Research Center Borstel, Leibniz-Center for Medicine and Biosciences, Parkallee 1-40, D-23845 Borstel, Germany.
Carbohydr Res. 2013 Aug 30;378:63-70. doi: 10.1016/j.carres.2013.05.003. Epub 2013 May 15.
In Acinetobacter calcoaceticus NCTC 10305 and A. haemolyticus NCTC 10305 lipopolysaccharide (LPS) a Kdo (3-deoxy-D-manno-oct-2-ulosonic acid)-related octulosonic acid (Ko) interlinks the lipid A with the core-oligosaccharide. This Ko replaces the first Kdo (Kdo(I)) attached to the lipid A backbone in the LPS. The only structural difference between Kdo and Ko is the 3-hydroxylation. After the discovery of the final step in Ko-biosynthesis it is now generally accepted that Ko is structurally related to Kdo, although a final proof so far is lacking. In the present paper we describe the stereochemical determination of the natural Ko isolated from the LPS of A. calcoaceticus NCTC 10305 by chemical, mass spectrometry (MS), and (1)H and (13)C NMR spectroscopy. Our results show that in A. calcoaceticusd-glycero-α-D-talo-oct-2-ulopyranosonic acid (DgαDt-Kop) represents the Kdo-related sugar interlinking the core-oligosaccharide and the lipid A backbone.
在醋酸钙不动杆菌 NCTC 10305 和溶血不动杆菌 NCTC 10305 的脂多糖 (LPS) 中，Kdo（3-脱氧-D-甘露辛-2-酮酸）相关的辛酮酸 (Ko) 将脂质 A 与核心寡糖连接起来。这种 Ko 取代了 LPS 中连接到脂质 A 主链上的第一个 Kdo（Kdo(I)）。Kdo 和 Ko 之间唯一的结构差异是 3-羟基化。在发现 Ko 生物合成的最后一步后，现在普遍认为 Ko 在结构上与 Kdo 相关，尽管目前还缺乏最终的证据。在本文中，我们通过化学、质谱 (MS) 和 (1)H 和 (13)C NMR 光谱学描述了从醋酸钙不动杆菌 NCTC 10305 的 LPS 中分离出的天然 Ko 的立体化学测定。我们的结果表明，在醋酸钙不动杆菌中，d-甘油-α-D-塔罗辛-oct-2-吡喃酮酸 (DgαDt-Kop) 代表连接核心寡糖和脂质 A 主链的 Kdo 相关糖。
