help button home button Biophys. J.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS

Biophysical Journal 54: 577-586 (1988)
© 1988 the Biophysical Society

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Gryczynski, I
Right arrow Articles by Lakowicz, J R
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Gryczynski, I
Right arrow Articles by Lakowicz, J R

Resolution of end-to-end distance distributions of flexible molecules using quenching-induced variations of the Forster distance for fluorescence energy transfer.

I Gryczynski, W Wiczk, M L Johnson, H C Cheung, C K Wang and J R Lakowicz

University of Maryland, School of Medicine, Department of Biological Chemistry, Baltimore 21201.

ABSTRACT

We describe a new method to recover the distribution of donor-to-acceptor (D-A) distances in flexible molecules using steady-state measurements of the efficiency of fluorescence energy transfer. The method depends upon changes in the Forster distance (Ro) induced by collisional quenching of the donor emission. The Ro-dependent transfer efficiencies are analyzed using nonlinear least squares to recover the mean D-A distance and the width of the distribution. The method was developed and tested using three synthetic D-A pairs, in which the chromophores were separated by alkyl chains of varying lengths. As an example application we also recovered the distribution of distances from the single tryptophan residue in troponin I (trp 158) to acceptor-labeled cysteine 133. The half-width of the distribution increases from 12 A in the native state to 53 A when unfolded by guanidine hydrochloride. For both TnI and the three model compounds the distance distributions recovered from the steady-state transfer efficiencies were in excellent agreement with the distributions recovered using the more sophisticated frequency-domain method (Lakowicz, J.R., M.L. Johnson, W. Wiczk, A. Bhat, and R.F. Steiner. 1987. Chem. Phys. Lett. 138:587-593). The method was found to be reliable and should be generally useful for studies of conformational distributions of macromolecules.






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1988 by the Biophysical Society.