Biosynthetic mechanism of sn-2,3-di-O-phytanylglycerol, core membrane lipid of the archaebacterium Halobacterium halobium
Biosynthetic mechanism of sn-2,3-di-O-phytanylglycerol, core membrane lipid of the archaebacterium Halobacterium halobium
复制标题
古细菌盐杆菌核心膜脂sn-2,3-di-O-植烷甘油的生物合成机制
DOI：
10.1021/ja00163a041
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发表时间：
1990
影响因子：
15
通讯作者：
T. Oshima
中科院分区：
文献类型：
--
作者：
K. Kakinuma;M. Yamagishi;Y. Fujimoto;N. Ikekawa;T. Oshima
通过向培养物中加入180标记的甘油、手性氘代甘油和氘代葡萄糖，并随后对同位素富集的2，3-二植烷基甘油进行13 C、* H和2 H NMR分析，研究了古细菌Halobacterium halobium的膜核心脂质的生物合成机制。80-chase实验表明，甘油的sn-C-3氧原子最终保留在xn-2，3-二植烷基甘油中。甘油，从而表明其在醚形成反应中的亲核性质。葡萄糖的C-6和甘油的sn-C-3有效地立体专一性地置换到脂质的sn-C-位，这强烈地暗示：（1）Entner-Doudoroff途径在H.（2）甘油的C-2位明显发生立体化学转化，形成2，3-二-O-烷基化脂质。C-2氢的Chase研究进一步表明氧化和还原过程是导致甘油部分C-2处构型反转的原因。真细菌、真核生物和古细菌质膜中主要脂类的化学差异引起了化学、生物化学和进化研究的广泛关注。[1]古细菌细胞中磷脂和糖脂的核心脂质sn-2，3-二-O-烷基化甘油的结构最显著，在其n-C-1位上具有极性头基，如方案I所示，[2]而真细菌和真核细胞的主要脂质主要由在其sn-C-3位上携带极性头基的sn-1，2-二-O-酰基甘油组成。古细菌脂类及其代谢产物的生物合成已在不同的实验室进行了广泛的研究。Kates等人做出了重大贡献，他们研究了专性嗜盐菌表皮嗜盐杆菌，3和DeRosa等人，他们对极端嗜酸菌硫化叶菌进行了研究，45678以及最近，Poulter等人，后两种细菌物种实际上含有联植烷基二甘油四醚的令人感兴趣的72元环结构作为主要的膜脂质，其生物合成前体被认为是1 N-2，3-O-二烷基化甘油。六、七
The biosynthetic mechanism of the membrane core lipid of the archaebacterium Halobacterium halobium was studied by feeding 180-labeled glycerol, chirally deuterated glycerol, and deuterated glucose to the culture, and subsequent 13C,* H, and 2H NMR analyses of the isotopically enriched 2, 3-di-Ophytanylglycerol. A, 80-chase experiment showed that the oxygen atom of sn-C-3 of glycerol is retained ultimately in xn-2, 3-di-Ophytanylg! ycerol, therebysuggesting its nucleophilic nature in the ether-forming reaction. Efficient and stereospecific incorporationof the C-6 of glucose and sn-C-3 of glycerol into the sn-C-position of the lipid strongly implied that (1) the Entner-Doudoroff pathway operates inH. halobium and (2) stereochemical inversion apparently takes place at the C-2 position of glycerol to form 2, 3-di-O-alkylated lipids. Chase studies of the C-2 hydrogen further suggested an oxidation and a reduction processes are responsible for the inversion of configuration at C-2 of the glycerol moiety. A stepwise alkylation mechanism is postulated.Chemical divergence of the major lipids in the plasma mem-brane of the usual eubacterial and eukaryotes cells and of the archaebacterial cells have attracted wide attention from chemical, biochemical, and evolutionary interests. 1 The structure of sn-2, 3-di-O-alkylated glycerol, the core lipid in phospholipids and glycolipids in archaebacterial cells, having a polar head group on the íh-C-1 position, is the most remarkable, as illustrated in Scheme I, 2 while the major lipids of the eubacterial and eukaryotic cells mostly consist of sn-1, 2-di-O-acylglycerol carrying a polar head group on its sn-C-3 position. Biosynthesis of archaebacterial lipids and related metabolites have been studied extensively at variouslaboratories. Major contributions were made by Kates et al., who have studied the obligate halophile Halobacterium cutirubrum, 3 and by DeRosa et al., who have undertaken studies with the extreme acidothermophile Sulfolobus sp., 4 5678and more recently, Poulter et al., who have reported the lipid biosynthesis of the methanogen Methanospirillum hungateir The latter two bacterial species actually contain an interesting 72-membered ring structure of biphytanyl diglycerol tetraether as a predominant membrane lipid, the biosynthetic precursor of which is believed to be in-2, 3-O-dial-kylated glycerol. 6, 7