葡萄糖和胰岛素对大鼠脂肪组织中脂蛋白脂肪酶激活及蛋白质合成的影响。
Effects of glucose and insulin on the activation of lipoprotin lipase and on protein-synthesis in rat adipose tissue.
作者信息
Parkin S M, Walker K, Ashby P, Robinson D S
出版信息
Biochem J. 1980 Apr 15;188(1):193-9. doi: 10.1042/bj1880193.
Glucose, and certain sugars that can readily be converted to glucose 6-phosphate, bring about an activation of adipose-tissue lipoprotein lipase when epididymal fat-bodies from starved rats are incubated in the presence of cycloheximide. Other substrates do not support the activation. If the tissue is preincubated in the presence of cycloheximide for longer than 2h, the ability of added glucose to activate the enzyme is lost. On the other hand, the addition of glucose still brings about an increase in lipoprotein lipase activity after preincubation in the absence of cycloheximide for as long as 4h. The magnitude of the increase in enzyme activity brought about by the addition of glucose is increased when protein synthesis is stimulated during the preincubation period by insulin. The results are interpreted in terms of the existence in adipose tissue of a proenzyme pool of lipoprotein lipase that is normally maintained by protein synthesis and that is converted to complete enzyme of higher specific activity by a process that specifically requires glucose.
当饥饿大鼠的附睾脂肪体在放线菌酮存在的情况下进行孵育时，葡萄糖以及某些能够迅速转化为6-磷酸葡萄糖的糖类，会引发脂肪组织脂蛋白脂肪酶的激活。其他底物则无法支持这种激活作用。如果组织在放线菌酮存在的情况下预孵育超过2小时，添加葡萄糖激活该酶的能力就会丧失。另一方面，在不存在放线菌酮的情况下预孵育长达4小时后，添加葡萄糖仍会导致脂蛋白脂肪酶活性增加。当在预孵育期间通过胰岛素刺激蛋白质合成时，添加葡萄糖所引起的酶活性增加幅度会增大。这些结果被解释为脂肪组织中存在脂蛋白脂肪酶的酶原池，该酶原池通常通过蛋白质合成来维持，并且通过一个特别需要葡萄糖的过程转化为具有更高比活性的完整酶。
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