Horse liver alcohol dehydrogenase is a homodimeric protein; each subunit has two tryptophan residues that are in distinctly different microenvironments. Trp-15 is located on the surface and Trp-314 is buried at the intersubunit interface. Steady-state and time-resolved fluorescence and phosphorescence studies have enabled the assignment of parameters, e.g., quantum yield, emission maximum, decay times, to the individual tryptophan residues of the protein. We have prepared, by site-directed mutagenesis, the mutated W15F protein and have characterized its fluorescence properties. We show that the Trp-314 of the mutant experiences an apolar microenvironment, but that the fluorescence decay and exposure to solute quenchers of the mutant are somewhat different than was expected from the assignments for the wild type.

Date Published: 17 August 1994
PDF: 7 pages
Proc. SPIE 2137, Time-Resolved Laser Spectroscopy in Biochemistry IV, (17 August 1994); doi: 10.1117/12.182716

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