Demonstration and characterization of partial glyceride specific lipases in pig thyroid plasma membranes.
Demonstration and characterization of partial glyceride specific lipases in pig thyroid plasma membranes.
复制标题
猪甲状腺质膜中偏甘油酯特异性脂肪酶的论证和表征。
DOI：
10.1016/0006-291x(80)90330-7
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发表时间：
1980
影响因子：
3.1
通讯作者：
Y. Kondo
中科院分区：
文献类型：
--
作者：
Y. Igarashi;Y. Kondo
用细菌磷脂酶C对纯化的猪甲状腺质膜进行处理，磷脂被水解制得甘油二酯和甘油单酯。然而，在孵育的后期，产物明显减少，这表明膜中存在降解部分甘油酯的脂肪酶。利用外源底物证明了脂肪酶(S)的存在。与普通脂肪酶不同的是，质膜酶不能水解三酰甘油，而能水解二酰甘油。该酶对1，2-二酰甘油的表观Km为1.25 mM，最适pH为7~7.5。膜对2-单酰基甘油也有一定的水解性，但对1-单酰基甘油没有水解性。在此基础上，我们提出了酶(S)参与促甲状腺激素作用下磷脂酰肌醇(PI)合成花生四烯酸的方案。
Purified pig thyroid plasma membranes were treated with bacterial phospholipase C. Phospholipids were hydrolyzed, producing diacylglycerols and monoacylglycerol. The products, however, decreased appreciably in the later period of incubation, suggesting the presence of lipase hydrolyzing partial glycerides in the membranes. The presence of the lipase(s) was proved by the use of exogenous substrates. In contrast to ordinary lipases, the plasma membrane enzyme did not hydrolyze triacylglycerol, but diacylglycerol. Apparent Km of the enzyme for 1,2-diacylglycerol was 1.25 mM and optimal pH, 7 – 7.5. The membranes also had the activity to hydrolyze 2-monoacylglycerol but not 1-monoacylglycerol. On the basis of these results, we proposed a scheme in which the enzyme(s) participate in arachidonic acid production from phosphatidylinositol (PI) under the influence of thyrotropin.