7SPV

Crystal structure of photoactive yellow protein (PYP); F92oCNF construct

Summary for 7SPV

• Entry DOI: 10.2210/pdb7spv/pdb
• Descriptor: Photoactive yellow protein, 4'-HYDROXYCINNAMIC ACID (3 entities in total)
• Functional Keywords: photoreceptor, signaling protein
• Biological source: Halorhodospira halophila (Ectothiorhodospira halophila)
• Total number of polymer chains: 1
• Total formula weight: 14077.74

Authors

Weaver, J.B.,Kirsh, J.M.,Boxer, S.G. (deposition date: 2021-11-03, release date: 2022-05-11, Last modification date: 2023-11-15)

Primary citation

Weaver, J.B.,Kozuch, J.,Kirsh, J.M.,Boxer, S.G.
Nitrile Infrared Intensities Characterize Electric Fields and Hydrogen Bonding in Protic, Aprotic, and Protein Environments.
J.Am.Chem.Soc., 144:7562-7567, 2022

PubMed Abstract: Nitriles are widely used vibrational probes; however, the interpretation of their IR frequencies is complicated by hydrogen bonding (H-bonding) in protic environments. We report a new vibrational Stark effect (VSE) that correlates the electric field projected on the -C≡N bond to the transition dipole moment and, by extension, the nitrile peak area or integrated intensity. This linear VSE applies to H-bonding and non-H-bonding interactions. It can therefore be generally applied to determine electric fields in all environments. Additionally, it allows for semiempirical extraction of the H-bonding contribution to the blueshift of the nitrile frequency. Nitriles were incorporated at H-bonding and non-H-bonding protein sites using amber suppression, and each nitrile variant was structurally characterized at high resolution. We exploited the combined information available from variations in frequency and integrated intensity and demonstrate that nitriles are a generally useful probe for electric fields.

PubMed: 35467853
DOI: 10.1021/jacs.2c00675

Experimental method

X-RAY DIFFRACTION (1.18 Å)