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A partially folded intermediate species of the beta-sheet protein apo-pseudoazurin is trapped during proline-limited folding

Reader, JS, van Nuland, NAJ, Thompson, GS, Ferguson, SJ, Dobson, CM, Radford, SE (2001) A partially folded intermediate species of the beta-sheet protein apo-pseudoazurin is trapped during proline-limited folding. Protein Science, 10 . pp. 1216-1224. ISSN 0961-8368. (doi:10.1110/ps.52801) (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided)

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Official URL
https://doi.org/10.1110/ps.52801

Abstract

The folding of apo-pseudoazurin, a 123-residue, predominantly beta-sheet protein with a complex Greek key topology, has been investigated using several biophysical techniques. Kinetic analysis of refolding using far- and near-ultraviolet circular dichroism (UV CD) shows that the protein folds slowly to the native state with rate constants of 0.04 and 0.03 min(-1), respectively, at pH 7.0 and at 15 degrees C. This process has an activation enthalpy of approximately 90 kJ/mole and is catalyzed by cyclophilin A, indicating that folding is limited by trans-cis proline isomerization, presumably around the Xaa-Pro 20 bond that is in the cis isomer in the native state. Before proline isomerization, an intermediate accumulates during folding. This species has a substantial signal in the far-UV CD, a nonnative signal in the near-UV CD, exposed hydrophobic surfaces (judged by 1-anilino naphthalenesulphonate binding), a noncooperative denaturation transition, and a dynamic structure (revealed by line broadening on the nuclear magnetic resonance time scale). We compare the properties of this intermediate with partially folded states of other proteins and discuss its role in folding of this complex Greek key protein.

Item Type: Article
DOI/Identification number: 10.1110/ps.52801
Subjects: Q Science > QP Physiology (Living systems) > QP517 Biochemistry
Divisions: Faculties > Sciences > School of Biosciences
Depositing User: G. Thompson
Date Deposited: 23 Jan 2019 17:35 UTC
Last Modified: 30 May 2019 08:47 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/71825 (The current URI for this page, for reference purposes)
Thompson, GS: https://orcid.org/0000-0001-9399-7636
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