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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.

SUBMITTER: Michaelis VK

PROVIDER: S-EPMC4894719 | biostudies-literature | 2015 Jun

REPOSITORIES: biostudies-literature

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Structural Insights into Bound Water in Crystalline Amino Acids: Experimental and Theoretical (17)O NMR.

Michaelis Vladimir K VK Keeler Eric G EG Ong Ta-Chung TC Craigen Kimberley N KN Penzel Susanne S Wren John E C JE Kroeker Scott S Griffin Robert G RG

The journal of physical chemistry. B 20150610 25

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 abilit ...[more]

PMID: 25996165

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