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Article: Single-Molecule Spectroscopy Selectively Probes Donor and Acceptor Chromophores in the Phycobiliprotein Allophycocyanin
- Article from:
- Biophysical Journal
- Article date:
- October 1, 2004
- Author:
CopyrightCopyright Biophysical Society Oct 2004. Provided by ProQuest LLC. (Hide copyright information)
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ABSTRACT
We report on single-molecule fluorescence measurements performed on the phycobiliprotein allophycocyanin (APC). Our data support the presence of a unidirectional Förster-type energy transfer process involving spectrally different chromophores, α84 (donor) and β84 (acceptor), as well as of energy hopping amongst β84 chromophores. Single-molecule fluorescence spectra recorded from individual immobilized APC proteins indicate the presence of a red-emitting chromophore with emission peaking at 660 nm, which we connect with β84, and a species with the emission peak blue shifted at 630 nm, which we attribute to α84. Polarization data from single APC trimers ...