title: VP1 residues around the five-fold axis of enterovirus A71 mediate heparan sulfate interaction.
abstract: Enterovirus A71 (EV-A71) is a neurotropic enterovirus that uses heparan sulfate as an attachment receptor. The molecular determinants of EV-A71-heparan sulfate interaction are unknown. With In silico heparin docking and mutagenesis of all possible lysine residues in VP1, we identified that K162, K242 and K244 are responsible for heparin interaction and inhibition. EV-A71 mutants with K242A and K244A rapidly acquired compensatory mutations, T100K or E98A, and Q145R-T237N respectively, which restored the heparin-binding phenotype. Both VP1-98 and VP1-145 modulates heparin binding. Heparin-binding phenotype was completely abolished with VP1-E98-E145, but was restored by an E98K or E145Q substitution. During cell culture adaptation, EV-A71 rapidly acquired K98 or Q/G145 to restore the heparin-binding phenotype. Together with next-generation sequencing analysis, our results implied that EV-A71 has high genetic plasticity by modulating positively-charged residues at the five-fold axis during in vitro heparin adaptation. Our finding has impact on EV-A71 vaccine production, evolutionary studies and pathogenesis.
authors.affiliation: Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Chee Wah
authors.initials: CW
authors.lastname: Tan
authors.affiliation: Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: I-Ching
authors.initials: IC
authors.lastname: Sam
authors.affiliation: Department of Chemistry, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia; Computational Simulation Modelling Laboratory (CSML), Department of Chemistry and Center of Excellence for Innovation in Chemistry and Materials Science Research Center, Faculty of Science, Chiang Mai University, Thailand.
authors.forename: Vannajan Sanghiran
authors.initials: VS
authors.lastname: Lee
authors.affiliation: Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Hui Vern
authors.initials: HV
authors.lastname: Wong
authors.affiliation: Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia. Electronic address: chanyf@um.edu.my.
authors.forename: Yoke Fun
authors.initials: YF
authors.lastname: Chan
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D029821:Enterovirus A, Human / Q000235:genetics / Q000378:metabolism*; D004769:Enterovirus Infections / Q000378:metabolism* / Q000821:virology; D006497:Heparan Sulfate / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D011485:Protein Binding; D011991:Receptors, Virus / Q000378:metabolism*; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D006497:Heparan Sulfate; D011991:Receptors, Virus; D014764:Viral Proteins
keywords: Enterovirus A71; Five-fold axis; Hand, foot and mouth disease; Heparan sulfate