Membrane Proteins in Bulk Solution Can Be Used for Quasi-Elastic Neutron Scattering Studies: The Case for the Photochemical Reaction Center

摘要

The potential to measure the internal dynamics of a membrane protein, the bacterial photochemical reaction center (RC) from the photosynthetic bacterium Rhodobacter sphaeroides, was investigated by incoherent quasi-elastic neutron scattering (IQENS) and entron spin-echo spectroscopy. To isolate and maximize the scattering intensity attributed to the protein, selective deuteration was employed. This deuteration was achieved by embedding detergent-purified RC proteins in a solution containing perdeuterated D_(28)-n-octyl-β-D-glucopyranoside, a sugar-hydroxy detergent. Therefore, the IQENS signal essentially arises only from the established that with a suitable biochemical protocol detailed measurements on the internal dynamics of any integral membrane protein can be undertaken.