Soluble guanylyl cyclase heme group (sGC heme group)

The soluble guanylyl cyclase heme group is the key prosthetic unit within the beta subunit of soluble guanylyl cyclase (sGC), the primary intracellular receptor for nitric oxide (NO)[1][2][4][7]. Upon NO binding, the ferrous (Fe(II)) heme undergoes a conformational change that triggers activation of sGC's catalytic domain, resulting in rapid cyclic GMP (cGMP) generation from GTP. This cGMP then drives signaling cascades critical for vasodilation, platelet inhibition, smooth muscle relaxation, and many other physiological effects. The heme group resides specifically in the H-NOX domain of the sGC beta subunit, acting as a highly selective sensor for NO over other gases[1][5][6]. Because of its central role in cardiovascular and neurological signaling, and its responsiveness to both endogenous NO and therapeutic nitrovasodilators, the sGC heme group is a major drug target for controlling blood pressure, heart failure, pulmonary hypertension, and related conditions[2][4][7][8]. Recent therapeutic innovations have led to development of both heme-dependent stimulators and heme-independent activators, expanding options for patients in whom NO signaling or heme function is impaired.

Other names

sGC hemeHeme moiety of soluble guanylyl cyclaseH-NOX domain heme

Nitric oxide donors: donate NO, which binds sGC heme, activating the enzyme via Fe-NO complex formation and increasing cGMP synthesis\nsGC stimulators: bind to or near the heme group, stabilizing the active conformation of sGC independent of NO availability\nsGC activators: bind the oxidized/heme-free configuration of sGC, allowing activity even if the endogenous heme-Fe(II) is lost or oxidized