Protein and solvent dynamics of the water-soluble chlorophyll-binding protein (WSCP)

¹ Institute of Physical Energetics, Riga, Latvia
² Paul-Scherrer Institute, Villigen, Switzerland
³ Institute of General Botany, Johannes Gutenberg University Mainz, Germany
⁴ Technical University, Max-Volmer-Laboratories for Biophysical Chemistry, Berlin, Germany
⁵ Institute of Physics, University of Tartu, Tartu, Estonia

^a Corresponding author: pieper@ut.ee

Published online: 23 January 2015

Abstract

This study presents quasielastic neutron scattering data of the water-soluble chlorophyll-binding protein (WSCP) and the corresponding buffer solution at room temperature. The contributions of protein and buffer solution to the overall scattering are carefully separated. Otherwise, the fast water dynamics dominating the buffer contribution is likely to mask the slow protein dynamics. In the case of WSCP, the protein scattering can be described by two contributions: i) internal protein dynamics represented by a diffusion in a sphere with an average radius of 2.7 Å and ii) global (Brownian) diffusion of the WSCP macromolecule with an upper limit for the translational diffusion coefficient of 9.4 ⋅ 10⁻⁷ cm²/s.