1 May 1990 Transient effects in the solute quenching of tryptophan residues in proteins
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Abstract
Fluorescence quenching reactions, using such quenchers as oxygen and acrylamide, have been used to obtain information about the kinetic exposure of tryptophan residues in proteins. Often, both dynamic and static quenching components can be observed. The transient term of the Smoluchowski equation has been shown by Lakowicz et al (J. Biol. Chem. 10907-10910 (1987)) to be needed to fit acrylamide and oxygen quenching lifetime data with proteins. Here we show that this transient term can also explain the apparent static quenching that can be observed in some cases. By numerical integration of an impulse-response function, which includes a transient solute quenching term, we have simultaneously fitted intensity and phase lifetime Stern-Volmer plots for the oxygen and acrylamide quenching of selected single tryptophan proteins. These fits require a single fitting parameter, the diffusion of the quencher. Using this fitting procedure we have reinvestigated the effect of bulk viscosity on the acrylamide quenching of the fluorescence of the buried tryptophan in ribonuclease T1. We show that for this protein the intensity and lifetime data sets can be better fitted by a two-step diffusion model.
© (1990) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Maurice R. Eftink, Maurice R. Eftink, } "Transient effects in the solute quenching of tryptophan residues in proteins", Proc. SPIE 1204, Time-Resolved Laser Spectroscopy in Biochemistry II, (1 May 1990); doi: 10.1117/12.17705; https://doi.org/10.1117/12.17705
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