title: Pressure-induced protein adsorption at aqueous-solid interfaces.
abstract: There seems to be a general relation between the standard Gibbs energy change of unfolding, ΔG°unf, of a protein and its affinity to aqueous-solid interfaces. So-called "hard" proteins (ΔG°unf is large) are found to adsorb less strongly to such interfaces than "soft" proteins (ΔG°unf is small). Here, we provide direct support for this rule by using high pressure to modulate the folding stability of a protein. We have performed high-pressure total internal reflection fluorescence (HP-TIRF) spectroscopy and high-pressure neutron reflectometry (HP-NR) to measure the degree of adsorption and the structure of lysozyme on planar solid surfaces as a function of pressure for the first time. By carrying out these experiments at hydrophilic and hydrophobic surfaces with varying concentrations of glycerol, we have found strong evidence that ΔG°unf has indeed a direct influence. At high pressures, there is a larger degree of lysozyme adsorption, probably because lysozyme becomes a "soft" protein under these conditions. The results of this study demonstrate that high pressure is a very useful tool to explore thermodynamics of protein-interface interactions.
authors.affiliation: Fakultät Chemie, TU Dortmund University, D-44221 Dortmund, Germany.
authors.forename: Juny
authors.initials: J
authors.lastname: Koo
authors.forename: Mirko
authors.initials: M
authors.lastname: Erlkamp
authors.forename: Sebastian
authors.initials: S
authors.lastname: Grobelny
authors.forename: Roland
authors.initials: R
authors.lastname: Steitz
authors.forename: Claus
authors.initials: C
authors.lastname: Czeslik
mesh_terms: D000327:Adsorption; D057927:Hydrophobic and Hydrophilic Interactions; D011312:Pressure; D011506:Proteins / Q000737:chemistry*
chemical_list: D011506:Proteins