โ Scribed by J.C. White; Lubert Stryer
No coin nor oath required. For personal study only.
Photostability studies of four fluorescent phycobiliproteins were conducted to identify stable chromophores for biological labeling applications. Phycobiliprotein photodestruction was linear with the applied laser power and depended on the total number of photons absorbed per molecule. Photodestruction quantum yields &I of 1.1 X 10m5 for R-phycoerythrin, 6.6 X 10m6 for B-phycoerythrin, 4.5 X 10m6 for allophycocyanin, and 2.5 X 10m6 for C-phycocyanin were measured. C-Phycocyanin is a factor of 10.8 more photostable than fluorescein. The photostability of R-phycoerythrin was improved by a factor of 1.7 by adding n-propyl gallate. The addition of superoxide dismutase, catalase, sodium dithionite, ascorbate. dithiothreitol, EDTA. or deoxygenation with argon bubbling had no effect on the photostability of R-phycoerythrin.
๐ SIMILAR VOLUMES
Three 7-aminocoumarin derivatives, 7-carboxymethylamino-4-trifluoromethyl-2H-1-benzopyran-2-one [2], 7-carboxymethylamino-4-methyl-2H-1-benzopyrank2-one [4], and 7-dimethylamino-4-formyl-2H-1-benzopyran-2-one [6], were prepared. The reagents can be attached to primary amino groups of proteins. The l