The results described in parts (1-3) of corresponding summary in last year's report (copied below) were written up and published. The results described in part (4), obtained in an extramural collaboration with T. Scherer of Genentech, are in the process of being written up for publication. -------------------------- From 2007-2008 report: (1) A newly developed apparatus for the performance of automated batch light scattering measurements, with special application for the characterization of the concentration dependence of scattering intensity in highly concentrated protein solutions, initially described in last year's report, has been further improved. (2) Using the newly developed apparatus, the concentration-dependent scattering of three globular proteins, BSA, ovalbumin, and ovomucoid, and binary mixtures of all three proteins has been measured at concentrations of up to 120 g/L. The concentration dependence of scattering in solutions of both pure protein and binary mixtures may be satisfactorily described over the entire range of concentration by a model in which each species is represented by an equivalent hard spherical particle, the size of which reflects both hard steric and soft repulsive intermolecular interactions. (3) Using the newly developed apparatus, the concentration-dependent scattering of chymotrypsin A has been measured at concentration up to >60 g/L at three different pH values. The concentration dependence may be described by an effective hard sphere model that allows for the equilibrium association of monomeric chymotrypsin A to form a dimer and a pentamer or hexamer depending upon pH. (4) The concentration dependence of light scattering of solutions of two different monoclonal IgGs over a concentration range of up to over 150 g/L at several different salt concentrations ranging from 40 to 600 mM NaCl has been analyzed in the context of an effective hard particle model allowing for equilibrium self-association. The data are well fit by an effective hard sphere model that allows for the equilibrium association of monomeric IgG to form a dimer and a tetramer, pentamer, or hexamer, depending upon salt concentration.

Project Start
Project End
Budget Start
Budget End
Support Year
3
Fiscal Year
2009
Total Cost
$191,197
Indirect Cost
City
State
Country
Zip Code
Wu, Di; Minton, Allen P (2013) Compensating effects of urea and trimethylamine-N-oxide on the heteroassociation of ?-chymotrypsin and soybean trypsin inhibitor. J Phys Chem B 117:3554-9
Minton, Allen P (2013) Quantitative assessment of the relative contributions of steric repulsion and chemical interactions to macromolecular crowding. Biopolymers 99:239-44
Wu, Di; Minton, Allen P (2013) Quantitative characterization of the compensating effects of trimethylamine-N-oxide and guanidine hydrochloride on the dissociation of human cyanmethmoglobin. J Phys Chem B 117:9395-9
Wu, Di; Minton, Allen P (2013) Quantitative characterization of the interaction between sucrose and native proteins via static light scattering. J Phys Chem B 117:111-7
Grupi, Asaf; Minton, Allen P (2012) Capillary viscometer for fully automated measurement of the concentration and shear dependence of the viscosity of macromolecular solutions. Anal Chem 84:10732-6
Minton, Allen P (2012) Hard quasispherical particle models for the viscosity of solutions of protein mixtures. J Phys Chem B 116:9310-5
Fernández, Cristina; Minton, Allen P (2011) Effect of nonadditive repulsive intermolecular interactions on the light scattering of concentrated protein-osmolyte mixtures. J Phys Chem B 115:1289-93
Rivas, Germán; Minton, Allen P (2011) Beyond the second virial coefficient: Sedimentation equilibrium in highly non-ideal solutions. Methods 54:167-74
Fodeke, Adedayo A; Minton, Allen P (2010) Quantitative characterization of polymer-polymer, protein-protein, and polymer-protein interaction via tracer sedimentation equilibrium. J Phys Chem B 114:10876-80
Fernandez, Cristina; Minton, Allen P (2009) Static light scattering from concentrated protein solutions II: experimental test of theory for protein mixtures and weakly self-associating proteins. Biophys J 96:1992-8

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