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Möglich, Andreas ; Joder, Karin ; Kiefhaber, Thomas:
End-to-end distance distributions and intrachain diffusion constants in unfolded polypeptide chains indicate intramolecular hydrogen bond formation.
In: Proceedings of the National Academy of Sciences of the United States of America.
Bd. 103
(2006)
Heft 33
.
- S. 12394-12399.
ISSN 1091-6490
DOI: https://doi.org/10.1073/pnas.0604748103
Abstract
Characterization of the unfolded state is essential for the understanding of the protein folding reaction. We performed time-resolved FRET measurements to gain information on the dimensions and the internal dynamics of unfolded polypeptide chains. Using an approach based on global analysis of data obtained from two different donor-acceptor pairs allowed for the determination of distance distribution functions and diffusion constants between the chromophores. Results on a polypeptide chain consisting of 16 Gly-Ser repeats between the FRET chromophores reveal an increase in the average end-to-end distance from 18.9 to 39.2 Angstrom between 0 and 8 M GdmCl. The increase in chain dimensions is accompanied by an increase in the end-to-end diffusion constant from (3.6 +/- 1.0) x 10(-7) cm(2) s(-1) in water to (14.8 +/- 2.5) x 10(-7) cm(2) s(-1) in 8 M GdmCl. This finding suggests that intrachain interactions in water exist even in very flexible chains lacking hydrophobic groups, which indicates intramolecular hydrogen bond formation. The interactions are broken upon denaturant binding, which leads to increased chain flexibility and longer average end-to-end distances. This finding implies that rapid collapse of polypeptide chains during refolding of denaturant-unfolded proteins is an intrinsic property of polypeptide chains and can, at least in part, be ascribed to nonspecific intramolecular hydrogen bonding. Despite decreased intrachain diffusion constants, the conformational search is accelerated in the collapsed state because of shorter diffusion distances. The measured distance distribution functions and diffusion constants in combination with Szabo-Schulten-Schulten theory were able to reproduce experimentally determined rate constants for end-to-end loop formation.
Weitere Angaben
| Publikationsform: | Artikel in einer Zeitschrift |
|---|---|
| Begutachteter Beitrag: | Ja |
| Zusätzliche Informationen: | PubMed-ID: 9526123 |
| Institutionen der Universität: | Fakultäten > Fakultät für Biologie, Chemie und Geowissenschaften > Fachgruppe Chemie > Lehrstuhl Biochemie > Lehrstuhl Biochemie II - Photobiochemie - Univ.-Prof. Dr. Andreas Möglich Fakultäten Fakultäten > Fakultät für Biologie, Chemie und Geowissenschaften Fakultäten > Fakultät für Biologie, Chemie und Geowissenschaften > Fachgruppe Chemie Fakultäten > Fakultät für Biologie, Chemie und Geowissenschaften > Fachgruppe Chemie > Professur Biochemie Fakultäten > Fakultät für Biologie, Chemie und Geowissenschaften > Fachgruppe Chemie > Lehrstuhl Biochemie |
| Titel an der UBT entstanden: | Nein |
| Themengebiete aus DDC: | 500 Naturwissenschaften und Mathematik > 540 Chemie |
| Eingestellt am: | 20 Mai 2015 06:58 |
| Letzte Änderung: | 05 Sep 2022 07:36 |
| URI: | https://eref.uni-bayreuth.de/id/eprint/13611 |