Neutron scattering studies on protein dynamics using the human myelin peripheral membrane protein P2

¹ Faculty of Biochemistry and Molecular Medicine & Biocenter Oulu, University of Oulu, Oulu, Finland
² Centre for Structural Systems Biology, Helmholtz Centre for Infection Research (CSSB-HZI), German Electron Synchrotron (DESY), Hamburg, Germany
³ Department of Chemistry, University of Hamburg, Hamburg, Germany
⁴ Institut Laue-Langevin (ILL), 71 avenue des Martyrs, CS 20156, 38042 Grenoble Cedex 9, France
⁵ CNR-IOM, OGG, 71 avenue des Martyrs, CS 20156, 38042 Grenoble Cedex 9, France

^a Corresponding author: saara.laulumaa@oulu.fi

Published online: 23 January 2015

Abstract

Myelin is a multilayered proteolipid membrane structure surrounding selected axons in the vertebrate nervous system, which allows the rapid saltatory conduction of nerve impulses. Deficits in myelin formation and maintenance may lead to chronic neurological disease. P2 is an abundant myelin protein from peripheral nerves, binding between two apposing lipid bilayers. We studied the dynamics of the human myelin protein P2 and its mutated P38G variant in hydrated powders using elastic incoherent neutron scattering. The local harmonic vibrations at low temperatures were very similar for both samples, but the mutant protein had increased flexibility and softness close to physiological temperatures. The results indicate that a drastic mutation of proline to glycine at a functional site can affect protein dynamics, and in the case of P2, they may explain functional differences between the two proteins.