Lee T C, Kirk P, Snyder F
Biochim Biophys Acta. 1986 Jan 3;875(1):129-32. doi: 10.1016/0005-2760(86)90020-2.
Alkyl and alk-1-enyl (plasmalogens) ether-linked glycerolipids are prominent components of many mammalian cells; moreover, an acetylated form of an alkyl phospholipid was recently found to possess potent hypotensive, inflammatory and allergic properties. In our studies, preputial glands of mice were selected as a model to investigate the regulation of factors involved in the biosynthesis of ether-linked lipids, since these glands contain high concentrations of ether-linked neutral lipids that are under the influence of hormonal control. We found that a key enzyme in the ether-lipid metabolic pathway, microsomal acyl-CoA reductase that catalyzes the formation of long-chain fatty alcohols (precursor of the O-alkyl chain), was increased 16-fold after injecting testosterone into male, castrated mice. This induction was highly specific, since testosterone did not affect another microsomal enzyme, NADPH-cytochrome c reductase. Based on kinetics of enzyme activity changes, the half-life of acyl-CoA reductase was calculated to be 61-70 h. In addition, the activity of a cytosolic stimulatory protein for the acyl-CoA reductase (but not for a different cytosolic protein, lactate dehydrogenase) was also enhanced in the testosterone-treated, male, castrated mice. These findings indicate that acyl-CoA reductase is an important regulatory enzyme in the reactions that lead to the formation of the ether bond in glycerolipids and that it is modulated through hormonal control.
烷基和烯丙基（缩醛磷脂）醚键连接的甘油脂质是许多哺乳动物细胞的主要成分；此外，最近发现一种乙酰化形式的烷基磷脂具有强大的降压、抗炎和抗过敏特性。在我们的研究中，选择小鼠的包皮腺作为模型来研究参与醚键连接脂质生物合成的因子的调控，因为这些腺体含有高浓度的受激素控制的醚键连接中性脂质。我们发现，醚脂代谢途径中的一种关键酶，微粒体酰基辅酶A还原酶，催化长链脂肪醇（O-烷基链的前体）的形成，在给去势雄性小鼠注射睾酮后增加了16倍。这种诱导具有高度特异性，因为睾酮不影响另一种微粒体酶，NADPH-细胞色素c还原酶。根据酶活性变化的动力学，酰基辅酶A还原酶的半衰期计算为61-70小时。此外，在经睾酮处理的去势雄性小鼠中，酰基辅酶A还原酶的胞质刺激蛋白（而非另一种胞质蛋白乳酸脱氢酶）的活性也增强。这些发现表明，酰基辅酶A还原酶是甘油脂质中醚键形成反应中的一种重要调节酶，并且它通过激素控制进行调节。
