Solution NMR of Polypeptides Hyperpolarized by Dynamic Nuclear Polarization.

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Solution NMR of Polypeptides Hyperpolarized by Dynamic Nuclear Polarization.

Solution NMR of Polypeptides Hyperpolarized by Dynamic Nuclear Polarization.

Anal Chem. 2011 Jun 7;

Authors: Ragavan M, Chen HY, Sekar G, Hilty C

Hyperpolarization of nuclear spins through techniques such as Dynamic Nuclear Polarization (DNP) can greatly increase the signal to noise ratio in NMR measurements, thus eliminating the need for signal averaging. This enables the study of many dynamic processes which would otherwise not be amenable to study by NMR spectroscopy. A report of solid-to-liquid state DNP of a short peptide, Bacitracin A as well as of a full-length protein, L23, is presented here. The polypeptides are hyperpolarized at low temperature, and dissolved for NMR signal acquisition in the liquid state in mixtures of organic solvent and water. Signal enhancements of 300-2000 are obtained in partially deuterated polypeptide when hyperpolarized on 13C, and of 30-180 when hyperpolarized on 1H. A simulated spectrum is used to identify different resonances in the hyperpolarized 13C spectra, and the relation between observed signal enhancement for various groups in the protein and relaxation parameters measured from the hyperpolarized samples are discussed. Thus far, solid-to-liquid state DNP has been used in conjunction with small molecules. The results presented here, however, demonstrate the feasibility of hyperpolarizing larger proteins, with potential applications towards the study of protein folding or macromolecular interactions.

PMID: 21651293 [PubMed - as supplied by publisher]



Source: PubMed