Mizanur M Rahaman, Anh T Nguyen, Megan P Miller, Scott A Hahn, Courtney Sparacino-Watkins, Soma Jobbagy, Nolan T Carew, Nadiezhda Cantu-Medellin, Katherine C Wood, Catherine J Baty, Francisco J Schopfer, Eric E Kelley, Mark T Gladwin, Emil Martin, Adam C Straub
RATIONALE: Soluble guanylate cyclase (sGC) heme iron, in its oxidized state (Fe(3+)), is desensitized to NO and limits cGMP production needed for downstream activation of protein kinase G-dependent signaling and blood vessel dilation. OBJECTIVE: Although reactive oxygen species are known to oxidize the sGC heme iron, the basic mechanism(s) governing sGC heme iron recycling to its NO-sensitive, reduced state remain poorly understood. METHODS AND RESULTS: Oxidant challenge studies show that vascular smooth muscle cells have an intrinsic ability to reduce oxidized sGC heme iron and form protein-protein complexes between cytochrome b5 reductase 3, also known as methemoglobin reductase, and oxidized sGC...
July 7, 2017: Circulation Research