Uma estrutura "invisível" de proteína explica o poder das enzimas

sábado, julho 04, 2015

Structural basis for catalytically restrictive dynamics of a high-energy enzyme state

Michael Kovermann, Jörgen Ådén, Christin Grundström, A. Elisabeth Sauer-Eriksson, Uwe H. Sauer & Magnus Wolf-Watz

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Nature Communications 6, Article number: 7644 doi:10.1038/ncomms8644

Received 13 January 2015 Accepted 27 May 2015 Published 03 July 2015



Abstract

An emerging paradigm in enzymology is that transient high-energy structural states play crucial roles in enzymatic reaction cycles. Generally, these high-energy or ‘invisible’ states cannot be studied directly at atomic resolution using existing structural and spectroscopic techniques owing to their low populations or short residence times. Here we report the direct NMR-based detection of the molecular topology and conformational dynamics of a catalytically indispensable high-energy state of an adenylate kinase variant. On the basis of matching energy barriers for conformational dynamics and catalytic turnover, it was found that the enzyme’s catalytic activity is governed by its dynamic interconversion between the high-energy state and a ground state structure that was determined by X-ray crystallography. Our results show that it is possible to rationally tune enzymes’ conformational dynamics and hence their catalytic power—a key aspect in rational design of enzymes catalysing novel reactions.

Subject terms: Biological sciences Biophysics Biochemistry

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