title: Structural Insights into Bound Water in Crystalline Amino Acids: Experimental and Theoretical (17)O NMR.
abstract: We demonstrate here that the (17)O NMR properties of bound water in a series of amino acids and dipeptides can be determined with a combination of nonspinning and magic-angle spinning experiments using a range of magnetic field strengths from 9.4 to 21.1 T. Furthermore, we propose a (17)O chemical shift fingerprint region for bound water molecules in biological solids that is well outside the previously determined ranges for carbonyl, carboxylic, and hydroxyl oxygens, thereby offering the ability to resolve multiple (17)O environments using rapid one-dimensional NMR techniques. Finally, we compare our experimental data against quantum chemical calculations using GIPAW and hybrid-DFT, finding intriguing discrepancies between the electric field gradients calculated from structures determined by X-ray and neutron diffraction.
authors.affiliation: †Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 United States.
authors.forename: Vladimir K
authors.initials: VK
authors.lastname: Michaelis
authors.affiliation: †Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 United States.
authors.forename: Eric G
authors.initials: EG
authors.lastname: Keeler
authors.affiliation: †Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 United States.
authors.forename: Ta-Chung
authors.initials: TC
authors.lastname: Ong
authors.affiliation: ‡Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2 Canada.
authors.forename: Kimberley N
authors.initials: KN
authors.lastname: Craigen
authors.affiliation: †Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 United States.
authors.forename: Susanne
authors.initials: S
authors.lastname: Penzel
authors.affiliation: ‡Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2 Canada.
authors.forename: John E C
authors.initials: JE
authors.lastname: Wren
authors.affiliation: ‡Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2 Canada.
authors.forename: Scott
authors.initials: S
authors.lastname: Kroeker
authors.affiliation: †Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 United States.
authors.forename: Robert G
authors.initials: RG
authors.lastname: Griffin
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D003198:Computer Simulation; D008956:Models, Chemical; D033363:Neutron Diffraction; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D010103:Oxygen Isotopes; D014867:Water / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D000596:Amino Acids; D010103:Oxygen Isotopes; D014867:Water