title: Analysis of the dynamics of assembly and structural impact for a histidine tagged FGF1-1.5 nm Au nanoparticle bioconjugate.
abstract: Whether assembling proteins onto nanoscale, mesoscopic, or macroscropic material surfaces, maintaining a protein's structure and function when conjugated to a surface is complicated by the high propensity for electrostatic or hydrophobic surface interactions and the possibility of direct metal coordination of protein functional groups. In this study, the assembly of a 1.5 nm CAAKA passivated gold nanoparticle (AuNP) onto FGF1 (human acidic fibroblast growth factor) using an amino terminal His(6) tag is analyzed. The impact of structure and time-dependent changes in the structural elements in FGF1and FGF1-heparin in the presence of the AuNP is probed by a molecular beacon fluorescence assay, circular dichroism, and NMR spectroscopy. Analysis of the results indicates that a time-dependent evolution of the protein structure without loss of FGF1 heparin binding occurs following the formation of the initial FGF1-AuNP complex. The time-dependent changes are believed to reflect protein sampling of the AuNP surface to minimize the free energy of the AuNP-FGF1 complex without impacting FGF1 function.
authors.affiliation: Department of Chemistry and Biochemistry and Kasha Laboratory Institute of Molecular Biophysics, Florida State University, Tallahassee, Florida 32306, USA.
authors.forename: Joshua M
authors.initials: JM
authors.lastname: Kogot
authors.forename: Alex M
authors.initials: AM
authors.lastname: Parker
authors.forename: Jihun
authors.initials: J
authors.lastname: Lee
authors.forename: Michael
authors.initials: M
authors.lastname: Blaber
authors.forename: Geoffrey F
authors.initials: GF
authors.lastname: Strouse
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Logan
mesh_terms: D000345:Affinity Labels / Q000737:chemistry*; D016220:Fibroblast Growth Factor 1 / Q000737:chemistry*; D006046:Gold; D006493:Heparin; D006639:Histidine / Q000737:chemistry*; D006801:Humans; D056004:Molecular Dynamics Simulation; D053758:Nanoparticles / Q000737:chemistry*; D009842:Oligopeptides / Q000737:chemistry*; D011485:Protein Binding; D013057:Spectrum Analysis; D013499:Surface Properties
chemical_list: D000345:Affinity Labels; C471213:His-His-His-His-His-His; D009842:Oligopeptides; D016220:Fibroblast Growth Factor 1; D006639:Histidine; D006046:Gold; D006493:Heparin