Effects of isoleucine 135 side chain length on the cofactor donor-acceptor distance within F₄₂₀H₂:NADP⁺ oxidoreductase: A kinetic analysis.

ABSTRACT: F₄₂₀H₂:NADP⁺ Oxidoreductase (Fno) catalyzes the reversible reduction of NADP⁺ to NADPH by transferring a hydride from the reduced F₄₂₀ cofactor. Here, we have employed binding studies, steady-state and pre steady-state kinetic methods upon wtFno and isoleucine 135 (I135) Fno variants in order to study the effects of side chain length on the donor-acceptor distance between NADP⁺ and the F₄₂₀ precursor, FO. The conserved I135 residue of Fno was converted to a valine, alanine and glycine, thereby shortening the side chain length. The steady-state kinetic analysis of wtFno and the variants showed classic Michaelis-Menten kinetics with varying FO concentrations. The data revealed a decreased k

SUBMITTER: Le CQ 

PROVIDER: S-EPMC5614548 | biostudies-literature | 2017 Mar

REPOSITORIES: biostudies-literature