Glycine Substitution at Helix-to-Coil Transitions Facilitates the Structural Determination of a Stabilized Subtype C HIV Envelope Glycoprotein.
Glycine Substitution at Helix-to-Coil Transitions Facilitates the Structural Determination of a Stabilized Subtype C HIV Envelope Glycoprotein.
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DOI：
10.1016/j.immuni.2017.04.014
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发表时间：
2017-05-16
期刊：
影响因子：
32.4
通讯作者：
Wyatt RT
中科院分区：
文献类型：
--
作者：
Guenaga J;Garces F;de Val N;Stanfield RL;Dubrovskaya V;Higgins B;Carrette B;Ward AB;Wilson IA;Wyatt RT
HIV-1包膜糖蛋白（Env）设计的进展产生了天然样三聚体和高分辨率进化枝A、B和G结构，并引发中和抗体。然而，高分辨率的进化枝C结构是至关重要的，因为这种亚型占全球艾滋病毒感染的大多数，但由于其不稳定性，有序的进化枝C Env三聚体的生产更具挑战性。基于Env融合机制中的靶向甘氨酸取代，我们定义了一种不利于导致融合后构象的螺旋转变的一般方法，从而有利于融合前状态。我们产生了稳定的可溶性进化枝C Env（16055 NFL），并在3.9 nm下测定了其晶体结构。其总体构象与SOSIP.664和天然Env三聚体相似，但包括gp 120和gp 41之间的共价接头、工程化的201-433二硫键以及对应于22个N-聚糖的密度。Env结构指导的设计策略产生了多个同质的交叉进化枝免疫原，具有推进HIV疫苗开发的潜力。交叉进化枝Env比较揭示了总体结构和N-聚糖的保守性NFL结构揭示了稳定的TD接触和201 C-A433 C二硫键CC NFL Env重新设计允许产生来自进化枝A、B和C的免疫原。Guenaga等人描述了稳定的C亚型天然柔性连接（NFL）Env的3.9 kDa晶体结构和允许从不同HIV毒株产生Env免疫原的多结构指导设计策略。
Advances in HIV-1 envelope glycoprotein (Env) design generate native-like trimers and high-resolution clade A, B, and G structures and elicit neutralizing antibodies. However, a high-resolution clade C structure is critical, as this subtype accounts for the majority of HIV infections worldwide, but well-ordered clade C Env trimers are more challenging to produce due to their instability. Based on targeted glycine substitutions in the Env fusion machinery, we defined a general approach that disfavors helical transitions leading to post-fusion conformations, thereby favoring the pre-fusion state. We generated a stabilized, soluble clade C Env (16055 NFL) and determined its crystal structure at 3.9 Å. Its overall conformation is similar to SOSIP.664 and native Env trimers but includes a covalent linker between gp120 and gp41, an engineered 201-433 disulfide bond, and density corresponding to 22 N-glycans. Env-structure-guided design strategies resulted in multiple homogeneous cross-clade immunogens with the potential to advance HIV vaccine development. Structure-guided design generates an HIV clade C Env crystal structure at 3.9 Å Cross-clade Env comparison discloses overall structural and N-glycan conservation The NFL structure reveals stabilizing TD contacts and the 201C-A433C disulfide CC NFL Env redesign permits the generation of immunogens derived from clades A, B, and C The majority of HIV-1 infections worldwide emanate from subtype C strains. Guenaga et al. describe the 3.9 Å crystal structure of a stabilized subtype C native, flexibly linked (NFL) Env and multiple structure-guided design strategies that permit the generation of Env immunogens from diverse HIV strains.