title: Mutant plant viruses with cell binding motifs provide differential adhesion strengths and morphologies.
abstract: The ability of  Tobacco mosaic  virus (TMV) to tolerate various amino acid insertions near its carboxy terminus is well-known. Typically these inserts are based on antigenic sequences for vaccine development with plant viruses as carriers. However, we determined that the structural symmetries and the size range of the viruses could also be modeled to mimic the extracellular matrix proteins by inserting cell-binding sequences to the virus coat protein. The extracellular matrix proteins play important roles in guiding cell adhesion, migration, proliferation, and stem cell differentiation. Previous studies with TMV demonstrated that the native and phosphate-modified virus particles enhanced stem cell differentiation toward bone-like tissues. Based on these studies, we sought to design and screen multiple genetically modified TMV mutants with reported cell adhesion sequences to expand the virus-based tools for cell studies. Here, we report the design of these mutants with cell binding amino acid motifs derived from several proteins, the stabilities of the mutants against proteases during purification and storage, and a simple and rapid functional assay to quantitatively determine adhesion strengths by centrifugal adhesion assay. Among the mutants, we found that cells on TMV expressing RGD motifs formed filopodial extensions with weaker attachment profiles, whereas the cells on TMV expressing collagen I mimetic sequence displayed little spreading but higher attachment strengths.
authors.affiliation: Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, South Carolina 29208, United States.
authors.forename: L Andrew
authors.initials: LA
authors.lastname: Lee
authors.forename: Quyen L
authors.initials: QL
authors.lastname: Nguyen
authors.forename: Laying
authors.initials: L
authors.lastname: Wu
authors.forename: Gary
authors.initials: G
authors.lastname: Horvath
authors.forename: Richard S
authors.initials: RS
authors.lastname: Nelson
authors.forename: Qian
authors.initials: Q
authors.lastname: Wang
mesh_terms: D020816:Amino Acid Motifs; D000818:Animals; D040761:Biomimetic Materials / Q000737:chemistry*; D016466:CHO Cells; D002213:Capsid / Q000737:chemistry; D002448:Cell Adhesion; D003094:Collagen / Q000737:chemistry; D006224:Cricetinae; D016326:Extracellular Matrix Proteins / Q000737:chemistry / Q000235:genetics; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D009154:Mutation; D012367:RNA, Viral / Q000737:chemistry / Q000235:genetics*; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics; D023822:Tissue Engineering / Q000379:methods*; D014027:Tobacco Mosaic Virus / Q000737:chemistry / Q000235:genetics*; D014759:Viral Envelope Proteins / Q000737:chemistry / Q000235:genetics*; D014771:Virion / Q000235:genetics
chemical_list: D016326:Extracellular Matrix Proteins; D012367:RNA, Viral; D011994:Recombinant Proteins; D014759:Viral Envelope Proteins; D003094:Collagen