Prediction of favourable sites for spin labelling of proteins

Article type: Research Article

Authors: Polyhach, Yevhen | Jeschke, Gunnar

Affiliations: Laboratory of Physical Chemistry, ETH Zurich, Zurich, Switzerland

Note: [] Corresponding author: Gunnar Jeschke, Laboratory of Physical Chemistry, ETH Zurich, Wolfgang-Pauli-Strasse 10, CH-8093 Zurich, Switzerland. Tel.: +41 44 632 5702; Fax: +41 44 633 1448; E-mail: [email protected].

Abstract: Electron paramagnetic resonance studies on diamagnetic proteins are based on site-directed spin labelling and require relatively much effort for engineering cystein point mutations as well as expressing and labelling the protein. Therefore, it is advantageous to predict those sites and pairs of sites that can provide the most precise and most reliable information on accessibility and distances. Systematic site scans based on a rotamer library approach for spin label side groups allow for such predictions. Figures of merit are defined that can be used to rank sites according to their potential suitability in studies of structure and structural changes. Such site scans can still provide useful results if only a backbone model and the amino acid sequence of the protein are known.

Keywords: EPR spectroscopy, site-directed spin labelling, membrane proteins, molecular modelling, distance measurements

DOI: 10.3233/SPE-2010-0490

Journal: Spectroscopy, vol. 24, no. 6, pp. 651-659, 2010