of the cofactor channel and the substrate channel, which promotes the productive binding of NADPþ/L-AHG and the efficient release of NADPH and L-AHGA during the catalysis and therefore leads to the high catalytic activity of VvAHGD -, 763364