Reddy G P, Hayat U, Xu Q, Reddy K V, Wang Y, Chiu K W, Morris J G, Bush C A
Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore 21250, USA.
Eur J Biochem. 1998 Jul 1;255(1):279-88. doi: 10.1046/j.1432-1327.1998.2550279.x.
Vibrio vulnificus is a pathogenic gram-negative bacterium, endemic to brackish waters, which is often isolated from sediments, from the water column or from shellfish. It is associated with wound infections and septicemia in humans and the virulence of V. vulnificus has been strongly associated with encapsulation. The capsular polysaccharide purified from a virulent strain of V. vulnificus 6353 did not show cross reactivity with antibodies to the capsular polysaccharide of a related pathogenic strain of V. vulnificus (MO6-24) the structure of which was recently reported. NMR spectroscopic analysis of the purified polysaccharide from strain 6353 showed that the polymer is composed of four sugar residues per repeating subunit including 2,6-dideoxy-2-N-acetylamino-alpha-D-glucose (QuiNAc), 2-deoxy-2-N-acetylamino-alpha-D-galactose (alpha-D-GalNAc), 2-deoxy-2-N-acetylamino-alpha-D-galcturonic acid (alpha-D-GalNAcA) and 2-N-acetylamino-alpha-D-glucuronamide (alpha-D-GlcNAcANH2). The 1H- and 13C-NMR spectra were completely assigned by homonuclear and heteronuclear NMR spectroscopy. Sugar types and anomeric configurations were determined from proton homonuclear coupling constants and glycosidic linkages were determined from 1H-13C heteronuclear multiple bond correlation spectra. Sugar identities were confirmed by high performance anion-exchange chromatography and absolute configurations were determined by gas chromatography in combination with molecular modeling and NMR spectroscopy. The structure of the polysaccharide repeating unit is: [-->4)-alpha-D-GalpNAc-(1-->3)-alpha-D-GalpNAcA-(1-->3)-alpha-D-++ +QuipNAc-(1-->]n alpha-D-GlcpNAcANH2 (1-->4)- -->. While there are some common features shared among the structures of the capsular polysaccharides of pathogenic strains of V. vulnificus, there are distinct differences in the detailed structures.
创伤弧菌是一种致病性革兰氏阴性菌，在咸淡水中呈地方性流行，常从沉积物、水柱或贝类中分离得到。它与人类伤口感染和败血症有关，创伤弧菌的毒力与荚膜形成密切相关。从创伤弧菌6353强毒株中纯化的荚膜多糖与最近报道其结构的相关致病菌株（MO6 - 24）的荚膜多糖抗体没有交叉反应。对6353菌株纯化多糖的核磁共振光谱分析表明，该聚合物每个重复亚基由四个糖残基组成，包括2,6 - 二脱氧 - 2 - N - 乙酰氨基 - α - D - 葡萄糖（QuiNAc）、2 - 脱氧 - 2 - N - 乙酰氨基 - α - D - 半乳糖（α - D - GalNAc）、2 - 脱氧 - 2 - N - 乙酰氨基 - α - D - 半乳糖醛酸（α - D - GalNAcA）和2 - N - 乙酰氨基 - α - D - 葡萄糖醛酰胺（α - D - GlcNAcANH2）。通过同核和异核核磁共振光谱完全归属了1H - 和13C - NMR谱。根据质子同核耦合常数确定糖的类型和异头构型，根据1H - 13C异核多键相关光谱确定糖苷键。通过高效阴离子交换色谱确认糖的身份，并通过气相色谱结合分子建模和核磁共振光谱确定绝对构型。多糖重复单元的结构为：[-->4)-α - D - GalpNAc-(1-->3)-α - D - GalpNAcA-(1-->3)-α - D - ++ +QuipNAc-(1-->]n α - D - GlcpNAcANH2 (1-->4)- -->。虽然创伤弧菌致病菌株的荚膜多糖结构有一些共同特征，但在详细结构上存在明显差异。
