Structural Properties of the Lipid A Component of the Lipopolysaccharide(Endotoxin)Isolated from Bacteriodes fragilis NCTC 9343

Various chemical and gas-liquid chromatographic analyses indicate that the lipid A,backbone of the lipopolysaccharide(LPS)isolated from B.fragilis NCTC 9343 is chemically con-stitutεd by a β1,6-interlinked D-glucosamine disaccharide.It is phosphorylated at its 1-positionby a glvcosidic-linkage while the ester-linked phosphate at 4'—position present generally in otherlipid A is depleted.The lipid A is lower fatty acylated in the amount of 5.2 fatty acids/lipid Amolecule(of which 0.73 forms 3-acyloxyacyl groups).The LPS containing such an incompletelipid A component has been shown endowina with a weaker endotoxicitv.     

鼠伤寒杆菌类脂A的制备及其生物学活性

类脂A(Lipid A)是细菌内毒素的重要组成成分,与O特异性链、核心多糖3者共同组成高分子的脂多糖(LPS),类脂A是其中活性成分,在脂多糖介导的各种生物学反应中起关键性作用。肠杆菌科细菌的类脂A结构基本相同。从脂多糖中提取类脂A,研究其理化特性和生物学活性有其重要意义,可     

鼠伤寒杆菌类脂A的免疫保护作用

<正> 类脂A是革兰氏阴性菌脂多糖的共同抗原成分,是决定LPS生物学活性和毒性作用的化学物质。虽然不同细菌的LPS组成各有差别,但同属或近缘菌属的类脂A都基本相同。因而,关于类脂A的免疫学特性,吸引着许多学者的关注,希望以这种共同抗原免疫机体,或者制成抗血清,用以控制人的革兰氏阴性菌感染。但是,迄今为止,各家所获的结果并不完全一致。本文用鼠伤寒杆菌的类脂A分别对小鼠和家兔进行主动和被动免疫,观察对LPS和革兰氏阴性菌感染的保护作用。