Goffenberg S I, Zhuravlev I V
Biokhimiia. 1988 Jul;53(7):1214-9.
The effects of magnesium and sodium ions on adenylate cyclase activity in plasma membranes from chicken heart and eggshell gland mucosa were studied. It was found that the increase in magnesium chloride concentration from 5 to 40 mM results in the stimulation (4.1-fold) of the adenylate cyclase activity. The increase in sodium chloride concentration up to 150 mM stimulated the enzyme activity 2-fold. The stimulation of adenylate cyclase by magnesium and sodium ions was less pronounced in the eggshell gland. GTP did not activate adenylate cyclase. The activating effect of magnesium and sodium ions was accompanied by the attenuation of the enzyme sensitivity to NaF, guanylyl imidodiphosphate and isoproterenol. Activation by guanylyl imidodiphosphate was completely abolished in the presence of 40 mM magnesium chloride. It is assumed that high concentrations of the salt promote subunit dissociation of the adenylate cyclase regulatory protein and its interaction with the catalytic subunit in the presence of endogenous nucleotides. The differences in the adenylate cyclase sensitivity to cations in chicken heart and eggshell gland mucosa correlate with the amount of pertussis toxin substrate.
研究了镁离子和钠离子对鸡心脏及蛋壳腺黏膜质膜中腺苷酸环化酶活性的影响。发现氯化镁浓度从5 mM增加到40 mM会导致腺苷酸环化酶活性受到刺激（4.1倍）。氯化钠浓度增加至150 mM会使该酶活性受到2倍的刺激。在蛋壳腺中，镁离子和钠离子对腺苷酸环化酶的刺激作用不太明显。GTP不能激活腺苷酸环化酶。镁离子和钠离子的激活作用伴随着该酶对氟化钠、鸟苷酰亚胺二磷酸和异丙肾上腺素敏感性的减弱。在存在40 mM氯化镁的情况下，鸟苷酰亚胺二磷酸的激活作用完全被消除。据推测，高浓度的盐会促进腺苷酸环化酶调节蛋白的亚基解离，并使其在存在内源性核苷酸的情况下与催化亚基相互作用。鸡心脏和蛋壳腺黏膜中腺苷酸环化酶对阳离子敏感性的差异与百日咳毒素底物的量相关。
