家蚕中的腺苷酸环化酶。3'-磷酸腺苷和2'-脱氧腺苷3'-磷酸对脂肪体中酶系统的影响。

Adenylate cyclase in silkworm. Effects of adenosine 3'-phosphate and 2'-deoxyadenosine 3'-phosphate on the enzyme system in fat body.

作者信息

Morishima I

出版信息

Biochim Biophys Acta. 1980 Jun 13;613(2):507-13. doi: 10.1016/0005-2744(80)90106-0.

Abstract

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.

摘要

3'-磷酸腺苷和2'-脱氧-3'-磷酸腺苷可抑制家蚕脂肪体腺苷酸环化酶。这种抑制作用起效迅速，且依赖于Mn2+或Mg2+的浓度。50%抑制率（Ki）所需的2'-脱氧-3'-AMP浓度在2 mM Mn2+存在时为13 microM，在10 mM Mg2+存在时为32 microM。这些Ki值比2'-脱氧腺苷的Ki值低7至30倍。NaF对腺苷酸环化酶的刺激使该活性对核苷酸抑制更敏感，在Mn2+存在时将Ki值降低至4 microM。抑制活性对腺嘌呤3'-核苷酸具有特异性；2'-AMP和5'-AMP的Ki值比3'-AMP的Ki值高十倍或更多，其他3'-核苷酸包括8-溴-3'-AMP、3'-IMP和3'-GMP几乎没有抑制活性。