A sensitive assay of GTP cyclohydrolase I activity in rat and human tissues using radioimmunoassay of neopterin.
A sensitive assay of GTP cyclohydrolase I activity in rat and human tissues using radioimmunoassay of neopterin.
复制标题
使用新蝶呤放射免疫测定法对大鼠和人体组织中 GTP 环水解酶 I 活性进行灵敏测定。
DOI：
10.1016/0003-2697(86)90537-3
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发表时间：
1986
影响因子：
2.9
通讯作者：
T. Nagatsu
中科院分区：
文献类型：
--
作者：
M. Sawada;T. Horikoshi;M. Masada;M. Akino;T. Sugimoto;S. Matsuura;T. Nagatsu
用放射免疫分析法建立了一种高灵敏、简便的测定GTP环化水解酶I活性的方法。通过GTP环化水解酶I由GTP形成的d-溴-7，8-二氢新蝶呤三磷酸被碘氧化并被碱性磷酸酶脱磷酸化为d-溴-新蝶呤，并通过放射免疫测定法定量d-溴-新蝶呤。该方法灵敏度高，仅需0.2 mg大鼠肝组织即可测定活性。该方法重现性好，可用于多个样品的同时测定。在几种大鼠组织中测定GTP环化水解酶I的活性。例如，大鼠纹状体（n = 5）中的酶活性为13.7 ± 1.5 pmol/mg蛋白/小时（平均值± SE），与高效液相色谱荧光检测法所得结果一致。首次用这种新方法测定了尸检人脑（尾状核）的活性。帕金森病患者（n = 6）尾状核的活性为0.82 ± 0.56pmol/mg蛋白/h，明显低于对照组（n = 10）的4.22 ± 0.43pmol/mg蛋白/h。
A highly sensitive and simple assay for the activity of GTP cyclohydrolase I (EC 3.5.4.16) was established using a newly developed radioimmunoassay. d-erythro-7,8-Dihydroneopterin triphosphate formed from GTP by GTP cyclohydrolase I was oxidized by iodine and dephosphorylated by alkaline phosphatase to d-erythro-neopterin, and quantified by a radioimmunoassay for d-erythro-neopterin. This method was highly sensitive and required only 0.2 mg of rat liver tissues for the measurement of the activity. It was reproducible and can be applied for the simultaneous assay of many samples. The activity of GTP cyclohydrolase I was measured in several rat tissues. For example, the enzyme activity in rat striatum (n = 5) was 13.7 ± 1.5 pmol/mg protein per hour (mean ± SE), and agreed well with those obtained by high-performance liquid chromatography with fluorescence detection. The activity in the autopsy human brains (caudate nucleus) was measured by this new method for the first time. The activity in the caudate nucleus from parkinsonian patients (n = 6) was 0.82 ± 0.56 pmol/mg protein per hour which was significantly lower than the control value, 4.22 ± 0.43 pmol/mg protein per hour (n = 10).