title: Extended Law of Corresponding States Applied to Solvent Isotope Effect on a Globular Protein.
abstract: Investigating proteins with techniques such as NMR or neutron scattering frequently requires the partial or complete substitution of D2O for H2O as a solvent, often tacitly assuming that such a solvent substitution does not significantly alter the properties of the protein. Here, we report a systematic investigation of the solvent isotope effect on the phase diagram of the lens protein γB-crystallin in aqueous solution as a model system exhibiting liquid-liquid phase separation. We demonstrate that the observed strong variation of the critical temperature Tc can be described by the extended law of corresponding states for all H2O/D2O ratios, where scaling of the temperature by Tc or the reduced second virial coefficient accurately reproduces the binodal, spinodal, and osmotic compressibility. These findings highlight the impact of H2O/D2O substitution on γB-crystallin properties and warrant further investigations into the universality of this phenomenon and its underlying mechanisms.
authors.affiliation: Physical Chemistry, Department of Chemistry, Lund University , SE-22100 Lund, Sweden.
authors.forename: Saskia
authors.initials: S
authors.lastname: Bucciarelli
authors.affiliation: Physical Chemistry, Department of Chemistry, Lund University , SE-22100 Lund, Sweden.|Adolphe Merkle Institute (AMI), University of Fribourg , CH-1700 Fribourg, Switzerland.
authors.forename: Najet
authors.initials: N
authors.lastname: Mahmoudi
authors.affiliation: Physical Chemistry, Department of Chemistry, Lund University , SE-22100 Lund, Sweden.
authors.forename: Lucía
authors.initials: L
authors.lastname: Casal-Dujat
authors.affiliation: Physical Chemistry, Department of Chemistry, Lund University , SE-22100 Lund, Sweden.
authors.forename: Marie
authors.initials: M
authors.lastname: Jéhannin
authors.affiliation: Adolphe Merkle Institute (AMI), University of Fribourg , CH-1700 Fribourg, Switzerland.
authors.forename: Corinne
authors.initials: C
authors.lastname: Jud
authors.affiliation: Physical Chemistry, Department of Chemistry, Lund University , SE-22100 Lund, Sweden.
authors.forename: Anna
authors.initials: A
authors.lastname: Stradner
mesh_terms: D017666:Deuterium Oxide / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D013696:Temperature; D014867:Water / Q000737:chemistry; D038222:gamma-Crystallins / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D012997:Solvents; C107738:crystallin, gammaB; D038222:gamma-Crystallins; D014867:Water; D017666:Deuterium Oxide