A Structural Ensemble for the Enzyme Cyclophilin Reveals an Orchestrated Mode of Action at Atomic Resolution

Author(s)
Celestine N Chi, Beat Vögeli, Stefan Bibow, Dean Strotz, Julien Orts, Peter Güntert, Roland Riek
Abstract

For enzyme activity, an exact structural and motional orchestration of the active site and its surroundings is believed to be key. In order to reveal such possible phenomena at atomic resolution on the basis of experimental evidence, an experimental restraint driven two-state ensemble of the prototypical enzyme cyclophilin was determined by using a recently introduced exact NOE approach. The ensemble description reveals the presence of an open and a closed state of cyclophilin, which is indicative of large-scale correlated motion. In the open state, the catalytic site is preorganized for catalysis, thus suggesting the mechanism of action to be conformational sampling, while the ligand-binding loop appears to act through an induced fit mechanism. This finding is supported by affinity measurements of a cyclophilin designed to be more open. Overall, more than 60–70 % of the side-chain conformations of cyclophilin appear to be correlated.

Organisation(s)
External organisation(s)
Eidgenössische Technische Hochschule Zürich, Johann Wolfgang Goethe-Universität Frankfurt am Main
Journal
Angewandte Chemie (International Edition)
Volume
54
Pages
11657-11661
No. of pages
5
ISSN
1433-7851
DOI
https://doi.org/10.1002/anie.201503698
Publication date
09-2015
Peer reviewed
Yes
Austrian Fields of Science 2012
106006 Biophysics, 106002 Biochemistry
Keywords
ASJC Scopus subject areas
Biophysics, Biochemistry, General Chemistry, Catalysis
Portal url
https://ucrisportal.univie.ac.at/en/publications/4d422022-05d6-455c-9537-e96528a48266