title: Enhanced assembly and colloidal stabilization of primate erythroparvovirus 1 virus-like particles for improved surface engineering.
abstract: Virus-like particles (VLPs) are the product of the self-assembly, either in vivo or in vitro, of structural components of viral capsids. These particles are excellent scaffolds for surface display of biomolecules that can be used in vaccine development and tissue-specific drug delivery. Surface engineering of VLPs requires structural stability and chemical reactivity. Herein, we report the enhanced assembly, colloidal stabilization and fluorescent labeling of primate erythroparvovirus 1 (PE1V), generally referred to as parvovirus B19. In vitro assembly of the VP2 protein of PE1V produces VLPs, which are prone to flocculate and hence undergo limited chemical modification by thiol-specific reagents like the fluorogenic monobromobimane (mBBr). We determined that the addition of 0.2M l-arginine during the assembly process produced an increased yield of soluble VLPs with good dispersion stability. Fluorescent labeling of VLPs suspended in phosphate buffered saline (PBS) added with 0.2M l-Arg was achieved in significantly shorter times than the flocculated VLPs assembled in only PBS buffer. Finally, to demonstrate the potential application of this approach, mBBr-labeled VLPs were successfully used to tag human hepatoma HepG2 cells. This new method for assembly and labeling PE1V VLPs eases its applications and provides insights on the manipulation of this biomaterial for further developments.
  
  
  CONCLUSIONS
  Application of virus-derived biomaterials sometimes requires surface modification for diverse purposes, including enhanced cell-specific interaction, the inclusion of luminescent probes for bioimaging, or the incorporation of catalytic properties for the production of enzyme nanocarriers. In this research, we reported for the first time the colloidal stabilization of the primate erythroparvovirus 1 (PE1V) virus-like particles (VLPs). Also, we report the chemical modification of the natural Cys residues located on the surface of these VLPs with a fluorescent probe, as well as its application for tagging hepatoma cells in vitro. Keeping in mind that PE1V is a human pathogen, virus-host interactions already exist in human cells, and they can be exploited for therapeutic and research aims. This study will impact on the speed in which the scientific community will be able to manipulate PE1V VLPs for diverse purposes. Additionally, this study may provide insights on the colloidal properties of these VLPs as well as in the effect of different protein additives used for protein stabilization.
authors.affiliation: Department of Chemical and Biological Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, USA; Department of Biochemistry, Faculty of Medicine, National Autonomous University of Mexico, Mexico City 04510, Mexico.
authors.forename: Sandra Paola
authors.initials: SP
authors.lastname: Sánchez-Rodríguez
authors.affiliation: Department of Biochemistry, Faculty of Medicine, National Autonomous University of Mexico, Mexico City 04510, Mexico.
authors.forename: Areli del Carmen
authors.initials: Adel C
authors.lastname: Morán-García
authors.affiliation: Department of Chemical and Biological Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, USA.
authors.forename: Olurotimi
authors.initials: O
authors.lastname: Bolonduro
authors.affiliation: Department of Chemical and Biological Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, USA; Department of Biomedical Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, USA; Department of Biology, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, USA.
authors.forename: Jonathan S
authors.initials: JS
authors.lastname: Dordick
authors.affiliation: Department of Biochemistry, Faculty of Medicine, National Autonomous University of Mexico, Mexico City 04510, Mexico. Electronic address: ismaelb@unam.mx.
authors.forename: Ismael
authors.initials: I
authors.lastname: Bustos-Jaimes
mesh_terms: D000818:Animals; D001120:Arginine / Q000494:pharmacology; D001643:Bridged Bicyclo Compounds / Q000378:metabolism; D002498:Centrifugation; D003102:Colloids / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004705:Endocytosis; D005374:Filtration; D005453:Fluorescence; D005990:Glycerol / Q000494:pharmacology; D056945:Hep G2 Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008958:Models, Molecular; D010321:Parvoviridae / Q000737:chemistry*; D011323:Primates; D015202:Protein Engineering / Q000379:methods*; D013438:Sulfhydryl Compounds / Q000378:metabolism; D013499:Surface Properties; D014764:Viral Proteins / Q000737:chemistry / Q000378:metabolism; D014771:Virion / Q000737:chemistry* / Q000187:drug effects / Q000648:ultrastructure
chemical_list: D001643:Bridged Bicyclo Compounds; D003102:Colloids; D013438:Sulfhydryl Compounds; D014764:Viral Proteins; D001120:Arginine; D005990:Glycerol; C028381:monobromobimane
keywords: Fluorescent labeling; In vitro assembly; Nanobiotechnology; Nanoparticle stabilization; Parvovirus B19; Virus-like particles