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Updated: Aug 17, 2026

Nuclear Magnetic Resonance Spectroscopy for the Identification of Multiple Phosphorylations of Intrinsically Disordered Proteins
Published on: December 27, 2016
Photo-CIDNP NMR spectroscopy of a heme-containing protein
Iain J Day1, Rachel Wain, Kaeko Tozawa
1Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, UK.
Abstract:
There are relatively few examples of the application of photo-CIDNP NMR spectroscopy to chromophore-containing proteins. The most likely reason for this is that simultaneous absorption of light by the photosensitiser molecule and the protein chromophore reduces the effectiveness of the photochemical reaction that produces the observed nuclear polarisation. We present details of experiments performed on the air-oxidised form of a small cytochrome, from the thermophilic bacterium Hydrogenobacter thermophilus, using both the wild-type protein and apo and holo forms of a double alanine b-type mutant. We show that, along with the apo state, it is possible to generate CIDNP in the air-oxidised form of the b-type mutant, but not in the corresponding c-type cytochrome. This finding is supported by control experiments using horse-heart cytochrome c.
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