STRUCTURAL FEATURES UNIQUE TO EACH OF THE 3 ANTIGENIC SITES ON THE HEMAGGLUTININ NEURAMINIDASE PROTEIN OF NEWCASTLE-DISEASE VIRUS
STRUCTURAL FEATURES UNIQUE TO EACH OF THE 3 ANTIGENIC SITES ON THE HEMAGGLUTININ NEURAMINIDASE PROTEIN OF NEWCASTLE-DISEASE VIRUS
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DOI：
10.1016/0042-6822(88)90244-9
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发表时间：
1988-03-01
期刊：
影响因子：
3.7
通讯作者：
NAGAI, Y
中科院分区：
文献类型：
--
作者：
GOTOH, B;SAKAGUCHI, T;NAGAI, Y
用单克隆抗体对纽卡斯尔病毒（NDV）D26株血凝素-神经氨酸酶（HN）蛋白上3个不重叠的抗原位点进行筛选，并测定其HN基因序列，以确定每个位点完整性的重要氨基酸。七个变种的网站I，这是免疫显性和保守的NDV毒株，有一个变化的谷氨酸在位置347，大多是赖氨酸，并在单一的情况下，甘氨酸。在第二组的两个变体的网站IV，天冬酰胺的变化，天冬氨酸被发现在位置481。这导致与亲本病毒的天冬酰胺残基连接的寡糖被消除。连同发现位点IV通过用糖苷内切酶F处理而被破坏，这表明寡糖对于维持位点IV的结构是重要的。寡糖似乎有助于通过赋予其亲水性来暴露附近的决定簇。位点II的变体也具有非保守突变，导致在位置495处谷氨酸变为缬氨酸。通过抑制神经氨酸酶活性的抗体与一个小的底物神经氨酸乳糖识别的网站我位于更接近预测的唾液酸结合位点比其他网站识别的抗体缺乏酶抑制能力。亲本病毒HN基因的序列显示，HN蛋白的HNo前体是一个超长的蛋白质，其C端延长了45个氨基酸，与通常的HN蛋白平行测序相比。
Antigenic variants of D26 strain of Newcastle disease virus (NDV) were selected with monoclonal antibodies directed to the three nonoverlapping antigenic sites on the hemagglutinin-neuraminidase (HN) protein, and their HN genes were sequenced to identify the amino acids important for the integrity of each site. Seven variants for site I, which is immunodominant and conserved among NDV strains, had a change of glutamic acid at position 347, mostly to lysine, and in a single case, to glycine. In the second group of two variants for site IV, a change of asparagine to aspartic acid was found at position 481. This resulted in elimination of the oligosaccharide attached to this asparagine residue of the parental virus. Together with the finding that the site IV was destroyed by treatment with endoglycosidase F, it was suggested that the oligosaccharide is important for maintaining the structure of site IV. The oligosaccharide appeared to contribute to exposing a nearby determinant by conferring hydrophilicity on it. A variant for site II had also a nonconservative mutation resulting in the change of glutamic acid to valine at position 495. The site I recognized by antibodies which inhibit neuraminidase activity with a small substrate neuraminlactose was located closer to the predicted sialic acid-binding site than to the other sites recognized by antibodies lacking the enzyme-inhibiting capacity. The sequence of the parental virus HN gene revealed that the HNo precursor for the HN protein is an extra-long protein whose C terminus is elongated by 45 amino acids, compared with the usual HN protein sequenced in parallel.