Abstract 2375 An alteration in inter-subunit communication within F420H2:NADP+ oxidoreductase: From negative to no cooperativity

F420H2:NADP+ oxidoreductase (Fno) catalyzes the reversible reduction of NADP+ to NADPH by using the reduced F420 cofactor as a hydride donor. Both NADPH and the F420 cofactor are essential in various metabolic processes in methanogenic and sulfate-reducing archaea. Previous steady-state kinetic studies of wild-type Fno revealed a downward and concave curvature Lineweaver-Burk plot, indicating negative cooperativity. Furthermore, pre-steady-state kinetic analyses revealed biphasic kinetics, with an initial burst phase followed by a slow phase.