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Real-Time Analysis of Folding upon Binding of a Disordered Protein by Using Dissolution DNP?NMR Spectroscopy.

ABSTRACT: The kinase inhibitory domain of the cell cycle regulatory protein p27Kip1 (p27) was nuclear spin hyperpolarized using dissolution dynamic nuclear polarization (D-DNP). While intrinsically disordered in isolation, p27 adopts secondary structural motifs, including an ?-helical structure, upon binding to cyclin-dependent kinase 2 (Cdk2)/cyclin A. The sensitivity gains obtained with hyperpolarization enable the real-time observation of 13 C?NMR signals during p27 folding upon binding to Cdk2/cyclin A on a time scale of several seconds. Time-dependent intensity changes are dependent on the extent of folding and binding, as manifested in differential spin relaxation. The analysis of signal decay rates suggests the existence of a partially folded p27 intermediate during the timescale of the D-DNP NMR experiment.

SUBMITTER: Ragavan M

PROVIDER: S-EPMC5674774 | biostudies-literature | 2017 Jun

REPOSITORIES: biostudies-literature

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Real-Time Analysis of Folding upon Binding of a Disordered Protein by Using Dissolution DNP NMR Spectroscopy.

Ragavan Mukundan M Iconaru Luigi I LI Park Cheon-Gil CG Kriwacki Richard W RW Hilty Christian C

Angewandte Chemie (International ed. in English) 20170516 25

The kinase inhibitory domain of the cell cycle regulatory protein p27<sup>Kip1</sup> (p27) was nuclear spin hyperpolarized using dissolution dynamic nuclear polarization (D-DNP). While intrinsically disordered in isolation, p27 adopts secondary structural motifs, including an α-helical structure, upon binding to cyclin-dependent kinase 2 (Cdk2)/cyclin A. The sensitivity gains obtained with hyperpolarization enable the real-time observation of <sup>13</sup> C NMR signals during p27 folding upon b ...[more]

PMID: 28508552

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