Abstract
The kinetic characteristics of substrate utilization by hepatic adenylate cyclase were investigated under a variety of incubation conditions, including variations in pH, [substrate], [Mg2+], and in the absence or presence of glucagon. Activities were compared with ATP and 5' adenylylimidodiphosphate [App(NH)p] as substrates. The K(m) for both substrates was about 50 μM; V(max) given with App(NH)p was about 40% lower than obtained with ATP as substrate.