Activation mechanism of human soluble guanylate cyclase by stimulators and activators

Soluble guanylate cyclase (sGC) is a validated drug target for cardiovascular diseases. Here, the authors report structures of human sGC in complex with NO and sGC stimulators or activator, providing insight into the mechanism of sGC activation by pharmacological compounds. Soluble guanylate cyclase (sGC) is the receptor for nitric oxide (NO) in human. It is an important validated drug target for cardiovascular diseases. sGC can be pharmacologically activated by stimulators and activators. However, the detailed structural mechanisms, through which sGC is recognized and positively modulated by these drugs at high spacial resolution, are poorly understood. Here, we present cryo-electron microscopy structures of human sGC in complex with NO and sGC stimulators, YC-1 and riociguat, and also in complex with the activator cinaciguat. These structures uncover the molecular details of how stimulators interact with residues from both beta H-NOX and CC domains, to stabilize sGC in the extended active conformation. In contrast, cinaciguat occupies the haem pocket in the beta H-NOX domain and sGC shows both inactive and active conformations. These structures suggest a converged mechanism of sGC activation by pharmacological compounds.

Automated summary

The authors present structures of human sGC in complex with NO and sGC stimulators or activator, shedding light on the mechanism of sGC activation by pharmacological compounds.