Folding-unfolding of FN-III domains in tenascin : an elastically coupled two-state system

In a single-molecule atomic force microscopy (AFM) experiment, the tenascin molecule is stretched by an external force causing an elongation which is due to the unfolding of the FN-III modules. The features of the force-extension curves depend on the pulling speed and show a saw-tooth pattern (lower speeds) or a smooth pattern (higher speeds). In any case, the unfolded domains are elastically coupled to the unfolded modules, acting as transmitters of the external force. In this communication, the folding-unfolding process of the FN-III domains in tenascin is studied using reaction rate theory and a simple two-state model. The main hypothesis of the study is that, at microscopic level, the force needed to unfold a domain and the unfolding rate (unfolding velocity) can mimic the macroscopic process of measurement by AFM. As the external force is applied, the probability of unfolding increases as dictated by the reaction rate theory. Within this context, a relationship between the unfolding force and the unfolding velocity is obtained. The latter relation will describe microscopically the process in a phenomenological fashion. Moreover, while relating the results of this study with other experimental (AFM measurements) and theoretical (Monte Carlo simulations) data, we found that the graph of unfolding force-unfolding velocity is similar to that of external force-pulling velocity. The refolding process can also be studied within this model and the results show similar trends. The latter suggests a generic and universal behavior of such kind of molecular domains at least in the light of the proposed model.

Medienart:

Artikel

Erscheinungsjahr:

2003

Erschienen:

2003

Enthalten in:

Zur Gesamtaufnahme - volume:36

Enthalten in:

Journal of biomechanics - 36(2003), 11 vom: 15. Nov., Seite 1733-7

Sprache:

Englisch

Beteiligte Personen:

Marín, J L [VerfasserIn]
Muñiz, J [VerfasserIn]
Huerta, M [VerfasserIn]
Trujillo, X [VerfasserIn]

Themen:

Comparative Study
Evaluation Study
Journal Article
Research Support, Non-U.S. Gov't
Tenascin
Validation Study

Anmerkungen:

Date Completed 10.06.2004

Date Revised 10.12.2019

published: Print

Citation Status MEDLINE

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM142630748