Adenylate cyclase in silkworm. Effects of adenosine 3'-phosphate and 2'-deoxyadenosine 3'-phosphate on the enzyme system in fat body.
Adenosine 3'-phosphate and 2'-deoxyadenosine 3'-phosphate inhibit silkworm fat body adenylate cyclase. The inhibition has a rapid onset, and is dependent on the concentration of Mn2+ or Mg2+. The concentrations of 2'-deoxy-3'-AMP required for 50% inhibition (Ki) are 13 microM with 2 mM Mn2+ and 32 microM with 10 mM Mg2+. These Ki values are 7-30 times lower than that for 2'-deoxyadenosine. Stimulation of adenylate cyclase by NaF renders the activity more sensitive to the nucleotide inhibition, reducing the Ki value to 4 microM in the presence of Mn2+. The inhibitory activity is specific for adenine 3'-nucleotide; Ki for 2'-AMP and 5'-AMP are ten times or more higher than that for 3'-AMP, and the other 3'-nucleotides including 8-bromo-3'-AMP, 3'-IMP and 3'-GMP have little or no inhibitory activity.
D000249:Adenosine Monophosphate / Q000494:pharmacology*; D000067956:Adenylyl Cyclase Inhibitors; D000273:Adipose Tissue / Q000201:enzymology*; D000818:Animals; D012831:Bombyx / Q000201:enzymology*; D000242:Cyclic AMP / Q000494:pharmacology; D005216:Fat Body / Q000201:enzymology*; D007700:Kinetics
D000067956:Adenylyl Cyclase Inhibitors; D000249:Adenosine Monophosphate; D000242:Cyclic AMP