Regulatory role of Glu546 in flavin mononucleotide-heme electron transfer in human inducible nitric oxide synthase.

ABSTRACT: Nitric oxide (NO) production by mammalian NO synthase (NOS) is believed to be regulated by the docking of the flavin mononucleotide (FMN) domain in one subunit of the dimer onto the heme domain of the adjacent subunit. Glu546, a conserved charged surface residue of the FMN domain in human inducible NOS (iNOS), is proposed to participate in the interdomain FMN/heme interactions [Sempombe et al. Inorg. Chem.2011, 50, 6869-6861]. In the present work, we further investigated the role of the E546 residue in the FMN-heme interdomain electron transfer (IET), a catalytically essential step in the NOS enzymes. Laser flash photolysis was employed to directly measure the FMN-heme IET kinetics for the E546N mutant of human iNOS oxygenase/FMN (oxyFMN) construct. The temperature dependence of the IET ki

SUBMITTER: Li W 

PROVIDER: S-EPMC3677850 | biostudies-literature | 2013 May

REPOSITORIES: biostudies-literature