Wang Jiaqi
Email Address
gmswaji@nus.edu.sg
4 results
Publication Search Results
Now showing 1 - 4 of 4
Publication Molecular basis of dengue virus serotype 2 morphological switch from 29°C to 37°C(Public Library of Science, 2019) Lim, X.-N.; Shan, C.; Marzinek, J.K.; Dong, H.; Ng, T.S.; Ooi, J.S.G.; Fibriansah, G.; Wang, J.; Verma, C.S.; Bond, P.J.; Shi, P.-Y.; Lok, S.-M.; DEAN'S OFFICE (DUKE-NUS MEDICAL SCHOOL); BIOLOGICAL SCIENCES; DUKE-NUS MEDICAL SCHOOLThe ability of DENV2 to display different morphologies (hence different antigenic properties) complicates vaccine and therapeutics development. Previous studies showed most strains of laboratory adapted DENV2 particles changed from smooth to "bumpy" surfaced morphology when the temperature is switched from 29°C at 37°C. Here we identified five envelope (E) protein residues different between two alternative passage history DENV2 NGC strains exhibiting smooth or bumpy surface morphologies. Several mutations performed on the smooth DENV2 infectious clone destabilized the surface, as observed by cryoEM. Molecular dynamics simulations demonstrated how chemically subtle substitution at various positions destabilized dimeric interactions between E proteins. In contrast, three out of four DENV2 clinical isolates showed a smooth surface morphology at 37°C, and only at high fever temperature (40°C) did they become "bumpy". These results imply vaccines should contain particles representing both morphologies. For prophylactic and therapeutic treatments, this study also informs on which types of antibodies should be used at different stages of an infection, i.e., those that bind to monomeric E proteins on the bumpy surface or across multiple E proteins on the smooth surfaced virus. Copyright © 2019 Lim et al.Publication A potent anti-dengue human antibody preferentially recognizes the conformation of E protein monomers assembled on the virus surface(2014) Fibriansah G.; Tan J.L.; Smith S.A.; de Alwis A.R.; Ng T.-S.; Kostyuchenko V.A.; Ibarra K.D.; Wang J.; Harris E.; de Silva A.; Crowe J.E.; Lok S.-M.; DUKE-NUS MEDICAL SCHOOLDengue virus (DENV), which consists of four serotypes (DENV1-4), infects over 400 million people annually. Previous studies have indicated most human monoclonal antibodies (HMAbs) from dengue patients are cross-reactive and poorly neutralizing. Rare neutralizing HMAbs are usually serotype-specific and bind to quaternary structure-dependent epitopes. We determined the structure of DENV1 complexed with Fab fragments of a highly potent HMAb 1F4 to 6 Å resolution by cryo-EM. Although HMAb 1F4 appeared to bind to virus and not E proteins in ELISAs in the previous study, our structure showed that the epitope is located within an envelope (E) protein monomer, and not across neighboring E proteins. The Fab molecules bind to domain I (DI), and DI-DII hinge of the E protein. We also showed that HMAb 1F4 can neutralize DENV at different stages of viral entry in a cell type and receptor dependent manner. The structure reveals the mechanism by which this potent and specific antibody blocks viral infection. © 2014 The Authors.Publication High flavivirus structural plasticity demonstrated by a non-spherical morphological variant(Nature Research, 2020-06-19) Morrone, S.R.; Chew, V.S.Y.; Lim, X.-N.; Ng, T.-S.; Kostyuchenko, V.A.; Zhang, S.; Chew, P.-L.; Lee, J.; Tan, J.L.; Wang, J.; Tan, T.Y.; Shi, J.; Screaton, G.; Morais, M.C.; Lok, S.-M.; MICROBIOLOGY AND IMMUNOLOGY; BIOLOGICAL SCIENCES; DUKE-NUS MEDICAL SCHOOLPrevious flavivirus (dengue and Zika viruses) studies showed largely spherical particles either with smooth or bumpy surfaces. Here, we demonstrate flavivirus particles have high structural plasticity by the induction of a non-spherical morphology at elevated temperatures: the club-shaped particle (clubSP), which contains a cylindrical tail and a disc-like head. Complex formation of DENV and ZIKV with Fab C10 stabilize the viruses allowing cryoEM structural determination to ~10 Å resolution. The caterpillar-shaped (catSP) Fab C10:ZIKV complex shows Fabs locking the E protein raft structure containing three E dimers. However, compared to the original spherical structure, the rafts have rotated relative to each other. The helical tail structure of Fab C10:DENV3 clubSP showed although the Fab locked an E protein dimer, the dimers have shifted laterally. Morphological diversity, including clubSP and the previously identified bumpy and smooth-surfaced spherical particles, may help flavivirus survival and immune evasion. © 2020, The Author(s).Publication Capsid protein structure in Zika virus reveals the flavivirus assembly process(Nature Research, 2020) Tan, T.Y.; Fibriansah, G.; Kostyuchenko, V.A.; Ng, T.-S.; Lim, X.-X.; Zhang, S.; Lim, X.-N.; Wang, J.; Shi, J.; Morais, M.C.; Corti, D.; Lok, S.-M.; MICROBIOLOGY AND IMMUNOLOGY; DEAN'S OFFICE (DUKE-NUS MEDICAL SCHOOL); BIOLOGICAL SCIENCES; DUKE-NUS MEDICAL SCHOOLStructures of flavivirus (dengue virus and Zika virus) particles are known to near-atomic resolution and show detailed structure and arrangement of their surface proteins (E and prM in immature virus or M in mature virus). By contrast, the arrangement of the capsid proteins:RNA complex, which forms the core of the particle, is poorly understood, likely due to inherent dynamics. Here, we stabilize immature Zika virus via an antibody that binds across the E and prM proteins, resulting in a subnanometer resolution structure of capsid proteins within the virus particle. Fitting of the capsid protein into densities shows the presence of a helix previously thought to be removed via proteolysis. This structure illuminates capsid protein quaternary organization, including its orientation relative to the lipid membrane and the genomic RNA, and its interactions with the transmembrane regions of the surface proteins. Results show the capsid protein plays a central role in the flavivirus assembly process. © 2020, The Author(s).