title: Structural analysis and insertion study reveal the ideal sites for surface displaying foreign peptides on a betanodavirus-like particle.
abstract: Betanodavirus infection causes fatal disease of viral nervous necrosis in many cultured marine and freshwater fish worldwide and the virus-like particles (VLP) are effective vaccines against betanodavirus. But vaccine and viral vector designs of betanodavirus VLP based on their structures remain lacking. Here, the three-dimensional structure of orange-spotted grouper nervous necrosis virus (OGNNV) VLP (RBS) at 3.9 Å reveals the organization of capsid proteins (CP). Based on the structural results, seven putative important sites were selected to genetically insert a 6× histidine (His)-tag for VLP formation screen, resulting in four His-tagged VLP (HV) at positions N-terminus, Ala220, Pro292 and C-terminus. The His-tags of N-terminal HV (NHV) were concealed inside virions while those of 220HV and C-terminal HV (CHV) were displayed at the outer surface. NHV, 220HV and CHV maintained the same cell entry ability as RBS in the Asian sea bass (SB) cell line, indicating that their similar surface structures can be recognized by the cellular entry receptor(s). For application of vaccine design, chromatography-purified CHV could provoke NNV-specific antibody responses as strong as those of RBS in a sea bass immunization assay. Furthermore, in carrying capacity assays, N-terminus and Ala220 can only carry short peptides and C-terminus can even accommodate large protein such as GFP to generate fluorescent VLP (CGV). For application of a viral vector, CGV could be real-time visualized to enter SB cells in invasion study. All the results confirmed that the C-terminus of CP is a suitable site to accommodate foreign peptides for vaccine design and viral vector development.
authors.affiliation: State Key Laboratory of Biocontrol, MOE Key Laboratory of Aquatic Product Safety, Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China. xiejf@mail.sysu.edu.cn.
authors.forename: Junfeng
authors.initials: J
authors.lastname: Xie
authors.affiliation: State Key Laboratory of Biocontrol, MOE Key Laboratory of Aquatic Product Safety, Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China. leekp@qq.com.
authors.forename: Kunpeng
authors.initials: K
authors.lastname: Li
authors.affiliation: State Key Laboratory of Biocontrol, MOE Key Laboratory of Aquatic Product Safety, Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China. 710620731@qq.com.
authors.forename: Yuanzhu
authors.initials: Y
authors.lastname: Gao
authors.affiliation: State Key Laboratory of Biocontrol, MOE Key Laboratory of Aquatic Product Safety, Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China. 997572592@qq.com.
authors.forename: Runqing
authors.initials: R
authors.lastname: Huang
authors.affiliation: Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 518080, China. 247254612@qq.com.
authors.forename: Yuxiong
authors.initials: Y
authors.lastname: Lai
authors.affiliation: State Key Laboratory of Biocontrol, MOE Key Laboratory of Aquatic Product Safety, Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China. 824993409@qq.com.
authors.forename: Yan
authors.initials: Y
authors.lastname: Shi
authors.affiliation: State Key Laboratory of Biocontrol, MOE Key Laboratory of Aquatic Product Safety, Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China. 761061605@qq.com.
authors.forename: Shaowei
authors.initials: S
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Biocontrol, MOE Key Laboratory of Aquatic Product Safety, Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China. 1576660207@qq.com.
authors.forename: Guohua
authors.initials: G
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Biocontrol, MOE Key Laboratory of Aquatic Product Safety, Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China. lsszqf@mail.sysu.edu.cn.
authors.forename: Qinfen
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Biocontrol, MOE Key Laboratory of Aquatic Product Safety, Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China. lsshjg@mail.sysu.edu.cn.|School of Marine Sciences, Sun Yat-sen University, Guangzhou, 510275, China. lsshjg@mail.sysu.edu.cn.
authors.forename: Jianguo
authors.initials: J
authors.lastname: He
mesh_terms: D000818:Animals; D001492:Bass; D036022:Capsid Proteins / Q000235:genetics / Q000378:metabolism*; D005393:Fish Diseases / Q000517:prevention & control* / Q000821:virology; D015967:Gene Expression Regulation, Viral; D008958:Models, Molecular; D016254:Mutagenesis, Insertional; D030381:Nodaviridae / Q000235:genetics / Q000378:metabolism*; D010455:Peptides / Q000276:immunology / Q000378:metabolism*; D011487:Protein Conformation; D012327:RNA Virus Infections / Q000517:prevention & control / Q000662:veterinary* / Q000821:virology; D014765:Viral Vaccines / Q000276:immunology*; D053586:Virus Internalization
chemical_list: D036022:Capsid Proteins; D010455:Peptides; D014765:Viral Vaccines