title: Probing internal water molecules in proteins using two-dimensional 19F-1H NMR.
abstract: A simple approach for detecting internal water molecules in proteins in solution is described. This approach combines 19F-detected heteronuclear Overhauser and exchange spectroscopy (HOESY) with site-specific 19F substitution. The model system employed was intestinal fatty acid-binding protein complexed with [2-mono-19F]-palmitate. An intense cross peak was observed between the fluorine and a buried water molecule, as defined in the 1.98 A crystal structure of the complex. From HOESY spectra, the fluorine-water distance was estimated to be 2.1 A, in agreement with the crystal structure. This approach may be applicable to macromolecules that are too large for 1H-detected NMR methods.
authors.affiliation: Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110-1093, USA.
authors.forename: D P
authors.initials: DP
authors.lastname: Cistola
authors.forename: K B
authors.initials: KB
authors.lastname: Hall
mesh_terms: D000818:Animals; D001665:Binding Sites; D002352:Carrier Proteins / Q000737:chemistry; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids / Q000378:metabolism; D005461:Fluorine / Q000737:chemistry; D006859:Hydrogen / Q000737:chemistry; D046911:Macromolecular Substances; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008958:Models, Molecular; D015394:Molecular Structure; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D011506:Proteins / Q000737:chemistry*; D051381:Rats; D012996:Solutions; D014867:Water / Q000737:chemistry*
chemical_list: D002352:Carrier Proteins; C490174:Fabp7 protein, rat; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids; D046911:Macromolecular Substances; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D011506:Proteins; D012996:Solutions; D014867:Water; D005461:Fluorine; D006859:Hydrogen