This Article Full Text Full Text (PDF) Supplement All Versions of this Article: biophysj.106.092650v1 92/12/4168    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by VanBeek, D. B. Articles by Krueger, B. P. Search for Related Content PubMed PubMed Citation Articles by VanBeek, D. B. Articles by Krueger, B. P.

Fretting about FRET: Correlation between and R

Hope College, Department of Chemistry, Holland, Michigan

Correspondence: Address reprint requests to B. P. Krueger, Tel.: 616-395-7629; E-mail: kruegerb{at}hope.edu.

Molecular dynamics simulations were used to examine the structural dynamics of two fluorescent probes attached to a typical protein, hen egg-white lysozyme (HEWL). The donor probe (D) was attached via a succinimide group, consistent with the commonly-used maleimide conjugation chemistry, and the acceptor probe (A) was bound into the protein as occurs naturally for HEWL and the dye Eosin Y. The ² is found to deviate significantly from the theoretical value and high correlation between the orientation factor and the distance R is observed. The correlation is quantified using several possible fixed A orientations and correlation as high as 0.80 is found between and R and as high as 0.68 between ² and R. The presence of this correlation highlights the fact that essentially all fluorescence-detected resonance energy transfer studies have assumed that and R are independent—an assumption that is clearly not justified in the system studied here. The correlation results in the quantities ²R^–6 and ² R^–6 differing by a factor of 1.6. The observed correlation between and R is caused by the succinimide linkage between the D and HEWL, which is found to be relatively inflexible.

This article has been cited by other articles:

				A. Iqbal, S. Arslan, B. Okumus, T. J. Wilson, G. Giraud, D. G. Norman, T. Ha, and D. M. J. Lilley Orientation dependence in fluorescent energy transfer between Cy3 and Cy5 terminally attached to double-stranded nucleic acids PNAS, August 12, 2008; 105(32): 11176 - 11181. [Abstract] [Full Text] [PDF]

				H. Wang, S. Mao, J. M. Chalovich, and G. Marriott Tropomyosin Dynamics in Cardiac Thin Filaments: A Multisite Forster Resonance Energy Transfer and Anisotropy Study Biophys. J., June 1, 2008; 94(11): 4358 - 4369. [Abstract] [Full Text] [PDF]