Copper(II)-catalyzed amide isomerization: Evidence for N-coordination

Journal of the American Chemical Society

Volumn 118, Issue 22, 1996, Pages 5332-5333

  Cox, Christopher ^a   Ferraris, Dana ^a   Murthy, Narasimha N ^a   Lectka, Thomas ^a  

^a JOHNS HOPKINS UNIVERSITY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

AMIDE; COPPER;

ARTICLE; BINDING SITE; CATALYSIS; ISOMERISM; PROTEIN FOLDING; PROTON NUCLEAR MAGNETIC RESONANCE; STOICHIOMETRY; X RAY CRYSTALLOGRAPHY;

EID: 0030008366     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja960693c     Document Type: Article

References (27)

1. Schmid, F. X. In Protein Folding; Creighton, T. E., Ed.; W. H. Freeman: New York, 1992; pp 197-241.
2. For two overviews, see: (a) Schmid, F. X.; Mayr, L. M.; Mücke, M.; Schönbrunner, E. R. Adv. Protein Chem. 1993, 44, 25. (b) Schreiber, S. L. Science 1991, 251, 283.
3. For two overviews, see: (a) Schmid, F. X.; Mayr, L. M.; Mücke, M.; Schönbrunner, E. R. Adv. Protein Chem. 1993, 44, 25. (b) Schreiber, S. L. Science 1991, 251, 283.
4. Kördel, J.; Drakenberg, T; Forsen, S.; Thulin, E. FEBS Lett. 1990, 263, 27.
5. a denotes the amide nitrogen.
6. Fussenegger, R.; Rode, B. M. Chem. Phys. Lett. 1976, 44, 95.
7. Waghorne, W. E.; Ward, A. J. I.; Clune, T. G.; Cox, B. G. J. Chem. Soc., Faraday Trans. 1 1980, 76, 1131.
8. Other transition metals were screened, including Ag(I), Ni(II), and Zn(II), but Cu(II) was found to be the most effective.
9. a-coordination involving undeprotonated amides in peptides has been observed in a crystal structure of a Cu(II) - urea complex (Maslak, P.; Sczepanski, J. J.; Parvez, M. J. Am. Chem. Soc. 1991, 113, 1062) and in an Ir(II)-8-amidoquinoline complex (Lee, J. C.; Müller; Pregosin, P.; Yap, G. P. A.; Rheingold, A. L.; Crabtree, R. H. Inorg. Chem. 1995, 34, 6295).
10. a-coordination involving undeprotonated amides in peptides has been observed in a crystal structure of a Cu(II) - urea complex (Maslak, P.; Sczepanski, J. J.; Parvez, M. J. Am. Chem. Soc. 1991, 113, 1062) and in an Ir(II)-8-amidoquinoline complex (Lee, J. C.; Müller; Pregosin, P.; Yap, G. P. A.; Rheingold, A. L.; Crabtree, R. H. Inorg. Chem. 1995, 34, 6295).
11. All new compounds were synthesized by standard literature methods and gave satisfactory analyses (IR, NMR, MS, elemental).
12. Forsén, S.; Hoffman, R. A. Acta Chem. Scand. 1963, 17, 1787. For a review of the theory of saturation transfer, see: Sanders, J. K. M.; Mersh, J. D. Prog. Nucl. Magn. Reson. Spectrosc. 1983, 15, 353. For development and applications to rotation of amides, see: Perrin, C. L.; Thoburn, J. D.; Kresge, J. J. Am. Chem. Soc. 1992, 114, 8800. Details of our experimental protocol are given in the supporting information.
13. Forsén, S.; Hoffman, R. A. Acta Chem. Scand. 1963, 17, 1787. For a review of the theory of saturation transfer, see: Sanders, J. K. M.; Mersh, J. D. Prog. Nucl. Magn. Reson. Spectrosc. 1983, 15, 353. For development and applications to rotation of amides, see: Perrin, C. L.; Thoburn, J. D.; Kresge, J. J. Am. Chem. Soc. 1992, 114, 8800. Details of our experimental protocol are given in the supporting information.
14. Forsén, S.; Hoffman, R. A. Acta Chem. Scand. 1963, 17, 1787. For a review of the theory of saturation transfer, see: Sanders, J. K. M.; Mersh, J. D. Prog. Nucl. Magn. Reson. Spectrosc. 1983, 15, 353. For development and applications to rotation of amides, see: Perrin, C. L.; Thoburn, J. D.; Kresge, J. J. Am. Chem. Soc. 1992, 114, 8800. Details of our experimental protocol are given in the supporting information.
15. The methylene protons of 1a - 1c and 1e were sampled in quadruplicate runs. The quantities of Cu(II) catalyst employed were limited by paramagnetic broadening at high concentrations. With some exceptions, generally a range of 4 - 10 mol % Cu(II) gave the best balance of catalysis and reproducibility.
16. 6) is negligible for free amides 1.
17. 19F to our knowledge.
18. Basosi, R.; Antholine, W. E.; Hyde, J. S. In Biological Magnetic Resonance; Berliner, L. J., Reuben, J., Eds.; Plenum Press: New York, 1993; pp 103-150.
19. 1/a.
20. Johnson, F. Chem. Rev. 1968, 68, 375.
21. A crystal structure of t-Boc-Pro-Pro-OH reveals psuedoaxially disposed, endo α-substituents: Thomas, L. M.; Ramasubbu, N.; Bhandary, K. K. Int. J. Pep. Protein Res. 1994, 44, 207.
22. At the metal concentrations screened, there was no perturbation of the cisltrans equilibrium constants for the substituted prolines, consistent with Cu(II)'S role as a true catalyst.
23. Proton NOE data for proline 3b are indicative of an endo carbonyl, whereas for 3a ab initio calculations (3-21G basis) indicate that an exo carbonyl is the favored conformation, which may account for the greater barrier lowering in 3b.
24. In contrast, no catalysis was observed in the rotation of the side chain amido group of 3c, a fact consistent with our model.
25. Steinberg, I. Z; Harrington, W. F.; Berger, A.; Sela, M.; Katchalski, E. J. Am. Chem. Soc. 1960, 82, 5263. Torchia, D. A.; Bovey, F. A. Macromolecules 1971, 4, 246.
26. Steinberg, I. Z; Harrington, W. F.; Berger, A.; Sela, M.; Katchalski, E. J. Am. Chem. Soc. 1960, 82, 5263. Torchia, D. A.; Bovey, F. A. Macromolecules 1971, 4, 246.
27. Steinmann, B.; Bruckner, P.; Supertifurga, A. J. Biol. Chem. 1991, 266, 1299.