The inverse and direct Hofmeister series of Hen egg lysozyme at pH below isoelectric point (pI) as seen by SAXS

POSTER

Abstract

Protein interaction and aggregation processes are important in understanding many physiological processes in living organisms. Diseases such as Alzheimer’s, Creutzfeldt-Jakob and Parkinson’s are associated with protein or peptide aggregation phenomena. We are focused on determining the shape, size, and nature of interactions between the protein molecules (lysozyme) in solution at low and high salt concentration of various sodium salts at certain pH by using Small-angle X-ray scattering (SAXS).
Results show that for protein at 10mg/ml and 200mg/ml the shape and size of the protein is spherical with radius 15.5 Å and 16.7 Å respectively. At 60mg/ml with 0.1M sodium salt, the shape and size of the protein is ellipsoidal with the average polar radius of 38.5 Å and equatorial radius 15.5Å. There is no interaction among proteins at 10mg/ml and 60mg/ml whereas at 200mg/ml we see a coulomb repulsive interaction with effective radius 20.3 Å. The variation of the polar radius of protein at 60mg/ml at pH 9.0 with 0.1M of various Hofmeister sodium salts shows an elongation of the protein as we go from left to right in the Hofmeister series. We are currently focusing on determining the mechanism of elongation and impact on aggregation in the protein induced by Hofmeister salts.

Presenters

  • Pawan Koirala

    Dept. of Physics, University of Texas at El Paso

Authors

  • Pawan Koirala

    Dept. of Physics, University of Texas at El Paso

  • Alexey Feofanov

    University of Innsbruck, University of Waterloo, Korea University, Okinawa Institute of Science and Technology, University of California - Los Angeles, The University of Manchester, University of Puerto Rico at Humacao, Department of Physics & Electronics, University of Puerto Rico at Cayey, Department of Mathematics-Physics, Oak Ridge National Lab, Max Planck Institute for Chemical Physics of Solids, Department of Physics, University of Puerto Rico, Electrical Engineering Department, University of Arkansas, Department of Physics, University of Arkansas, School of Basic Sciences at IIT Mandi, H.P., India, Computational Biology, Flatiron Institute, Physics, Hong Kong Univ of Sci & Tech, University of California, Los Angeles, Max Planck Inst, Institute for Theoretical Physics, University of Cologne, Department of Physics, Simon Fraser University, Deutsches Elektronen Synchrotron (DESY), Institut fur Theoretische Physik, Univerisitat zu Berlin, Institut fur Physik, Univerisitat zu Berlin, Plymouth State University, The Graduate Center, CUNY, Nordita, KTH Royal Institute of Technology and Stockholm University, Univ of Connecticut - Storrs, Univ Stuttgart, University of Chicago, University of Texas at El Paso, University of Tulsa, California Institute of Technology, Georgia Institute of Technology, Universite Paris Diderot, Laboratoire MPQ, Universita di Trento, BEC Center, ICTP Trieste, Universita di Pisa, Inst of Physics Academia Sinica, Batelle, Cal State Univ- San Bernardino, Chemical Engineering, University of Michigan, QCD Labs, Department of Applied Physics, Aalto University, Yale University, MIT, Harvard Univ, Chemical & Environmental Engineering, University of California, Riverside, University of Frankfurt, Germany, University of Hamburg, Germany, Naval Research Laboratory, Cornell Univ, National Institute for Material Science, U.S. Naval Research Laboratory, Washington DC, Materials Engineering, University of Santa Barbara, Institute of Physics, Chinese Academy of Sciences, Univ of Texas, Arlington, MIT Lincoln Laboratory, University of Sydney, Iowa State University, Purdue University, Kansas State University, University of Maryland, John Hopkins University, Universite de Sherbrooke, Physics, Konkuk University, Perimeter Institute, University of Waterloo, D-Wave, San Jose State University, Université de Sherbrooke, Institute of Physics, EPFL - Lausanne​