Tyhach R J, Engel R, Tropp B E
J Biol Chem. 1976 Nov 10;251(21):6717-23.
3,4-Dihydroxy[3-(3)H]butyl-1-phosphonate, and analogue of glycerol 3-phosphate, is incorporated into a very polar lipid material by cultures of Escherichia coli strain 8 and in vitro by CDP-diglyceride:sn-glycerol-3-phosphate phosphatidyltransferase. These labeled lipids have been fractionated by column chromatography on DEAE-cellulose, revealing that only one labeled compound is formed in vitro, while four are synthesized in vivo. The main component of the material formed by intact cells has been shown to be identical with that produced enzymatically. This species has been identified as the phosphonic acid analogue of phosphatidylglycerophosphate [(1,2-diacyl)-sn-glyceryl-D-4'-phosphoryloxy-3'-hydroxybutyl-1'-phosphonate]. Hydrolysis of this novel lipid with phospholipase C resulted in the production of diglyceride and a water-soluble derivative of 3,4-dihydroxybutyl-1-phosphonate and inorganic phosphate in a molar ratio of 1.03/1. Enzymatic analysis of the phosphonate liberated in this manner showed it to be the D enantiomer, thereby confirming the proposed structure of the lipid analogue. The analogue of phosphatidylglycerophosphate did not turn over and appeared to have no precursor-product relationship to the other labeled lipids derived from 3,4-dihydroxy[3-(3)H]butyl-1-phosphonate in vivo. Analysis of the other three labeled products revealed the tritium to be present on glycerol 3-phosphate and not intact phosphonate, indicating some metabolic degradation of the latter. Examination of cell components other than lipids revealed little incorporation of label, while a significant amount of tritium was found to be present in a distillable form, 3H2O. Experiments with mutants of E. coli lacking the known glycerol-3-phosphate dehydrogenases indicated that these enzymes are not responsible for the removal of tritium from from 3,4-dihydroxy[3-(3)H]butyl-1-phosphonate in vivo. Indirect evidence suggests that the inhibition of cell growth by this analogue is not due to its catabolic products.
3,4-二羟基[3-(³H)]丁基-1-膦酸酯，作为甘油3-磷酸酯的类似物，可被大肠杆菌8菌株的培养物整合到一种极性很强的脂质物质中，并且在体外可被CDP-二甘油酯：sn-甘油-3-磷酸磷脂酰转移酶整合。这些标记的脂质已通过DEAE-纤维素柱色谱法进行了分离，结果显示在体外仅形成一种标记化合物，而在体内合成了四种。完整细胞形成的物质的主要成分已被证明与酶促产生的物质相同。该物质已被鉴定为磷脂酰甘油磷酸酯的膦酸类似物[(1,2-二酰基)-sn-甘油-D-4'-磷酸氧基-3'-羟基丁基-1'-膦酸酯]。用磷脂酶C水解这种新型脂质会产生甘油二酯以及3,4-二羟基丁基-1-膦酸酯的水溶性衍生物和无机磷酸盐，其摩尔比为1.03/1。对以这种方式释放的膦酸酯进行酶促分析表明它是D型对映体，从而证实了所提出的脂质类似物的结构。磷脂酰甘油磷酸酯的类似物不会周转，并且在体内似乎与源自3,4-二羟基[3-(³H)]丁基-1-膦酸酯的其他标记脂质没有前体-产物关系。对其他三种标记产物的分析表明，³H存在于甘油3-磷酸酯上，而不是完整的膦酸酯上，这表明后者发生了一些代谢降解。对除脂质以外的细胞成分进行检查发现几乎没有标记物的掺入，而发现大量的³H以可蒸馏形式³H₂O存在。对缺乏已知甘油-3-磷酸脱氢酶的大肠杆菌突变体进行的实验表明，这些酶在体内并不负责从3,4-二羟基[3-(³H)]丁基-1-膦酸酯中去除³H。间接证据表明这种类似物对细胞生长的抑制不是由于其分解代谢产物。
