Friedberg S J, Heifetz A
Biochemistry. 1975 Feb 11;14(3):570-4. doi: 10.1021/bi00674a017.
Previous studies from this laboratory on the mechanism of O-alkyl bond formation using a microsomal system from Tetrahymena pyriformis have shown that O-alkyl lipid synthesized from dihydroxyacetone phosphate has exchanged one hydrogen stereospecifically from the 1-sn position of the glycerol moiety. Indirect evidence suggested that acyldihydroxyacetone phosphate, an intermediate in )-alkyl lipid synthesis, is probably not the locus of the exchange. In the present study in was shown that stable acyldihydroxyacetone phosphate incubated in the presence of tritiated water and Tetrahymena microsomes does not become tritiated. When hexadecanol is added to the system O-alkyl lipid is produced which has incorporated one atom of hydrogen for each mole of hexadecanol at all time periods examined. Experiments in Ehrlich ascites tumor cells have shown that the hydrogen exchange also occurs in a mammalian system. The results indicate that the mechanism of O-alkyl lipid ether bond formation involves a hydrogen exchange and that this exchange occurs after the formation of acyldihydroxyacetone phosphate.
该实验室先前利用梨形四膜虫微粒体系统对O-烷基键形成机制进行的研究表明，由磷酸二羟丙酮合成的O-烷基脂质已从甘油部分的1-sn位立体定向地交换了一个氢原子。间接证据表明，酰基磷酸二羟丙酮作为O-烷基脂质合成的中间体，可能不是氢交换的位点。在本研究中发现，在含有氚化水和四膜虫微粒体的条件下孵育的稳定酰基磷酸二羟丙酮并未被氚化。当向该系统中加入十六醇时，在所有检测时间段内，每摩尔十六醇都会产生一摩尔结合了一个氢原子的O-烷基脂质。对艾氏腹水瘤细胞进行的实验表明，氢交换在哺乳动物系统中也会发生。结果表明，O-烷基脂质醚键形成的机制涉及氢交换，且这种交换发生在酰基磷酸二羟丙酮形成之后。
