Tkachuk V A, Avdonin P V, Panchenko M P
Biokhimiia. 1981 Feb;46(2):333-41.
Guanyl nucleotides enhance the activating effect of chloride ions on adenylate cyclase of rabbit heart sarcolemma. Chloride ions decrease the lag period in the effect of guanyl-5'-ylimidodiphosphate (Gpp(NH)p), the non-hydrolyzed analog of GTP, on adenylate cyclase. Guanyl nucleotides and chloride ions exert a synergistic effect on the enzyme activation. The adenylate cyclase activity in the presence of Gpp(NH)p is increased by other anions as well. The activating effect of chloride ions on the enzyme is enhanced by GTP, as well as by GDP. On the contrast, GDP completely inhibits the enzyme activation by isoproterenol. It was assumed that chloride ions favour the formation of a complex between the adenylate cyclase catalytic subunit and the regulatory protein irrespective of the type of guanyl nucleotide, i.e. GTP, Gpp(NH)p or GDP, present in the nucleotide binding site of the regulatory protein.
鸟苷酸增强氯离子对兔心肌肌膜腺苷酸环化酶的激活作用。氯离子缩短了鸟苷-5'-亚氨二磷酸（Gpp(NH)p，GTP的非水解类似物）对腺苷酸环化酶作用的延迟期。鸟苷酸和氯离子对该酶的激活发挥协同作用。在Gpp(NH)p存在时，其他阴离子也能增加腺苷酸环化酶活性。GTP以及GDP均可增强氯离子对该酶的激活作用。相反，GDP完全抑制异丙肾上腺素对该酶的激活。据推测，无论调节蛋白核苷酸结合位点中存在的鸟苷酸类型是GTP、Gpp(NH)p还是GDP，氯离子都有利于腺苷酸环化酶催化亚基与调节蛋白之间形成复合物。
