Identification of hendra virus g glycoprotein residues that are critical for receptor binding
Identification of hendra virus g glycoprotein residues that are critical for receptor binding
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DOI：
10.1128/jvi.02022-06
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发表时间：
2007-06-01
影响因子：
5.4
通讯作者：
Broder, Christopher C.
中科院分区：
文献类型：
--
作者：
Bishop, Kimberly A.;Stantchev, Tzanko S.;Broder, Christopher C.
亨德拉病毒（HeV）是一种新兴的副粘病毒，能够感染包括人类在内的多种哺乳动物并引起疾病。该病毒通过其融合（F）和附着（G）糖蛋白的协调功能来感染宿主细胞，后者负责结合病毒受体肝配蛋白B2和肝配蛋白B3。为了鉴定受体结合位点，使用丙氨酸扫描诱变策略生成了一组包含突变的 G 糖蛋白构建体。根据预测的 G 结构，目标区域中的带电氨基酸可能与已知参与其蛋白质受体相互作用的麻疹病毒 H 附着糖蛋白中的带电氨基酸同源。使用基于共沉淀的测定，HeV G 中的七个单氨基酸取代被鉴定为与 ephrinB2 和 ephrinB3 病毒受体的结合显着受损：D257A、D260A、G439A、K443A、G449A、K465A 和 D468A。当与 F 共表达时，受体相互作用的受损导致它们促进膜融合的能力随之减弱。G 糖蛋白突变体也被一组五个中的三个或更多构象依赖性单克隆抗体识别，在细胞表面表达，并保留了它们结合和共沉淀 F 的能力。有趣的是，其中一些突变 G 糖蛋白 与 F 共沉淀比野生型 G 更有效。总之，这些数据提供了强有力的生化和功能证据，表明其中一些残基可能是 HeV G 糖蛋白内构象依赖性、不连续和重叠的 ephrinB2 和 -B3 结合结构域的一部分。
Hendra virus (HeV) is an emerging paramyxovirus capable of infecting and causing disease in a variety of mammalian species, including humans. The virus infects its host cells through the coordinated functions of its fusion (F) and attachment (G) glycoproteins, the latter of which is responsible for binding the virus receptors ephrinB2 and ephrinB3. In order to identify the receptor binding site, a panel of G glycoprotein constructs containing mutations was generated using an alanine-scanning mutagenesis strategy. Based on a predicted G structure, charged amino acids residing in regions that could be homologous to those in the measles virus H attachment glycoprotein known to be involved in its protein receptor interaction were targeted. Using a coprecipitation-based assay, seven single-amino-acid substitutions in HeV G were identified as having significantly impaired binding to both the ephrinB2 and ephrinB3 viral receptors: D257A, D260A, G439A, K443A, G449A, K465A, and D468A. The impairment of receptor interaction conferred a concomitant diminution in their abilities to promote membrane fusion when coexpressed with F. The G glycoprotein mutants were also recognized by three or more conformation-dependent monoclonal antibodies of a panel of five, were expressed on the cell surface, and retained their abilities to bind and coprecipitate F. Interestingly, some of these mutant G glycoproteins coprecipitated with F more efficiently than wild-type G. Taken together, these data provide strong biochemical and functional evidence that some of these residues could be part of a conformation-dependent, discontinuous, and overlapping ephrinB2 and -B3 binding domain within the HeV G glycoprotein.