FIGURE 8.

Schematic representation of different states of sGC. Previous biochemical and structural studies with adenylate cyclases and guanylate cyclases have shown that there is a low activity (open) conformation and a high activity (closed) conformation. Basal activity is shown in the open conformation, and the high activity closed conformation is shown the presence of excess NO. The 1-NO form is in an intermediate state. NO is shown bound to the distal site of the heme; however, it probably resides in the proximal site in the active (excess NO) state.