English
 
Help Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Journal Article

Properties of site-specifically incorporated 3-Aminotyrosine in proteins to study redox-active tyrosines: E. coli ribonucleotide reductase as a paradigm.

MPS-Authors
/persons/resource/persons189558

Kasanmascheff,  M.
Research Group of Electron Paramagnetic Resonance, MPI for biophysical chemistry, Max Planck Society;

/persons/resource/persons14834

Bennati,  M.
Research Group of Electron Paramagnetic Resonance, MPI for biophysical chemistry, Max Planck Society;

External Resource
No external resources are shared
Fulltext (restricted access)
There are currently no full texts shared for your IP range.
Fulltext (public)
There are no public fulltexts stored in PuRe
Supplementary Material (public)

2574187_Suppl.pdf
(Supplementary material), 3MB

Citation

Lee, W., Kasanmascheff, M., Huynh, M., Quartartaro, A., Constentin, C., Bejenke, I., et al. (2018). Properties of site-specifically incorporated 3-Aminotyrosine in proteins to study redox-active tyrosines: E. coli ribonucleotide reductase as a paradigm. Biochemistry, 57(24), 3402-3415. doi:10.1021/acs.biochem.8b00160.


Cite as: https://hdl.handle.net/21.11116/0000-0001-1C2E-E
Abstract
3-Aminotyrosine (NH2Y) has been a useful probe to study the role of redox active tyrosines in enzymes. This report describes properties of NH2Y of key importance for its application in mechanistic studies. By combining the tRNA/NH2Y-RS suppression technology with a model protein tailored for amino acid redox studies (α3X, X = NH2Y), the formal reduction potential of NH2Y32(O•/OH) (E°’ = 395 ± 7 mV at pH 7.08 ± 0.05) could be determined using protein film voltammetry. We find that the ΔE°’ between NH2Y32(O•/OH) and Y32(O•/OH) when measured under reversible conditions is ~300 – 400 mV larger than earlier estimates based on irreversible voltammograms obtained on aqueous NH2Y and Y. We have also generated D6-NH2Y731-α2 of RNR, which when incubated with β2/CDP/ATP generates the D6-NH2Y731•-α2/β2 complex. By multi-frequency EPR (35, 94 and 263 GHz) and 34 GHz 1H ENDOR spectroscopies, we determined the hyperfine coupling (hfc) constants of the amino protons that establishes RNH2• planarity and thus minimal perturbation of the reduction potential by the protein environment. The amount of Y in the isolated NH2Y-RNR incorporated by infidelity of the tRNA/NH2Y-RS pair was determined by a generally useful LC-MS method. This information is essential to the utility of this NH2Y probe to study any protein of interest and is employed to address our previously reported activity associated with NH2Y-substituted RNRs