Session J10: Protein-Protein Interaction and Protein Aggregation

11:15 AM–2:15 PM, Tuesday, March 16, 2010
Room: A106

Sponsoring Unit: DBP
Chair: Ka Yee Lee, University of Chicago

Abstract ID: BAPS.2010.MAR.J10.13

Abstract: J10.00013 : Neutron scattering and phase separation of Gamma-B crystallin vs. pH, ionic strength and protein concentration

1:39 PM–1:51 PM

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Authors:

  George Thurston
    (Rochester Institute of Technology)

  K. Michael Martini
    (Rochester Institute of Technology)

  Kenneth Desmond
    (Emory University)

  Elias Putzig
    (Rochester Institute of Technology)

  Zachary Dell
    (Rochester Institute of Technology)

  Dawn Carter
    (Rochester Institute of Technology)

  Dawn Hollenbeck
    (Rochester Institute of Technology)

  Nicholas Dexter
    (Rochester Institute of Technology)

  Andreas Langner
    (Rochester Institute of Technology)

  David Ross
    (Rochester Institute of Technology)

  Anthony Harkin
    (Rochester Institute of Technology)

  Edward Nelson
    (Rochester Institute of Technology)

  Malin Zackrisson-Oskolkova
    (Lund University)

  Anna Stradner
    (Adolphe Merkle Institute)

  Nicolas Dorsaz
    (Adolphe Merkle Institute)

  Giuseppe Foffi
    (EPFL)

  Peter Schurtenberger
    (Adolphe Merkle Institute)

We study the pH, ionic strength and concentration dependence of liquid-liquid phase separation and neutron scattering of the eye lens protein Gamma-B crystallin. At pH 7, lowering ionic strength raises the cloud points. Neutron scattering indicates anisotropic protein interactions, in agreement with prior information. At lower pH phase separation disappears, and protein repulsions increase at low ionic strength. We seek to evaluate the roles of (i) patterned charge regulation, (ii) biasing of relative protein orientation due to local charge patches, and (iii) screened net protein charge for these phenomena. We apply a grand-canonical partition function model for charge regulation and other interactions, as input to Monte Carlo and neutron scattering computations.

To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2010.MAR.J10.13