The carbohydrate epitope of the neutralizing anti-HIV-1 antibody 2G12.
The carbohydrate epitope of the neutralizing anti-HIV-1 antibody 2G12.
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中和抗 HIV-1 抗体 2G12 的碳水化合物表位。
DOI：
10.1007/978-1-4615-0065-0_13
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发表时间：
2003
影响因子：
--
通讯作者：
Rudd,PaulineM
中科院分区：
文献类型：
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作者：
Scanlan,ChristopherN;Pantophlet,Ralph;Wormald,MarkR;Saphire,EricaOllmann;Calarese,Daniel;Stanfield,Robyn;Wilson,IanA;Katinger,Hermann;Dwek,RaymondA;Burton,DennisR;Rudd,PaulineM
2G12是一种广泛中和的抗人类免疫缺陷病毒1型（HIV-1）的人单克隆抗体，先前已被证明与gp120上的碳水化合物依赖性表位结合。在这里，使用定点诱变和碳水化合物分析来进一步确定2G12表位。丙氨酸扫描诱变表明，通过N→A取代去除与N295、N332、N339、N386和N392残基相关的N-链碳水化合物附着序列可显著降低2G12与gp120JR.CSF的结合亲和力。诱变研究没有提供令人信服的证据证明gp120氨基酸侧链参与了2G12的结合。当gp120被猪曲霉甘露糖苷酶、杰克豆甘露糖苷酶或内糖苷酶H处理时，抗体结合被抑制，这表明gp120上低聚甘露糖聚糖的Manal→2man连接糖是2G12结合所必需的。与此发现一致的是，单甘露糖可以抑制2G12与gp120的结合，而其他己糖则不能。本文提供的数据表明，2G12最可能的表位是由gp120外表面的特定甘露糖残基簇形成的，其他聚糖在维持表位构象中起间接作用。[病毒学杂志，2002年7月，第7306-7321页，第76卷，第14期。]
2G12 is a broadly neutralizing human monoclonal antibody against human immunodeficiency virus type-1 (HIV-1) that has previously been shown to bind to a carbohydrate-dependent epitope on gp120. Here, site-directed mutagenesis and carbohydrate analysis were used to define further the 2G12 epitope. Alanine scanning mutagenesis showed that elimination of the N-linked carbohydrate attachment sequences associated with residues N295, N332, N339, N386, and N392 by N → A substitution produced significant decreases in 2G12 binding affinity to gp120JR.CSF. The mutagenesis studies provided no convincing evidence for the involvement of gp120 amino acid side chains in 2G12 binding. Antibody binding was inhibited when gp120 was treated withAspergillus saitoimannosidase, Jack Bean mannosidase, or endoglycosidase H, indicating that Manal → 2Man-linked sugars of oligomannose glycans on gp120 are required for 2G12 binding. Consistent with this finding, the binding of 2G12 to gp120 could be inhibited by monomeric mannose but not by other hexoses. The data presented here suggests that the most likely epitope for 2G12 is formed from a specific cluster of mannose residues on the outer face of gp120, with the other glycans playing an indirect role in maintaining epitope conformation. [Journal of Virology, July 2002, pp. 7306–7321, Vol. 76, No. 14.]