Abstract
The structure and conformation of the cyclodipeptide, cyclo(Tyrosyl-Prolyl), cyclo(Tyr-Pro) have been investigated with X-ray crystallographic and spectroscopic methods. Two conformations of cyclo(Tyr-Pro) crystallized in the space groupP21212 with cell dimensionsa=11.890(3),b=12.057(1),c=18.528(4). Both these conformations are uncommon for cyclodipeptides containing a proline residue. The tyrosyl side chains of these conformers are folded towards the diketopiperazine (DKP) ring. The DKP ring adopts a flattened chair conformation in contrast to the typical boat conformation generally observed for DKP rings. The conformation of the pyrrolidine ring can be described as a pseudo C2 symmetrical twist. One intermolecular hydrogen bond was observed for each of the two conformations of cyclo(Tyr-Pro). The hydrogen of the hydroxyl group of the tyrosyl residue is hydrogen bonded to the oxygen of the carbonyl group of the diketopiperazine ring, i.e., the carbonyl group originating from the tyrosyl residue. NMR spectroscopic studies indicated a different conformation for cyclo(Tyr-Pro) in solution similar to the generally observed conformation of cyclodipeptides, i.e., extended aromatic side chain and boat conformation for the DKP ring.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Bystrov, V. F. (1976)Progr. NMR Spectr. 10, 41–81.
Ciarkowski, J., Gdaniec, M., Kolodziejczyk, A., Liberek, B., Borremans, F. A. M., and Anteunis, M. J. O. (1990)Int. J. Peptide Protein Res. 36, 285–291.
Deber, C. M., Madison, V., and Blout, E. R. (1976)Acc. Chem. Res. 9, 106–113.
Gdaniec, M. (1981)Pol. J. Chem. 55, 1795–1802.
Gdaniec, M., Liberek, B., Kolodziejczyk, A. S., Jankowska, R., and Ciarkowski, J. (1987).Int. J. Pep. Prot. Res. 30, 79–92.
Haasnoot, C. A. G., De Leeuw, F. A. A. M., De Leeuw, H. P. M., and Altona, C. (1981)Biopolymers 20, 1211–1245.
Jankowska, R., and Ciarkowski, J. (1987)Int. J. Pep. Prot. Res. 30, 61–78.
Milne, P. J., Oliver, D. W., and Roos, H. M. (1992) Crystal structure of the dihydrate. To be published elsewhere.
Madison, V., Young, P. E., and Blout, E. R. (1976)J. Am. Chem. Soc. 98, 5358–5364.
Mazza, F., Lucente, G., Pinnen, F., and Zanotti, G. (1984)Acta Crystallogr. C 40, 1974–1976.
Pachler, K. G. R. (1964)Spectrochim. Acta. 20, 581–587.
Sammes, P. G. (1975)Forts. Chem. Organ. Naturst. 32, 51–118.
Sheldrick, G. M. (1976)SHELX76. Program for crystal structure determination (University of Cambridge, England).
Siemion, I. Z. (1976)Org. Magn. Res. 8, 432–435.
Szafranek, J., Palacz, Z., and Grzonka, S. (1976)Org. Mass. Spectr. 11, 920–930.
Toniolo, C. (1990)Int. J. Pep. Prot. Res. 35, 287–300.
Young, P. E., Madison, V., and Blout, E. R. (1976)J. Am. Chem. Soc. 98, 5365–5371.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Milne, P.J., Oliver, D.W. & Roos, H.M. Cyclodipeptides: Structure and conformation of cyclo(tyrosyl-prolyl). Journal of Crystallographic and Spectroscopic Research 22, 643–649 (1992). https://doi.org/10.1007/BF01160980
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF01160980