Characterization of different water pools in solid-state NMR protein samples
 

Characterization of different water pools in solid-state NMR protein samples


Abstract We observed and characterized two distinct signals originating from different pools of water protons in solid-state NMR protein samples, namely from crystal water which exchanges polarization with the protein (on the NMR timescale) and is located in the protein-rich fraction at the periphery of the magic-angle spinning (MAS) sample container, and supernatant water located close to the axis of the sample container. The polarization transfer between the water and the protein can be probed by two-dimensional exchange spectroscopy, and we show that the supernatant water does not interact with protein on the timescale of the experiments. The two water pools have different spectroscopic properties, including resonance frequency, longitudinal, transverse and rotating frame relaxation times. The supernatant water can be removed almost completely physically or can be frozen selectively. Both measures lead to an enhancement of the quality factor of the probe circuit, accompanied by an improvement of the experimental signal/noise, and greatly simplify solvent-suppression by substantially reducing the water signal. We also present a tool, which allows filling solid-state NMR sample containers in a more efficient manner, greatly reducing the amount of supernatant water and maximizing signal/noise.

• Content Type Journal Article
• Pages 319-327
• DOI 10.1007/s10858-009-9374-3
• Authors
  • Anja Böckmann, Université de Lyon, UMR 5086 CNRS/UCB-Lyon 1 Institut de Biologie et Chimie des Protéines 7 passage du Vercors 69367 Lyon France
  • Carole Gardiennet, Université de Lyon, UMR 5086 CNRS/UCB-Lyon 1 Institut de Biologie et Chimie des Protéines 7 passage du Vercors 69367 Lyon France
  • René Verel, ETH Zürich Physical Chemistry Wolfgang-Pauli-Strasse 10 8093 Zurich Switzerland
  • Andreas Hunkeler, ETH Zürich Physical Chemistry Wolfgang-Pauli-Strasse 10 8093 Zurich Switzerland
  • Antoine Loquet, Université de Lyon, UMR 5086 CNRS/UCB-Lyon 1 Institut de Biologie et Chimie des Protéines 7 passage du Vercors 69367 Lyon France
  • Guido Pintacuda, Université de Lyon, CNRS/ENS Lyon/UCB-Lyon 1 Centre RMN Ã* Très Hauts Champs, 5 rue de la Doua 69100 Villeurbanne France
  • Lyndon Emsley, Université de Lyon, CNRS/ENS Lyon/UCB-Lyon 1 Centre RMN Ã* Très Hauts Champs, 5 rue de la Doua 69100 Villeurbanne France
  • Beat H. Meier, ETH Zürich Physical Chemistry Wolfgang-Pauli-Strasse 10 8093 Zurich Switzerland
  • Anne Lesage, Université de Lyon, CNRS/ENS Lyon/UCB-Lyon 1 Centre RMN Ã* Très Hauts Champs, 5 rue de la Doua 69100 Villeurbanne France

• • Journal Journal of Biomolecular NMR
  • Online ISSN 1573-5001
  • Print ISSN 0925-2738
  • Journal Volume Volume 45
  • Journal Issue Volume 45, Number 3

Source: Journal of Biomolecular NMR