N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russia.
Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, Russia; State Research Center for Applied Microbiology and Biotechnology, Obolensk, Moscow Region, Russia.
Carbohydr Res. 2021 Nov;509:108439. doi: 10.1016/j.carres.2021.108439. Epub 2021 Sep 7.
K87 capsular polysaccharide (CPS) was isolated from Acinetobacter baumannii isolate LUH5547 that carries the KL87 capsule biosynthesis gene cluster at the chromosomal K locus. Studies by sugar analysis, selective chemical cleavages, and 1D and 2D H and C NMR spectroscopy showed that the CPS has a branched heptasaccharide repeat (K unit) containing one residue each of d-glucose (d-Glсp), d-glucuronic acid (d-GlсpA), N-acetyl-d-glucosamine (d-GlсpNAc), 6-deoxy-l-talose (l-6dTalp), and three residues of l-rhamnose (l-Rhap). The following structure of the CPS was established: →3)-α-L-Rhap-(1→2)-α-L-Rhap-(1→3)-α-L-6dTalp-(1→3)-β-D-GlcpNAc-(1→2↑1β-D-GlcpA-(4←1)-α-D-Glcp(2←1)-α-L-Rhap The position of a minor O-acetyl group present in the CPS was not determined. Functions of enzymes coded by genes in the KL87 gene cluster were tentatively assigned and found to be consistent with the CPS structure.
K87 荚膜多糖（CPS）从携带 KL87 荚膜生物合成基因簇的鲍曼不动杆菌 LUH5547 中分离得到，该基因簇位于染色体 K 位上。通过糖分析、选择性化学裂解以及 1D 和 2D H 和 C NMR 光谱研究表明，CPS 具有支化的七糖重复（K 单元），每个单元含有一个 d-葡萄糖（d-Glсp）、d-葡萄糖醛酸（d-GlсpA）、N-乙酰-d-葡萄糖胺（d-GlсpNAc）、6-去氧-l-塔罗糖（l-6dTalp）和三个 l-鼠李糖（l-Rhap）残基。CPS 的结构如下：→3）-α-L-Rhap-（1→2）-α-L-Rhap-（1→3）-α-L-6dTalp-（1→3）-β-D-GlcpNAc-（1→2↑1β-D-GlcpA-（4←1）-α-D-Glcp（2←1）-α-L-Rhap。CPS 中存在的一个 O-乙酰基的位置未确定。KL87 基因簇中基因编码的酶的功能被推测，并与 CPS 结构一致。
