Heterologe Expression von Apo-Phytochromen aus Solanum tuberosum und spektroskopische Charakterisierung der rekonstituierten Holo-Proteine

Abstract

Phytochrome B (phyB) from the potatoe solanum tuberosum in amounts sufficient for photochemical characterization with time-resolved absorption spectroscopy were obtained by expression in Saccharomyces cerevisiae and in Pichia pastoris. By reconstruction of the apophytochrome with two different chromophores, the chromophore - protein interaction could be studied. Analysis of the P_r#->#P_f_r reaction kinetics of phyB by means of flash photolysis resulted in the detection of four intermediates. From comparison with phyB deletion mutants and phyA (Avena) it is concluded that the N-terminus (amino acids 1-74) of phyB exhibits a strong influence on the position and form of the absorption bands of P_r and P_f_r. The c-terminus (amino acids 597-1133) of phyB is of no significance for the stable P_r and P_f_r form, but effects the reaction kinetics of the final P_f_r formation (I_x"i#->#P_f_r), which is accelerated by the absence of the c-terminus. (WEN)SIGLEAvailable from TIB Hannover: RN 9087(95)+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman