Titel der Dissertation:
Protonation and Conformational Dynamics of Phytochrome Variants and Fluorescent Phytochromes
Protonation and Conformational Dynamics of Phytochrome Variants and Fluorescent Phytochromes
Abstract: Phytochromes are red/far-red photosensor proteins found in many organisms, such as plants, bacteria or funghi. The investigated phytochromes are Cph1 from cyanobacteria, as well as Agp1 from the Agrobacterium tumefaciens.
The photosensor itself is a linear tetrapyrrole, which is bound to the photosensor module of phytochrome comprising the PAS, GAF and PHY domain (in short PGP) for Cph1, and Agp1. In this work the biophysical properties of four phytochrome were investigated to understand fluorescence enhancement in phytochrome-based near-infrared fluorescent proteins and to understand the contribution of the protonation heterogeneity to the function of phytochrome. Also the structural changes at various positions in Cph1 PGP and Agp1 PGP were measured as a function of pH using picosecond time-resolved fluorescence anisotropy. We showed that only in Cph1 PGP a direct correlation of chromophore deprotonation with pH-dependent conformational changes was found, but not in Agp1 PGP.
The photosensor itself is a linear tetrapyrrole, which is bound to the photosensor module of phytochrome comprising the PAS, GAF and PHY domain (in short PGP) for Cph1, and Agp1. In this work the biophysical properties of four phytochrome were investigated to understand fluorescence enhancement in phytochrome-based near-infrared fluorescent proteins and to understand the contribution of the protonation heterogeneity to the function of phytochrome. Also the structural changes at various positions in Cph1 PGP and Agp1 PGP were measured as a function of pH using picosecond time-resolved fluorescence anisotropy. We showed that only in Cph1 PGP a direct correlation of chromophore deprotonation with pH-dependent conformational changes was found, but not in Agp1 PGP.
Zeit & Ort
16.11.2022 | 16:30
Hörsaal A (1.3.14)
Fachbereich Physik, Arnimallee 14, 14195 Berlin