Kuri-Harcuch W, Green H
J Biol Chem. 1977 Mar 25;252(6):2158-60.
When preadipose 3T3 cells pass from growing to resting state, they increase their rate of synthesis of triacylglycerol from precursors and convert to adipose cells. The behavior of two enzymes involved in the synthesis of triacylglycerol, glycerophosphate acyltransferase, and malic enzyme have been examined during the adipose conversion of 3T3-F442A in surface culture and in suspension culture stabilized with methylcellulose. Glycerophosphate acyltransferase activity rises sharply during the conversion and reaches a level of 80 times higher than that of another 3T3 subline in which practically no adipose conversion takes place (3T3-C2). The activity of malic enzyme also rises during the adipose conversion of 3T3-F442A and reaches a level of 15-fold higher than that of 3T3-C2. The activity of glycerophosphate acyltransferase responds more sharply than that of malic enzyme but the rise in activity is not sustained as long, so that the relative levels of the two enzymes change during the conversion. The adipose conversion appears to be the result of increases in the activity of the synthesizing enzymes, brought about by either of the two most physiological methods available for arresting the growth of cultured cells.
当脂肪前体细胞3T3从生长状态转变为静止状态时，它们从前体合成三酰甘油的速率会增加，并转化为脂肪细胞。在表面培养以及用甲基纤维素稳定的悬浮培养中，对3T3-F442A脂肪转化过程中涉及三酰甘油合成的两种酶，即甘油磷酸酰基转移酶和苹果酸酶的行为进行了研究。在转化过程中，甘油磷酸酰基转移酶的活性急剧上升，达到的水平比另一个几乎不发生脂肪转化的3T3亚系（3T3-C2）高80倍。在3T3-F442A脂肪转化过程中，苹果酸酶的活性也会上升，达到比3T3-C2高15倍的水平。甘油磷酸酰基转移酶的活性比苹果酸酶的活性反应更迅速，但活性上升持续的时间不长，因此在转化过程中这两种酶的相对水平会发生变化。脂肪转化似乎是由两种最常见的用于阻止培养细胞生长的生理方法之一导致的合成酶活性增加的结果。
