Probing water-protein contacts in a MMP-12/CGS27023A complex by nuclear magnetic resonance spectroscopy
Abstract Using the case of the catalytic domain of MMP-12 in complex with the known inhibitor CGS27023A, a recently assembled 3D 15N-edited/14N,12C-filtered ROESY experiment is used to monitor and distinguish protein amide protons in fast exchange with bulk water from amide protons close to water molecules with longer residence times, the latter possibly reflecting water molecules of structural or functional importance. The 15N-edited/14N,12C-filtered ROESY spectra were compared to the original 15N-edited/14N,12C-filtered NOESY and the conventional amide-water exchange experiment, CLEANEX. Three protein backbone amide protons experiencing direct dipolar cross relaxation with water in the 15N-edited/14N,12C-filtered ROESY spectrum were assigned. In an ensemble of six crystal structures, two conserved water molecules within 3 Ă? of the three amide protons were identified. These two water molecules are buried into cavities in the protein surface and thus sufficiently slowed down by the protein topology to account for the observed dipolar interaction. Structural analysis of an ensemble of six crystal structures ruled out any exchange-relayed contributions for the amide-water interactions of interest.
- Content Type Journal Article
- Category Article
- Pages 1-8
- DOI 10.1007/s10858-012-9624-7
- Authors
- Helena Kovacs, Bruker BioSpin AG, 8117 Fällanden, Switzerland
- Tatiana Agback, Medivir AB, PO Box 1086, SE-141 22 Huddinge, Sweden
- Johan Isaksson, Drug Discovery and Design, Department of Chemistry, University of Tromsø, 9037 Tromsø, Norway
Source: Journal of Biomolecular NMR