Titlebar

Export bibliographic data
Literature by the same author
plus on the publication server
plus at Google Scholar

 

A thermodynamic coupling mechanism for GroEL-mediated unfolding

Title data

Walter, Stefan ; Lorimer, George H. ; Schmid, Franz X.:
A thermodynamic coupling mechanism for GroEL-mediated unfolding.
In: Proceedings of the National Academy of Sciences of the United States of America. Vol. 93 (3 September 1996) Issue 18 . - pp. 9425-9430.
ISSN 1091-6490

Official URL: Volltext

Abstract in another language

Chaperonins prevent the aggregation of partially folded or misfolded forms of a protein and, thus, keep it competent for productive folding. It was suggested that GroEL, the chaperonin of Escherichia coli, exerts this function 1 unfolding such intermediates, presumably in a catalytic fashion. We investigated the kinetic mechanism of GroEL-induced protein unfolding by using a reduced and carbamidomethylated variant of RNase T1, RCAM-T1, as a substrate. RCAM-T1 cannot fold to completion, because the two disulfide bonds are missing, and it is, thus, a good model for long-lived folding intermediates. RCAM-T1 unfolds when GroEL is added, but GroEL does not change the microscopic rate constant of unfolding, ruling out that it catalyzes unfolding. GroEL unfolds RCAM-T1 because it binds with high affinity to the unfolded form of the protein and thereby shifts the overall equilibrium toward the unfolded state. GroEL can unfold a partially folded or misfolded intermediate by this thermodynamic coupling mechanism when the Gibbs free energy of the binding to GroEL is larger than the conformational stability of the intermediate and when the rate of its unfolding is high.

Further data

Item Type: Article in a journal
Refereed: Yes
Additional notes: PubMed-ID: 8425108
Institutions of the University: Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Chemistry > Former Professors > Professorship Biochemistry - Univ.-Prof. Dr. Franz Xaver Schmid
Faculties
Faculties > Faculty of Biology, Chemistry and Earth Sciences
Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Chemistry
Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Chemistry > Professorship Biochemistry
Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Chemistry > Former Professors
Result of work at the UBT: Yes
DDC Subjects: 500 Science > 540 Chemistry
Date Deposited: 18 May 2015 08:33
Last Modified: 18 May 2015 08:33
URI: https://eref.uni-bayreuth.de/id/eprint/13519