Characterization of essential enzyme sulfhydryl groups of thyroxine 5'-deiodinase from rat kidney.
Characterization of essential enzyme sulfhydryl groups of thyroxine 5'-deiodinase from rat kidney.
复制标题
大鼠肾脏甲状腺素 5-脱碘酶必需酶巯基的表征。
作者：
J. L. Leonard;I. Rosenberg
T4 5′-脱碘酶存在于肾和肝细胞膜中，是一种受丙硫脲嘧啶（PTU）抑制的巯基依赖性酶。在无预处理试剂的情况下，用PTU （10 μm）预处理酶活性肾膜制剂（Mx），并在N2条件下增加L-T4浓度，导致持续抑制程度增加。在L-T4存在或不存在的情况下，PTU有氧预处理导致80%的T4 5 ' -脱碘抑制。用碘乙酸或乙甲基马来酰亚胺对肾Mx进行巯基修饰，不可逆地灭活T4 5 ' -脱碘酶。发现可逆ptu -酶复合物的形成可保护T4 5 ' -脱碘免受碘乙酸或n -乙基马来酰亚胺的不可逆失活。大鼠注射[35S]硫脲嘧啶（TU）后，肾脏Mx中35S含量呈剂量依赖性增加，同时注射甲巯咪唑可使Mx中35S含量降低4倍。治疗肾Mx，含binding；国际空间站，10毫米…
T4 5′-deiodinase, found in cell membranes of kidney and liver, is a thiol-dependent enzyme inhibited by propylthiouracil (PTU). Pretreatment of enzymatically active kidney membrane preparations (Mx) with PTU (10 μm) and increasing concentrations of L-T4 under N2 resulted in increasing degrees of persistent inhibition, as assayed in the absence of pretreatment reagents. Aerobic pretreatment with PTU in the presence or absence of L-T4 resulted in 80% inhibition of T4 5′-deiodination. Sulfhydryl modification of kidney Mx with iodoacetate or Nethylmaleimide irreversibly inactivated T4 5′-deiodinase. The formation of a reversible PTU-enzyme complex was found to protect T4 5′-deiodination from irreversible inactivation by iodoacetate or N-ethylmaleimide. A dose-dependent increase in the 35S content of kidney Mx was found after injection of [35S]thiouracil (TU) into rats, and the Mx 35S content was reduced 4-fold by simultaneous injection of methimazole. Treatment of kidney Mx, containing bound ;ISS, with 10 mm ...
DOI：
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发表时间：
1978-07
期刊：
The Journal of biological chemistry
影响因子：
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作者：
W. Agnew;G. Popják
通讯作者：
W. Agnew;G. Popják