Cytochrome b562 folding triggered by electron transfer: approaching the speed limit for formation of a four-helix-bundle protein

P Wittung-Stafshede; J C Lee; J R Winkler; H B Gray

doi:10.1073/pnas.96.12.6587

Cytochrome b562 folding triggered by electron transfer: approaching the speed limit for formation of a four-helix-bundle protein

Proc Natl Acad Sci U S A. 1999 Jun 8;96(12):6587-90. doi: 10.1073/pnas.96.12.6587.

Authors

P Wittung-Stafshede¹, J C Lee, J R Winkler, H B Gray

Affiliation

¹ Beckman Institute, California Institute of Technology, Pasadena, CA 91125, USA.

Abstract

Ferrocytochrome b562 [Fe(II)cyt b562] folding can be triggered by photoinduced electron transfer to unfolded Fe(III)cyt b562 in 2-3 M guanidine hydrochloride solutions. The folding rates increase with decreasing guanidine hydrochloride; the extrapolated time constant for this folding process in the absence of denaturant (5 micros) is near the predicted value for intrachain diffusion. The relatively smooth energy landscape indicated for Fe(II)cyt b562 folding accords with the helical, highly symmetrical structure of the protein.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Cytochrome b Group / chemistry*
Electron Transport*
Escherichia coli
Escherichia coli Proteins*
Protein Folding*

Substances

Cytochrome b Group
Escherichia coli Proteins
cytochrome b562, E coli