title: Physicochemical characteristics of protein-NP bioconjugates: the role of particle curvature and solution conditions on human serum albumin conformation and fibrillogenesis inhibition.
abstract: Gold nanoparticles (Au NPs) from 5 to 100 nm in size synthesized with HAuCl(4) and sodium citrate were complexed with the plasma protein human serum albumin (HSA). Size, surface charge, and surface plasmon bands of the Au NPs are largely modified by the formation of a protein corona via electrostatic interactions and hydrogen bonding as revealed by thermodynamic data. Negative values of the entropy of binding suggested a restriction in the biomolecule mobility upon adsorption. The structure of the adsorbed protein molecules is slightly affected by the interaction with the metal surface, but this effect is enhanced as the NP curvature decreases. Also, it is observed that the protein molecules adsorbed onto the NP surface are more resistant to complete thermal denaturation than free protein ones as deduced from the increases in the melting temperature of the adsorbed protein. Differences in the conformations of the adsorbed protein molecules onto small (<40 nm) and large NPs were observed on the basis of ζ-potential data and FTIR spectroscopy, also suggesting a better resistance of adsorbed protein molecules to thermal denaturing conditions. We think this enhanced protein stability is responsible for a reduced formation of HSA amyloid-like fibrils in the presence of small Au NPs under HSA fibrillation conditions.
authors.affiliation: Grupo de Física de Coloides y Polímeros, Departamento de Física de la Materia Condensada, Facultad de Física, Campus Vida, 15782, Universidad de Santiago de Compostela, Spain.
authors.forename: Sonia
authors.initials: S
authors.lastname: Goy-López
authors.forename: Josué
authors.initials: J
authors.lastname: Juárez
authors.forename: Manuel
authors.initials: M
authors.lastname: Alatorre-Meda
authors.forename: Eudald
authors.initials: E
authors.lastname: Casals
authors.forename: Victor F
authors.initials: VF
authors.lastname: Puntes
authors.forename: Pablo
authors.initials: P
authors.lastname: Taboada
authors.forename: Victor
authors.initials: V
authors.lastname: Mosquera
mesh_terms: D002627:Chemistry, Physical; D006046:Gold / Q000737:chemistry* / Q000494:pharmacology*; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry*; D008958:Models, Molecular; D010316:Particle Size; D011487:Protein Conformation; D012709:Serum Albumin / Q000037:antagonists & inhibitors* / Q000737:chemistry*; D012996:Solutions; D013329:Structure-Activity Relationship; D013499:Surface Properties
chemical_list: D012709:Serum Albumin; D012996:Solutions; D006046:Gold