Premium
Dynamic Nuclear Polarization Provides New Insights into Chromophore Structure in Phytochrome Photoreceptors
Author(s) -
Stöppler Daniel,
Song Chen,
van Rossum BarthJan,
Geiger MichelAndreas,
Lang Christina,
Mroginski MariaAndrea,
Jagtap Anil Pandurang,
Sigurdsson Snorri Th.,
Matysik Jörg,
Hughes Jon,
Oschkinat Hartmut
Publication year - 2016
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201608119
Subject(s) - phytochrome , phycocyanobilin , chromophore , photoisomerization , chemistry , photochromism , magic angle spinning , protonation , isomerization , biophysics , nuclear magnetic resonance spectroscopy , photochemistry , stereochemistry , red light , biology , biochemistry , organic chemistry , ion , cyanobacteria , botany , genetics , phycocyanin , bacteria , catalysis
Phytochromes are red/far‐red photochromic photoreceptors acting as master regulators of development in higher plants, thereby controlling transcription of about 20 % of their genes. Light‐induced isomerization of the bilin chromophore leads to large rearrangements in protein structure, whereby the role of protonation dynamics and charge distribution is of particular interest. To help unravel the inherent mechanisms, we present two‐dimensional dynamic nuclear polarization (DNP) enhanced solid‐state magic‐angle spinning (MAS) NMR spectra of the functional sensory module of the cyanobacterial phytochrome Cph1. To this end, the pyrrole ring nitrogen signals were assigned unequivocally, enabling us to locate the positive charge of the phycocyanobilin (PCB) chromophore. To help analyze proton exchange pathways, the proximity of PCB ring nitrogen atoms and functionally relevant H 2 O molecules was also determined. Our study demonstrates the value of DNP in biological solid‐state MAS NMR spectroscopy.