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Proceedings Paper • Open Access

Phycobiliprotein fusion proteins: versatile intensely fluorescent constructs
Author(s): Alexander N. Glazer; Yuping A. Cai; Aaron J. Tooley

Paper Abstract

Since 1982, phycobiliproteins have served as fluorescent labels in a wide variety of cell and molecule analyses. The exceptional spectroscopic properties of these labels include very high absorbance coefficients and quantum yields, and large Stokes shifts. The spectroscopic diversity of these reagents is restricted to a subset of naturally occurring phycobiliproteins with stable assembly states in vitro, whose target specificity is generated by chemical conjugation to proteins or small molecules. The latter step generates heterogeneity. These limitations have been overcome by expressing various recombinant phycobiliprotein constructs in the cyanobacterium Anabaena sp. PCC7120. Modular recombinant phycobiliprotein-based labels were constructed with some or all of the following features (a) an affinity purification tag; (b) a stable oligomerization domain (to maintain stable higher order assemblies of the phycobiliprotein monomers at very low protein concentration); (c) a biospecific recognition domain. Such phycobiliprotein constructs are readily purified from crude cell extracts by affinity chromatography and used directly as fluorescent labels. To generate constructs for intracellular in vivo labeling, the entire pathways for the biosynthesis of the His-tagged holo- α (phycocyanobilin-bearing) subunit of phycocyanin (emission max. 641 nm) and of the His-tagged holo-α (phycobiliviolin-bearing) subunit of phycoerythrocyanin (emission max. 582 nm) were reconstituted in Escherichia coli.

Paper Details

Date Published: 14 June 2004
PDF: 3 pages
Proc. SPIE 5329, Genetically Engineered and Optical Probes for Biomedical Applications II, (14 June 2004); doi: 10.1117/12.527786
Show Author Affiliations
Alexander N. Glazer, Univ. of California/Berkeley (United States)
Yuping A. Cai, Eli Lilly & Co. (United States)
Aaron J. Tooley, Univ. of California/San Francisco (United States)

Published in SPIE Proceedings Vol. 5329:
Genetically Engineered and Optical Probes for Biomedical Applications II
Alexander P. Savitsky; Darryl J. Bornhop; Ramesh Raghavachari; Samuel I. Achilefu, Editor(s)

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