首页> 美国卫生研究院文献>Biochemical Journal >The use of potent inhibitors of alkaline phosphatase to investigate the role of the enzyme in intestinal transport of inorganic phosphate.
【2h】

The use of potent inhibitors of alkaline phosphatase to investigate the role of the enzyme in intestinal transport of inorganic phosphate.

机译:使用有效的碱性磷酸酶抑制剂研究该酶在无机磷酸盐肠运输中的作用。

代理获取
本网站仅为用户提供外文OA文献查询和代理获取服务,本网站没有原文。下单后我们将采用程序或人工为您竭诚获取高质量的原文,但由于OA文献来源多样且变更频繁,仍可能出现获取不到、文献不完整或与标题不符等情况,如果获取不到我们将提供退款服务。请知悉。

摘要

In an investigation of the link between Pi transport and alkaline phosphatase in mammalian small intestine, the characteristics of Pi uptake by brush-border membrane vesicles prepared from rat intestine were compared with the properties of the tissue alkaline phosphatase. The NaCl-dependent Pi uptake had a Km of 0.1 mM at pH 7.5 and was inhibited totally by 1 mM-arsenate and by 1 mM-vanadate. These compounds are also potent competitive inhibitors of the alkaline phosphatase activity of the vesicles, with Ki values less than 5 microM at pH 7.5. When the effect on Pi uptake of several other potent inhibitors of alkaline phosphatase, including phosphonates and phosphate analogues, was tested, however, it was found that there was little, if any, inhibition of transport under conditions in which the inhibition of phosphatase activity was total. Incubation of the vesicles for 20 min with oxidized adenosine 5'-[beta gamma-imido]triphosphate followed by rapid gel filtration to remove the inhibitor resulted in an irreversible loss of phosphatase activity, but left Pi transport unimpaired. Conversely, a similar prolonged incubation with adenosine 5'-[beta-thio]diphosphate or adenosine 5'-[gamma-thio]triphosphate had no effect on alkaline phosphatase activity but resulted in a permanent partial loss of transport capability. The failure to demonstrate an inhibition of Pi transport resulting from inhibition of alkaline phosphatase and the different responses of enzymic activity and Pi transport to irreversible inhibition make it very unlikely that the enzyme is directly involved in the transport system.
机译:在研究哺乳动物小肠中Pi转运与碱性磷酸酶之间的联系时,比较了由大鼠肠制备的刷状边界膜囊泡对Pi吸收的特征与组织碱性磷酸酶的性质。 NaCl依赖的Pi吸收在pH 7.5时的Km为0.1 mM,并被1 mM砷酸盐和1 mM钒酸盐完全抑制。这些化合物也是囊泡碱性磷酸酶活性的有效竞争性抑制剂,在pH 7.5时Ki值小于5 microM。然而,当测试了其他几种碱性磷酸酶的强效抑制剂(包括膦酸酯和磷酸盐类似物)对Pi吸收的影响时,发现在抑制磷酸酶活性的条件下,几乎没有抑制转运的作用。总。将囊泡与氧化的腺苷5'-βγ-亚氨基三磷酸一起孵育20分钟,然后快速凝胶过滤以除去抑制剂,导致磷酸酶活性不可逆地损失,但使Pi运输不受损害。相反,用腺苷5'-β-硫代二磷酸或腺苷5'-γ-硫代三磷酸进行类似的长时间温育对碱性磷酸酶活性没有影响,但是导致永久的运输能力部分丧失。未能证明由于抑制了碱性磷酸酶而导致对Pi转运的抑制以及酶活性和Pi转运对不可逆抑制的不同响应,使得该酶不太可能直接参与转运系统。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
代理获取

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号