Kulshin V A, Zähringer U, Lindner B, Jäger K E, Dmitriev B A, Rietschel E T
Forschungsinstitut Borstel, Institut für Experimentelle Biologie und Medizin, Federal Republic of Germany.
Eur J Biochem. 1991 Jun 15;198(3):697-704. doi: 10.1111/j.1432-1033.1991.tb16069.x.
The structure of the lipid A component of lipopolysaccharides isolated from two wild-type strains (Fisher 2 and 7) and one rough mutant (PAC 605) of Pseudomonas aeruginosa was investigated using chemical analysis, methylation analysis, combined gas-liquid chromatography/mass spectrometry, laser-desorption mass spectrometry and NMR spectroscopy. The lipid A backbone was found to consist of a pyranosidic beta 1,6-linked D-glucosamine disaccharide [beta-D-GlcpN-(1----6)-D-GlcpN], phosphorylated in positions 4' and 1. Position 6' of the beta-D-GlcpN-(1----6)-D-GlcpN disaccharide was identified as the attachment site of the core oligosaccharide and the hydroxyl group at C-4 was not substituted. Lipid A of the three P. aeruginosa strains expressed heterogeneity with regard to the degree of acylation: a hexaacyl as well as a pentaacyl component were structurally characterized. The hexaacyl lipid A contains two amide-bound 3-O-acylated (R)-3-hydroxydodecanoic acid groups [12:0(3-OH)] at positions 2 and 2' of the GlcN dissacharide and two ester-bound (R)-3-hydroxydecanoic acid groups [10:0(3-OH)] at positions 3 and 3'. The pentaacyl species, which represents the major lipid A component, lacks one 10:0(3-OH) residue, the hydroxyl group in position 3 of the reducing GlcN residue being free. In both hexa- and pentaacyl lipid A the 3-hydroxyl group of the two amide-linked 12:0(3-OH) residues are acylated by either dodecanoic (12:0) or (S)-2-hydroxydodecanoic acid [12:0(2-OH)], the lipid A species with two 12:0(2-OH) residues, however, being absent. The presence of only five acyl residues in the major lipid A fraction may account for the low endotoxic activity observed with P. aeruginosa lipopolysaccharide.
利用化学分析、甲基化分析、气液色谱/质谱联用、激光解吸质谱和核磁共振光谱法，对从铜绿假单胞菌的两株野生型菌株（费舍尔2型和7型）及一株粗糙突变体（PAC 605）中分离出的脂多糖的脂质A成分结构进行了研究。发现脂质A主链由一个吡喃糖型的β1,6-连接的D-葡糖胺二糖[β-D-GlcpN-(1→6)-D-GlcpN]组成，在4'和1位磷酸化。β-D-GlcpN-(1→6)-D-GlcpN二糖的6'位被确定为核心寡糖的连接位点，C-4位的羟基未被取代。三株铜绿假单胞菌菌株的脂质A在酰化程度上表现出异质性：对一种六酰基成分和一种五酰基成分进行了结构表征。六酰基脂质A在GlcN二糖的2和2'位含有两个酰胺键连接的3-O-酰化的（R）-3-羟基十二烷酸基团[12:0(3-OH)]，在3和3'位含有两个酯键连接的（R）-3-羟基癸酸基团[10:0(3-OH)]。代表主要脂质A成分的五酰基种类缺少一个10:0(3-OH)残基，还原型GlcN残基3位的羟基是游离的。在六酰基和五酰基脂质A中，两个酰胺连接的12:0(3-OH)残基的3-羟基被十二烷酸（12:0）或（S）-2-羟基十二烷酸[12:0(2-OH)]酰化，然而，含有两个12:0(2-OH)残基的脂质A种类不存在。主要脂质A组分中仅存在五个酰基残基，这可能是铜绿假单胞菌脂多糖内毒素活性较低的原因。
