title: The second virial coefficient as a predictor of protein aggregation propensity: A self-interaction chromatography study.
abstract: The second osmotic virial coefficients (b2) of four proteins - lysozyme, recombinant human lactoferrin, concanavalin A and catalase were measured by self-interaction chromatography (SIC) in solutions of varying salt type, concentration and pH. Protein aggregate sizes based on the initial hydrodynamic radius of the protein solution species present were measured using dynamic light scattering, and the relationship between b2 and protein aggregate size was studied. A linear correlation was established between b2 values and protein aggregate hydrodynamic size for all proteins, and for almost all solution conditions. Aggregate sizes of <∼10nm, indicative of non-aggregated protein systems, were consistently observed to have b2 values >0. The observed b2 trends as a function of solution conditions were very much protein dependent, with notable trends including the existence of attractive interactions (negative b2 values) at low ionic strengths for catalase and concanavalin A, and the highly positive b2 values observed for lactoferrin over a wide range of solution conditions, reflecting lactoferrin's innately high stability. It is concluded that the quantification of protein-protein interactions using SIC based b2 data is a potentially valuable screening tool for predicting protein aggregation propensity.
authors.affiliation: Surfaces and Particle Engineering Laboratory, Department of Chemical Engineering, Imperial College London, London SW7 2BY, UK.
authors.forename: A
authors.initials: A
authors.lastname: Quigley
authors.affiliation: Surfaces and Particle Engineering Laboratory, Department of Chemical Engineering, Imperial College London, London SW7 2BY, UK. Electronic address: d.r.williams@imperial.ac.uk.
authors.forename: D R
authors.initials: DR
authors.lastname: Williams
mesh_terms: D000465:Algorithms; D000818:Animals; D002374:Catalase / Q000737:chemistry*; D002417:Cattle; D002645:Chickens; D003208:Concanavalin A / Q000737:chemistry*; D004339:Drug Compounding; D004355:Drug Stability; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D055767:Immobilized Proteins / Q000737:chemistry; D007781:Lactoferrin / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008863:Microspheres; D008958:Models, Molecular; D009113:Muramidase / Q000737:chemistry*; D066329:Protein Aggregates; D054730:Protein Interaction Domains and Motifs; D055550:Protein Stability; D011994:Recombinant Proteins / Q000737:chemistry; D012996:Solutions
chemical_list: D004800:Enzymes, Immobilized; D055767:Immobilized Proteins; C490098:LTF protein, human; D066329:Protein Aggregates; D011994:Recombinant Proteins; D012996:Solutions; D003208:Concanavalin A; D002374:Catalase; C421864:hen egg lysozyme; D009113:Muramidase; D007781:Lactoferrin
keywords: Catalase; Concanavalin A; Lactoferrin; Lysozyme; Protein aggregation; Protein stability; Protein–protein interactions; Second virial coefficient; Self-interaction chromatography; b(2)