Properties of Detergent‐Dispersed Adenylate Cyclase from Cerebral Cortex. Presence of an Inhibitor Protein
Properties of Detergent‐Dispersed Adenylate Cyclase from Cerebral Cortex. Presence of an Inhibitor Protein
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大脑皮层中去污剂分散的腺苷酸环化酶的特性。抑制剂蛋白的存在。
DOI：
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发表时间：
1982
影响因子：
4.7
通讯作者：
G. Drummond
中科院分区：
文献类型：
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作者：
M. Sano;G. Drummond
摘要：用非离子去污剂Lubrol 12A9从洗涤的兔大脑皮层颗粒状部分中溶解腺苷环化酶，再经UltroGel ACA凝胶过滤或DEAE Bio-Gel A层析。两种方法均可将该酶分解成两种组分，一种对鸟氨酰亚胺二磷酸(GPP(NH)p)和NaF不敏感，但受钙和钙调蛋白刺激；另一种对GPP(NH)p和NaF相对不敏感，对钙和钙调素相对不敏感。这些数据支持大脑皮层中存在两种独立形式的腺苷环化酶的可能性，一种是由鸟核苷酸调节蛋白调节的，另一种是由钙-钙调蛋白调节的。含有鸟苷敏感活性的组分被发现在钙敏感组分中含有一种抑制基础和钙刺激的腺苷环化酶的因子。在60℃加热和胰酶孵育可使该抑制物失活。抑制作用不是时间依赖性的，也不是由于磷酸二酯酶对cAMP的破坏，也不是由于ATPase对ATP的破坏。抑制作用不能被钙调蛋白逆转，因此它似乎不是钙调蛋白结合蛋白。蔗糖密度梯度沉淀法测得该缓蚀剂的沉降系数为4S，与对GPP(NH)p和NaF敏感的腺苷环化酶共沉淀。
Abstract: Adenylate cyclase was solubilized from washed paniculate fraction of rabbit cerebral cortex with the nonionic detergent Lubrol 12A9 and subjected to either gel filtration on Ultrogel AcA 34 or chromatography on DEAE Bio‐Gel A. By both procedures the enzyme was resolved into two components, one insensitive to guanyl 5′‐yl imidodiphosphate [Gpp(NH)p] and NaF but stimulated by Ca2+ and calmodulin, and another that was sensitive to Gpp(NH)p and NaF but relatively insensitive to Ca2+ and calmodulin. The data support the possibility that two independent forms of adenylate cyclase exist in cerebral cortex, one regulated by guanine nucleotide regulatory protein and another by Ca2+‐calmodulin. Fractions containing the guanylnucleotide‐sensitive activity were found to contain a factor that inhibited basal and Ca2+‐stimulated adenylate cyclase in the Ca2+‐sensitive fraction. The inhibitor was inactivated by heating at 60°C and by incubation with trypsin. Inhibition was not time‐dependent, and it was not due to destruction of cAMP by phosphodiesterase or of ATP by ATPase. Inhibitory action was not reversed by calmodulin and therefore it does not appear to be a calmodulin binding protein. Sucrose density gradient sedimentation indicated a sedimentation coefficient of 4S for the inhibitor; by this technique it co‐sedimented with the adenylate cyclase sensitive to Gpp(NH)p and NaF.