Fluorinated amino acids for probing direct contacts by <sup>19</sup>F-NMR — ASN Events
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  2. SESSION 8: Innovations in peptide science
  3. Fluorinated amino acids for probing direct contacts by 19F-NMR

Fluorinated amino acids for probing direct contacts by 19F-NMR (#38)

Gottfried Otting 1 , Yi Jiun Tan 1 , Kasuni Ekanayake 1 , Elwy Abdelkader Ali 1 , Haocheng Qianzhu 1 , Thomas Huber 1
  1. Research School of Chemistry, Australian National University, Canberra, Australia

Non-canonical amino acids can be incorporated into proteins in response to an amber stop codon, using suitable aminoacyl-tRNA synthetases that are orthogonal to native E. coli systems. Using this approach, we can replace a single H atom in a protein by an F atom. Fluorinated amino acids are of particular interest, as the fluorine atoms can be selectively and sensitively detected by 19F-NMR. They can be regarded as site-specific spys that report on changes in their chemical environment. Furthermore, through-space scalar couplings between fluorine atoms can be detected, if they form direct contacts. This is possible even if the contacts are transient. Applications are demonstrated for proteins exchanging between open and closed conformations, and for protein systems > 60 kDa.

 

 

  1. K. B. Ekanayake, M. C. Mahawaththa, H. Qianzhu, E. H. Abdelkader, J. George, S. Ullrich, R. B. Murphy, S. E. Fry, J. Johansen-Leete, R. J. Payne, C. Nitsche, T. Huber, G. Otting Probing ligand binding sites on large proteins by NMR spectroscopy of genetically encoded non-canonical amino acids J. Med. Chem. 66, 5289-5304 (2023)
  2. H. Qianzhu, E. H. Abdelkader, I. D. Herath, G. Otting, T. Huber Site-specific incorporation of 7-fluoro-L-tryptophan into proteins by genetic encoding to monitor ligand binding by 19F NMR spectroscopy ACS Sens. 7, 44-48 (2022)
  3. H. W. Orton, H. Qianzhu, E. H. Abdelkader, Y. J. Tan, E. I. Habel, R. L. Frkic, C. J. Jackson, T. Huber, G. Otting Through-space scalar 19F-19F couplings between fluorinated non-canonical amino acids for the detection of specific contacts in proteins J. Am. Chem. Soc., 143, 19587-19598 (2021)
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