Studies of the binding properties of influenza hemagglutinin receptor-site mutants
Studies of the binding properties of influenza hemagglutinin receptor-site mutants
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DOI：
10.1006/viro.1997.8958
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发表时间：
1998-02-01
期刊：
影响因子：
3.7
通讯作者：
Steinhauer, DA
中科院分区：
文献类型：
--
作者：
Martín, J;Wharton, SA;Steinhauer, DA
在流感血凝素（HA）受体结合位点进行了位点特异性突变，以评估单个氨基酸残基对受体识别的贡献。筛选用重组牛痘病毒感染的细胞表达的突变HA结合人红细胞的能力，表明涉及保守残基Y 98 F，H183 F，和L194 A严重限制结合，并且取代W153 A阻止HA的细胞表面表达。唾液酸的OH似乎略微增加红细胞结合，取代G225 R也是如此。直接或间接参与受体结合的其他残基S136 T、S136 A、Y195 F、G225 D和L226 P的取代对这两个极端之间的结合具有中等影响。根据非免疫马血清对红细胞结合的抑制作用，对受体结合特异性变化的估计表明，突变体G225 R和L226 P与野生型HA不同，未受到抑制; Y195 F和G225 D突变体与野生型一样，受到抑制;突变体S136 A、S136 T、E190 A和S228 G的红细胞结合仅受到部分抑制。还通过转染构建了包含突变HA Y 98 F、S136 T、G225 D和S228 G的病毒，所述突变HA覆盖了所观察到的红细胞结合性质的范围。所有四种转染病毒在MDCK细胞和鸡胚中的复制与野生型X-31病毒一样有效，尽管Y 98 F突变病毒不能凝集红细胞。细胞表面唾液酸水平降低的突变MDCK细胞易受S136 T、G225 D和S228 G转染病毒和野生型感染，但不受Y 98 F转染病毒感染。(C)北京：科学出版社.
Site-specific mutations have been made in the influenza hemagglutinin (HA) receptor binding site to assess the contribution of individual amino acid residues to receptor recognition. Screening of mutant HAs, expressed using recombinant vaccinia virus-infected cells, for their abilities to bind human erythrocytes indicated that substitutions involving conserved residues Y98F, H183F, and L194A severely restricted binding and that the substitution W153A prevented cell surface expression of HA Mutation of residues E190 and S228 that are in positions to form hydrogen bonds with the 9-OH of sialic acid appeared to increase erythrocyte binding slightly, as did the substitution G225R. Substitutions of other residues that are directly or indirectly involved in receptor binding, S136T, S136A, Y195F, G225D, and L226P, had intermediate effects on binding between these two extremes. Estimates of changes in receptor binding specificity based on inhibition of binding to erythrocytes by nonimmune horse sera indicated that mutants G225R and L226P, unlike wild-type HA, were not inhibited; Y195F and G225D mutants were, like wild type, inhibited; and erythrocyte binding by mutants S136A, S136T, E190A, and S228G was only partially inhibited. Viruses containing mutant HAs Y98F, S136T, G225D, and S228G that cover the range of erythrocyte binding properties observed were also constructed by transfection. Ail four transfectant Viruses replicated in MDCK cells and embryonated hens' eggs as efficiently as wild-type X-31 virus, although the Y98F mutant virus was unable to agglutinate erythrocytes. Mutant MDCK cells that have reduced levels of cell surface sialic acids were susceptible to infection by S136T, G225D, and S228G transfectant viruses and by wild type but not by the Y98F transfectant virus. (C) 1998 Academic Press.