Share Email Print
cover

Proceedings Paper

Time-resolved fluorescence of the two tryptophans in transducin a(greek)-subunit
Author(s): Yefim Manevich; Scott Williams; Charles M. Phillips; P. A. Liebman
Format Member Price Non-Member Price
PDF $14.40 $18.00

Paper Abstract

Ga contains two tryptophans. Tryptophan fluorescence decay of Ga at 25°C in 10 mM Tris-HC1 buffer pH=7.3 was triexponential with lifetimes of 3.62, 1.06 and 0.l7ns. Contrary to expectation, the shorter lived (lower quantum yield) components were blue-shifted relative to the longer Denaturation with 8M urea diminished the 1.O6ns component and increased net intensity which became dominated by a lifetime of 5. iOns. Emission of a tryptophan species was identified at 450nm with lifetime of 20-4Ons, similar to that reported earlier by Vanderkooi J. et al' . This long-wavelength emission was also eliminated by 8M urea denaturation, making it seem possible that the low intensity of the 1 .O6ns blue shifted component may result from competing excited state processes that give rise to the 450nm emission. Transient absorbance spectra of Ga show no evidence for triplet states in denatured protein while the native protein showed phosphorescence at 442nm of lifetime between 0. 1 and 1 .Oms.

Paper Details

Date Published: 17 August 1994
PDF: 6 pages
Proc. SPIE 2137, Time-Resolved Laser Spectroscopy in Biochemistry IV, (17 August 1994); doi: 10.1117/12.182722
Show Author Affiliations
Yefim Manevich, Univ. of Pennsylvania Medical Ctr. (United States)
Scott Williams, Univ. of Pennsylvania (United States)
Charles M. Phillips, Univ. of Pennsylvania (United States)
P. A. Liebman, Univ. of Pennsylvania Medical Ctr. (United States)


Published in SPIE Proceedings Vol. 2137:
Time-Resolved Laser Spectroscopy in Biochemistry IV
Joseph R. Lakowicz, Editor(s)

© SPIE. Terms of Use
Back to Top