The design and NMR structure determination of yttrium-oligopeptide tags for recombinant proteins and antibodies
Marcela Múdra, Martin Breza *, Lucia Lintnerová a, Juraj Filo b, Jacob Bauer c
Faculty of Chemical and Food Technology, Slovak University of Technology,
Radlinského 9, SK-812 37 Bratislava, Slovakia
a Department of Chemical Theory of Drugs, Faculty of Pharmacy, Comenius University,
Odbojárov 10, SK-832 32 Bratislava, Slovakia
b Institute of Chemistry, Faculty of Natural Sciences, Comenius University,
Mlynská dolina CH-2, SK-842 15 Bratislava, Slovakia
c Institute of Molecular Biology, Slovak Academy of Sciences,
Dúbravská cesta 21, SK-845 51 Bratislava, Slovakia
E-mail: * martin.breza@stuba.sk
Abstract: A strategy for the design of new yttrium(III) tags consisting of sequences of naturally occurring amino acids is described. These tags are 4—6 amino acids in length and consist of aspartic and glutamic acids. The use of natural amino acids would allow these oligopeptides to be incorporated into recombinant proteins at the DNA level, enabling the protein to be Y(III)-labelled after protein isolation. This allows a radionuclide or heavy atom to be associated with the protein without the necessity of further synthetic modification. Suitable peptides able to chelate Y(III) in stable complexes were designed based on quantum-chemical calculations. The stability of complexes formed by these peptides was tested by isothermal titration calorimetry, giving dissociation constants in the micromolar range. The likely structure of the most tightly bound complex was inferred from a combination of NMR experiments and quantum-chemical calculations. This structure will serve as the basis for future optimizations.
Keywords: carboxylate ligands; density functional calculations; NMR spectroscopy; peptide design; yttrium tags
Full paper in Portable Document Format: acs_0309.pdf
Acta Chimica Slovaca, Vol. 11, No. 2, 2018, pp. 120—133, DOI: 10.2478/acs-2018-0018