IMMUNOCHEMICAL SPECIFICITY OF THE COMBINING SITE OF WISTARIA-FLORIBUNDA HEMAGGLUTININ
IMMUNOCHEMICAL SPECIFICITY OF THE COMBINING SITE OF WISTARIA-FLORIBUNDA HEMAGGLUTININ
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DOI：
10.1021/bi00547a024
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发表时间：
1980-01-01
期刊：
影响因子：
2.9
通讯作者：
KABAT, EA
中科院分区：
文献类型：
--
作者：
SUGII, S;KABAT, EA
用免疫化学定量沉淀法和沉淀素抑制法研究了不溶性聚亮氨酸猪胃粘蛋白A+H(PL-HOG A+H)物质吸附、乳糖洗脱、Sephadex G-200凝胶过滤等步骤纯化的华支睾吸虫血凝素的特异性。纯化的血凝素分子量为68,000，等电点为5.0，均一的电泳性和免疫化学性质，由两个共价连接的分子量32,000亚基组成。A型、BI型、Lea血型和前体I型物质沉淀，B血型物质轻度酸解(P1)沉淀，B、H型血型物质沉淀较差。去唾液酸类粘液(ASOR)也能使其沉淀，而无乳糖粘液(AGOR)和失活的抗冻糖蛋白不能沉淀。对各种单糖、糖苷和寡糖的抑制试验表明，血凝素对末端非还原α连接的DGalNAc最具特异性。抑制效果最好的是双糖DGalNAc.α。(1.fwdarw.6)DGAL，是DGalNAc的8.8倍。A活性的二、三和五糖的效力分别是DGalNAc.Alpha的3.3、3.8和12.0倍。(1.fwdarw.6)DGAL。在所测试的DGalNAc的糖苷中，pNph.beta.DGalNAc是最有效的。它的活性是DGalNAc的6.0倍，但比DGalNAc低1.5倍。(1.fwdarw.6)DGAL。尽管最好的抑制剂是α-连接的二糖DGalNAc.α。(1.fwdarw.6)DGAL和Me.Alpha.DGalNAc优于Me.beta.DGalNAc，pNph.beta.DGalNAc强于pNph.alpha.DGalNAc。分子模型显示pNph.beta.DGalNAc和DGalNAc.Alpha。(1.fwdarw.6)DGAL在形状上类似而不同于pNph.alpha.DGalNAc。因此，血凝素的结合部位至少与二糖一样大，疏水相互作用和形状对结合很重要。
The specificity of W. floribunda hemagglutinin, purified by adsorption on insoluble polyleucyl hog gastric mucin blood group A + H (PL-hog A + H) substance, elution with lactose and gel filtration on Sephadex G-200, was studied immunochemically by quantitative precipitin and precipitin inhibition assays. The purified hemagglutinin, with a WM of 68,000 and an isoelectric point of 5.0, was homogeneous electrophoretically and immunochemically and was made up to 2 covalently linked subunits of MW 32,000. It was precipitated by blood group A, BI, Lea and precursor I substances and by B substance subjected to mild acid hydrolysis (P1) but poorly by blood groups B and H substances. It was also precipitated by asialoorosomucoid (ASOR) but not by agalactoorosomucoid (AGOR) and inactive antifreeze glycoprotein. Inhibition assays with various monosaccharides, glycosides and oligosaccharides indicate that the hemagglutinin is most specific for terminal nonreducing .alpha.-linked DGalNAc. The best inhibitor was the disaccharide DGalNAc.alpha. (1 .fwdarw. 6)DGal which was 8.8 times more potent than DGalNAc. The A-active di-, tri-, and pentasaccharides were 3.3, 3.8 and 12.0 times less potent than DGalNAc.alpha. (1 .fwdarw. 6)DGal, respectively. Among the glycosides of DGalNAc tested, pNph.beta.DGalNAc was most potent. It was 6.0 times more active than DGalNAc but 1.5 times less active than DGalNAc.alpha. (1 .fwdarw. 6)DGal. Although the best inhibitor was the .alpha.-linked disaccharide DGalNAc.alpha. (1 .fwdarw. 6)DGal and Me.alpha.DGalNAc was better than Me.beta.DGalNAc, pNph.beta.DGalNAc was more potent than pNph.alpha.DGalNAc. Molecular models showed pNph.beta.DGalNAc and DGalNAc.alpha. (1 .fwdarw. 6)DGal to be similar in shape and to differ from pNph.alpha.DGalNAc. Thus the combining site of the hemagglutinin is at least as large as a disaccharide and hydrophobic interaction and shape are important for binding.