Effect of chromophore exchange on the resonance Raman spectra of recombinant phytochromes

FEBS Letters

Hildebrandt, P¹  Mozley, D¹  Gärtner, W¹  Kneip, C¹  Braslavsky, S.E¹  Schaffner, K¹ 

[1] Max-Planck-Institut für Strahlenchemie, Postfach 101365, D-45413 Mülheim, Germany

关键词: Phytochrome;    Tetrapyrrole;    Photoisomerization;    Resonance Raman;   

DOI  :  10.1016/S0014-5793(97)00969-1

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The recombinant 65-kDa polypeptide of phyA oat phytochrome was expressed by yeast Pichia pastoris and assembled into two chromopeptides with the chromophores phytochromobilin (PΦB) and phycocyanobilin (PCB), respectively. The P_r and P_fr states of the two protein variants were characterized by resonance Raman (RR) spectroscopy and compared with native phyA oat phytochrome demonstrating that the deletion of the C-terminal half of phyA does not alter the structure of the chromophore site within the N-terminal half. Most of the RR spectral changes observed upon replacing PΦB by PCB can be attributed exclusively to altered vibrational mode compositions due to the different ring D substitutions (vinyl vs. ethyl), implying that the chromophore structures are largely the same for PΦB- and PCB-assembled phytochromes. Only in the P_r state may the RR spectral changes also reflect subtle differences of the PΦB and PCB conformations in the 65-kDa phyA, presumably brought about by the specific steric requirements of the vinyl and ethyl groups.

【 授权许可】

Unknown