The effects of phosphorylating conditions on tyrosine hydroxylase activity are influenced by assay conditions and brain region.
The effects of phosphorylating conditions on tyrosine hydroxylase activity are influenced by assay conditions and brain region.
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磷酸化条件对酪氨酸羟化酶活性的影响受到测定条件和脑区域的影响。
DOI：
10.1016/0024-3205(81)90416-1
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发表时间：
1981
期刊：
影响因子：
6.1
通讯作者：
Zigmond,MJ
中科院分区：
文献类型：
--
作者：
Acheson,AL;Kapatos,G;Zigmond,MJ
使用大鼠脑匀浆的上清液部分，我们研究了几个变量，这似乎是重要的酪氨酸羟化酶（TH）活性的研究。这些包括试验缓冲液的类型和pH值、辅因子浓度和脑区。我们观察到，在Tris-醋酸盐缓冲液中测定TH活性的最适pH因脑区而异。在所检查的区域中，最适范围为pH 5.7（纹状体）至pH 6.2（海马）。使用MES缓冲液获得了类似的结果，尽管TH活性在某些pH值下降低。最适pH值与这些脑区中去甲肾上腺素和多巴胺的相对比例无关。在亚饱和浓度的辅因子的存在下，在cAMP依赖的蛋白磷酸化条件下的TH的孵育增加TH活性显着在纹状体和海马。在磷酸化条件下产生的TH活性的增加是最明显的pH值以上的最佳pH值。结果进行了讨论，其影响在体外测量TH活性的改变。
Using the supernatant fraction of rat brain homogenates, we investigated several variables which appear to be important in studies of tyrosine hydroxylase (TH) activity. These included the type and pH of the assay buffer, cofactor concentration, and brain region. We observed that the pH optimum for TH activity assayed in Tris-acetate buffer varied with brain region. Among the regions examined, the optima ranged from pH 5.7 (striatum) to pH 6.2 (hippocampus). Similar results were obtained using MES buffer, although TH activity was reduced at certain pH values. The pH optimum was not correlated with the relative proportions of norepinephrine and dopamine in these brain regions. In the presence of a subsaturating concentration of cofactor, incubation of TH under cAMP-dependent protein phosphorylating conditions increased TH activity significantly in both striatum and hippocampus. The increase in TH activity produced by phosphorylating conditions was most pronounced at pH values above the pH optimum. The results are discussed in terms of their implications for in vitro measurement of alterations in TH activity.