Deficiency in beta 1,3-galactosyltransferase of a Leishmania major lipophosphoglycan mutant adversely influences the Leishmania sand fly interaction
Deficiency in beta 1,3-galactosyltransferase of a Leishmania major lipophosphoglycan mutant adversely influences the Leishmania sand fly interaction
复制标题
DOI：
10.1074/jbc.271.34.20573
复制
发表时间：
1996-08-23
影响因子：
4.8
通讯作者：
Sacks, DL
中科院分区：
文献类型：
--
作者：
Butcher, BA;Turco, SJ;Sacks, DL
为了研究细胞表面脂磷脂多糖(LPG)的侧链寡糖的功能，用识别L含半乳糖侧链的单抗WIC79，3凝集突变的主要侧链生物合成缺陷利什曼原虫，生化特征表明，该突变株缺乏与天然主要载体白头翁中肠显著结合的能力，也不能在消化的血粉后在沙蝇体内维持感染。生化特征表明，Spock LPG在结构上与无法结合和维持感染的唐氏利什曼原虫的LPG相似Popatasi中肠与缺乏半乳糖末端低聚糖侧链的表面LPG的表达密切相关，利用野生型或Spock膜的体外半乳糖转移酶分析确定Spock LPG生物合成的缺陷是由于β1，3-半乳糖基转移酶活性的缺陷，而不是LPG的修饰，这将阻止其作为半乳糖加成的胜任底物。这些实验结果表明，SPECK缺乏用于侧链添加的β1，3-半乳糖基转移酶，而LPG侧链是主要与P，Papatasi的L结合并产生转染性感染所必需的。
To study the function of side chain oligosaccharides of the cell-surface lipophosphoglycan (LPG), mutagenized Leishmania major defective in side chain biosynthesis were negatively selected by agglutination with the monoclonal antibody WIC79,3, which recognizes the galactose-containing side chains of L, major LPG, One such mutant, called Spock, lacked the ability to bind significantly to midguts of the natural L. major vector, Phlebotomus papatasi, and to maintain infection in the sand fly after excretion of the digested bloodmeal, Biochemical characterization of Spock LPG revealed its structural similarity to the LPG of Leishmania donovani, a species whose inability to bind to and maintain infections in P, papatasi midguts has been strongly correlated with the expression of a surface LPG lacking galactose-terminated oligosaccharide side chains, An in vitro galactosyltransferase assay using wild-type or Spock membranes was used to determine that the defect in Spock LPG biosynthesis is a result of defective beta 1,3-galactosyltransferase activity as opposed to a modification of LPG, which would prevent it from serving as a competent substrate for galactose addition, The results of these experiments show that Speck lacks the beta 1,3-galactosyltransferase for side chain addition and that the LPG side chains are required for L, major to bind to and to produce transmissible infection in P, papatasi.