Campus Units

Chemistry

Document Type

Article

Publication Version

Published Version

Publication Date

1-1995

Journal or Book Title

Journal of the American Chemical Society

Volume

117

Issue

2

First Page

733

Last Page

739

DOI

10.1021/ja00107a016

Abstract

The utility of 7-azatryptophan as an alternative to tryptophan for optically probing protein structure and dynamics is demonstrated by investigating the complex of egg-white avidin and biotinylated 7-azatryptophan. We report the synthesis of biotinylated 7-azatryptophan and optical measurements of its complex with avidin. Although there are four biotin binding sites, the emission from the 7-azatryptophan tagged to biotin decays by a single exponential, whereas the tryptophyl emission from avidin requires two exponentials in order to be adequately fit. Fluorescence depolarization measurements of the complex probed by emission from 7-azatryptophan reveal both rapid (-80 ps) and much longer-lived decay. The former component is attributable to the local motion of the probe with respect to the protein; the latter component represents overall protein tumbling. In addition, energy transfer from tryptophan to 7-azatryptophan and a blue-shift in the spectrum of biotinylated 7-azatryptophan are observed upon formation of the complex. Modified strategies of effecting optical selectivity are also discussed.

Comments

Reprinted (adapted) with permission from Journal of the American Chemical Society 117 (1995): 733, doi: 10.1021/ja00107a016. Copyright 1995 American Chemical Society.

Copyright Owner

American Chemical Society

Language

en

File Format

application/pdf

Included in

Chemistry Commons

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