The distance between the phytochrome chromophore and the N-terminal chain decreases during phototransformation. A novel fluorescence energy transfer method using labeled antibody fragments.
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 Förster energy transfer measurement using a donor-label attached to a Fab fragment of a photosensor protein.
Farrens
D L
DL
Department of Chemistry, University of Nebraska, Lincoln 68588-0304.
Cordonnier
M M
MM
Pratt
L H
LH
Song
P S
PS
D004735:Energy Transfer; D005455:Fluorescent Antibody Technique; D008027:Light; D010777:Photochemistry; D010834:Phytochrome / Q000737:chemistry* / Q000528:radiation effects; D010944:Plants / Q000737:chemistry / Q000528:radiation effects
D010834:Phytochrome