Evidence for the presence of multiple forms of Sph kinase in human platelets
Evidence for the presence of multiple forms of Sph kinase in human platelets
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DOI：
10.1042/bj3350301
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发表时间：
1998-10-15
影响因子：
4.1
通讯作者：
Nozawa, Y
中科院分区：
文献类型：
--
作者：
Banno, Y;Kato, M;Nozawa, Y
研究了人血小板中鞘氨醇（Sph）激酶活性的细胞内分布。总活性的一个大比例（72%）被认为是与膜馏分，和膜相关馏分具有较高的比活性相比，胞质酶。大部分的膜相关活性可以用1 M NaCl提取。热处理后，细胞溶质活性不稳定，在45 ℃孵育1小时期间，80%的活性丧失，而NaCl可提取部分在相同条件下稳定。当进行Mono Q柱层析时，胞质组分产生两个活性峰，NaCl可提取组分产生一个峰。这三种Sph激酶活性对β-辛基葡萄糖苷的刺激和N，N-二甲基鞘氨醇和L-苏型-二氢鞘氨醇的抑制表现出不同的反应，表明人血小板中存在多种酶形式。
The intracellular distribution of sphingosine (Sph) kinase activity was examined in human platelets. A large proportion (72%) of the total activity was found to be associated with the membrane fraction, and the membrane-associated fraction had higher specific activity compared with the cytosolic enzyme. Most of the membrane-associated activity could be extracted with 1 M NaCl. The cytosolic activity was unstable upon heat treatment, with 80%, Of the activity being lost during incubation at 45 degrees C for 1 h, whereas the NaCl-extractable fraction was stable under the same conditions. When subjected to Mono Q column chromatography, the cytosolic fraction produced two activity peaks and the NaCl-extractable fraction gave a single peak. These three Sph kinase activities showed different responses to stimulation by beta-octylglucoside and inhibition by N,N-dimethylsphingosine and L-threo-dihydrosphingosine, suggesting the presence of multiple enzyme forms in human platelets.