Dynamic Nuclear Polarization / solid-state NMR of membranes. Thermal effects and sample geometry

Evgeniy Sergeevich Salnikov; Fabien Aussenac; Sebastian Abel; Armin Purea; Paul Tordo; Olivier Ouari; Burkhard Bechinger

doi:10.1016/j.ssnmr.2019.03.004

Dynamic Nuclear Polarization / solid-state NMR of membranes. Thermal effects and sample geometry

Solid State Nucl Magn Reson. 2019 Aug:100:70-76. doi: 10.1016/j.ssnmr.2019.03.004. Epub 2019 Mar 22.

Authors

Evgeniy Sergeevich Salnikov¹, Fabien Aussenac², Sebastian Abel³, Armin Purea⁴, Paul Tordo³, Olivier Ouari³, Burkhard Bechinger⁵

Affiliations

¹ Institute of Chemistry, University of Strasbourg / CNRS, UMR7177, 67070, Strasbourg, France.
² Bruker BioSpin, Wissembourg, France.
³ Aix-Marseille University, CNRS, UMR 7273, Institut de Chimie Radicalaire, 13013, Marseille, France.
⁴ Bruker BioSpin, Rheinstetten, Germany.
⁵ Institute of Chemistry, University of Strasbourg / CNRS, UMR7177, 67070, Strasbourg, France. Electronic address: [email protected].

PMID: 30995597
DOI: 10.1016/j.ssnmr.2019.03.004

Abstract

Whereas specially designed dinitroxide biradicals, reconstitution protocols, oriented sample geometries and NMR probes have helped to much increase the DNP enhancement factors of membrane samples they still lag considerably behind those obtained from glasses made of protein solutions. Here we show that not only the MAS rotor material but also the distribution of the membrane samples within the NMR rotor have a pronounced effect on the DNP enhancement. These observations are rationalized with the cooling efficiency and the internal properties of the sample, monitored by their T₁ relaxation, microwave ON versus OFF signal intensities and DNP effect. The data are suggestive that for membranes the speed of cooling has a pronounced effect on the membrane properties and concomitantly the distribution of biradicals within the sample.

Publication types

Research Support, Non-U.S. Gov't