Distribution of distances in thiopeptides by fluorescence energy transfer and frequency-domain fluorometry.
Frequency-domain fluorescence spectroscopy was employed to examine the decays of tryptophan in Boc-Trp-Met-Asp-Phe-NH2 (donor) and (Formula: see text) (donor-acceptor pair). The efficiency of energy transfer in the thiopeptide amounted to 60%. The measured dispersion of fluorescence decay times was used to recover the donor-acceptor distance distribution. The parameters of the Gaussian distance distribution obtained for this peptide (r, the mean distance (9 A); hw, the halfwidth (25 A)) indicate the lack of a distinct favorable conformation.
Wiczk
W M
WM
University of Maryland, School of Medicine, Department of Biological Chemistry, Baltimore 21201.
Gryczynski
I
I
Szmacinski
H
H
Johnson
M L
ML
Kruszynski
M
M
Zboinska
J
J
D004735:Energy Transfer; D010418:Pentagastrin / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D011487:Protein Conformation; D013050:Spectrometry, Fluorescence / Q000379:methods; D013438:Sulfhydryl Compounds / Q000138:chemical synthesis; D014364:Tryptophan
D013438:Sulfhydryl Compounds; C041024:tertiary-butyloxycarbonyl-glycyl-tryptophyl-methionyl-aspartyl-phenylalaninamide; D014364:Tryptophan; D010418:Pentagastrin