A novel antibody‐fluorescence method has been developed to elucidate the chromophore topography in phytochrome as it undergoes a photochromic transformation. Förster energy transfer from N‐terminal bound, fluorescently labeled Oat‐25 Fab antibody fragments to the phytochrome chromophore was measured. The results suggest that the chromophore moves relative to the N‐terminus upon the Pr → Pfr phototransformation. This conclusion is consistent with previous models which have proposed a reorientation and an interaction of the Pfr chromophore with the N‐terminus. The method described appears to be the first study of a Forster energy transfer measurement using a donor‐label attached to a Fab fragment of a photosensor protein.
|Original language||English (US)|
|Number of pages||9|
|Journal||Photochemistry and photobiology|
|State||Published - Nov 1992|
ASJC Scopus subject areas
- Physical and Theoretical Chemistry