Format

Send to

Choose Destination
See comment in PubMed Commons below
Proc Natl Acad Sci U S A. 2000 Mar 14;97(6):2527-32.

Protein folding and unfolding on a complex energy landscape.

Author information

1
Center for Nonlinear Studies, MS B258, and Bioscience Division, MS J586, Los Alamos National Laboratory, Los Alamos, NM 87545, USA.

Abstract

Recent theories of protein folding suggest that individual proteins within a large ensemble may follow different routes in conformation space from the unfolded state toward the native state and vice versa. Herein, we introduce a new type of kinetics experiment that shows how different unfolding pathways can be selected by varying the initial reaction conditions. The relaxation kinetics of the major cold shock protein of Escherichia coli (CspA) in response to a laser-induced temperature jump are exponential for small temperature jumps, indicative of folding through a two-state mechanism. However, for larger jumps, the kinetics become strongly nonexponential, implying the existence of multiple unfolding pathways. We provide evidence that both unfolding across an energy barrier and diffusive downhill unfolding can occur simultaneously in the same ensemble and provide the experimental requirements for these to be observed.

PMID:
10681466
PMCID:
PMC15962
DOI:
10.1073/pnas.040580397
[Indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Support Center