Premium
STABILIZATION OF PHYTOCHROME INTERMEDIATES BY LOW TEMPERATURE *
Author(s) -
Pratt L. H.,
Butler W. L.
Publication year - 1968
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.1968.tb05891.x
Subject(s) - phytochrome , absorbance , phosphate buffered saline , absorption (acoustics) , extinction (optical mineralogy) , glycerol , photochemistry , irradiation , chemistry , molar absorptivity , red light , biophysics , botany , chromatography , biology , biochemistry , optics , physics , mineralogy , nuclear physics
— The photocon versions between the red‐absorbing form (P r ) and the far‐red absorbing form ( P fr ) of phytochrome were examined at low temperatures. Partially purified preparations of the chromoprotein were examined in phosphate buffer and in 25 per cent buffer plus 75 per cent glycerol. Actinic irradiation of P , below – 150°C produces an intermediate with maximum absorbance near 695 nm, R 695 . Actinic irradiation of R 695 converts it back to P . Above – 150°C R 695 decays to a low extinction form of phytochrome, R , which in turn decays to P fr upon further warming. Light absorption by P fr below – 150°C results in the formation of an intermediate form of phytochrome with maximum absorbance near 660 nm, FR 660 . FR 660 decays upon warming to a lower extinction form, FR' . which in turn decays to P r on continued warming. No evidence was obtained to suggest that any of the observed intermediate states are involved in more than one direction of phytochrome photocon version.