An isoform-specific pivot modulates the electron transfer between the flavin mononucleotide and heme centers in inducible nitric oxide synthase.

ABSTRACT: Intraprotein interdomain electron transfer (IET) between the flavin mononucleotide (FMN) and heme centers is an obligatory step in nitric oxide synthase (NOS) enzymes. An isoform-specific pivotal region near Leu406 in the heme domain of human inducible NOS (iNOS) was proposed to mediate the FMN-heme domain-domain alignment (J Inorg Biochem 153:186-196, 2015). The FMN-heme IET rate is a measure of the interdomain FMN/heme complex formation. In this work, the FMN-heme IET kinetics in the wild type (wt) human iNOS oxygenase/FMN (oxyFMN) construct were directly measured by laser flash photolysis with added synthetic peptide related to the pivotal region, in comparison with the wt construct alone. The IET rates were decreased by the iNOS HKL peptide in a dose-saturable fashion, and the inhibito

SUBMITTER: Zheng H 

PROVIDER: S-EPMC7669679 | biostudies-literature | 2020 Dec

REPOSITORIES: biostudies-literature