Huterer S, Wherrett J
J Lipid Res. 1979 Nov;20(8):966-73.
To further elucidate the role of bis(monoacylglycero)phosphate in lysosomes, its metabolism was assessed by incubation of intact and disrupted macrophages in the presence of labeled lipid precursors. In rabbit pulmonary macrophages bis(monoacylglycero)P accounted for 17.9% and acylphosphatidylglycerol for 2.6% of phospholipid phosphorus. Major fatty acids in bis(monoacylglycero)P were oleic (47%), linoleic (29%), and arachidonic (6.4%); those in acylphosphatidylglycerol were of similar distribution except for a high content of palmitic acid (20%). When homogenates of rabbit pulmonary and peritoneal macrophages, rat pulmonary macrophages, and human blood leukocytes were incubated with sn[(14)C]glycerol-3-phosphate and CDP-diacylglycerol at pH 7.4, there was labeling of bis(monoacylglycero)P and acylphosphatidylglycerol that correlated with content of bis(monoacylglycero)P. When intact rabbit pulmonary macrophages were incubated for 60 min with [(3)H]glucose and [(32)P]orthophosphate, small amounts of label appeared in bis(monoacylglycero)P and only traces in acylphosphatidylglycerol. In contrast, incubation of intact cells with the (14)C-labeled fatty acid precursors palmitic, oleic, and arachidonic acids resulted in much greater labeling of the two lipids. Labeling of phospholipids was greatest with arachidonate as precursor and least with palmitate; after 60 min, labeling of bis(monoacylglycero)P with arachidonate was 10- and 50-fold greater than with oleate and palmitate, respectively, and was exceeded only by that of phosphatidylcholine. Calculated ratios of labeling of fatty acid to P, particularly those for arachidonate, were much greater for bis(monoacylglycero)P and for acylphosphatidylglycerol than for other phospholipids. This suggests a uniquely high turnover of fatty acids in bis(monoacylglycero)P and acylphosphatidylglycerol and thus a more specific role for these compounds in metabolism of complex lipids in the lysosome.-Huterer, S., and J. Wherrett. Metabolism of bis(monoacylglycero)phosphate in macrophages.
为了进一步阐明双（单酰甘油）磷酸酯在溶酶体中的作用，通过在标记的脂质前体存在下孵育完整和破碎的巨噬细胞来评估其代谢。在兔肺巨噬细胞中，双（单酰甘油）磷酸酯占磷脂磷的17.9%，酰基磷脂酰甘油占2.6%。双（单酰甘油）磷酸酯中的主要脂肪酸为油酸（47%）、亚油酸（29%）和花生四烯酸（6.4%）；酰基磷脂酰甘油中的脂肪酸分布相似，只是棕榈酸含量较高（20%）。当兔肺和腹膜巨噬细胞、大鼠肺巨噬细胞以及人血白细胞的匀浆在pH 7.4条件下与sn-[(14)C]甘油-3-磷酸和CDP-二酰甘油一起孵育时，双（单酰甘油）磷酸酯和酰基磷脂酰甘油出现标记，且与双（单酰甘油）磷酸酯的含量相关。当完整的兔肺巨噬细胞与[(3)H]葡萄糖和[(32)P]正磷酸盐一起孵育60分钟时，双（单酰甘油）磷酸酯中出现少量标记，而酰基磷脂酰甘油中仅有微量标记。相反，用(14)C标记的脂肪酸前体棕榈酸、油酸和花生四烯酸孵育完整细胞，导致这两种脂质的标记程度更高。以花生四烯酸为前体时磷脂的标记程度最高，以棕榈酸为前体时最低；60分钟后，用花生四烯酸标记双（单酰甘油）磷酸酯的程度分别比用油酸和棕榈酸高10倍和50倍，且仅低于磷脂酰胆碱。计算得出的脂肪酸与磷的标记比率，特别是花生四烯酸的比率，双（单酰甘油）磷酸酯和酰基磷脂酰甘油比其他磷脂高得多。这表明双（单酰甘油）磷酸酯和酰基磷脂酰甘油中脂肪酸的周转率极高，因此这些化合物在溶酶体中复合脂质的代谢中具有更特殊的作用。-胡特勒，S.，和J. 惠勒特。巨噬细胞中双（单酰甘油）磷酸酯的代谢
