Experimental determination of second virial coefficients by small-angle X-ray scattering: a problem revisited

DOI: 10.1007/s00249-019-01404-0

Authors: Tyler Mrozowich (University of Lethbridge) , Donald J. Winzor (University of Queensland) , David J. Scott (University of Nottingham; ISIS Spallation Neutron and Muon Source) , Trushar R. Patel (University of Lethbridge; University of Calgary; University of Alberta)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: European Biophysics Journal , VOL 346

State: Published (Approved)
Published: October 2019
Diamond Proposal Number(s): 16028

Abstract: This investigation examines the validity of employing single-solute theory to interpret SAXS measurements on buffered protein solutions—the current practice despite the necessity to regard the buffer components as additional non-scattering solutes rather than as part of the solvent. The present study of bovine serum albumin in phosphate-buffered saline supplemented with 20–100 g/L sucrose as small cosolute has certainly verified the prediction that the experimentally obtained second virial coefficient should contain protein–cosolute contributions. Nevertheless, the second virial coefficient determined for protein solutions supplemented with high cosolute concentrations on the basis of single-solute theory remains a valid means for identifying conditions conducive to protein crystallization, because the return of a slightly negative second virial coefficient based on single-solute theory 𝐴app2 still establishes the existence of slightly associative interactions between protein molecules, irrespective of the molecular source–protein self-interactions and/or protein–cosolute contributions.

Journal Keywords: Small-angle X-ray scattering; Thermodynamic nonideality; Second virial coefficients; Bovine serum albumin; Small cosolute effects

Subject Areas: Biology and Bio-materials


Instruments: B21-High Throughput SAXS

Added On: 31/10/2019 03:54

Discipline Tags:

Biophysics Life Sciences & Biotech

Technical Tags:

Scattering Small Angle X-ray Scattering (SAXS)