The-effect of capper(II) ions on the probabilities of existence of the four detectable conformers of the tetrapeptide Tyr-Pro-Phe-Pro (beta -casomorphin 4) in [H-2(6)]DMSO was investigated by H-1 NMR Spectroscopy. Integration of the Phe-NH signals provided the relative populations in the free state as tt/tc/ct/cc = 28.34.29:9 at 293 K (c = cis, t = trans). Copper(ii) was shown to bind to all four isomers, yielding complexes with two different structures, depending on the conformation of Pro(2). The interpretation of paramagnetic relaxation rates of Pro(2)-H alpha signals provided the corresponding isomeric probabilities in the metal-bound state as 13:36:20:31. The observed stabilization of the conformation with the lowest probability of-existence (cc) may be relevant for the biological role of copper and other metal ions.

Gaggelli, E., N., D., Gaggelli, N., & Valensin, G. (2001). Metal ion effects on cis/trans isomerization of proline residues in short chain peptides in solution. CHEMBIOCHEM, 2, 524-529 [10.1002/1439-7633(20010803)2:7/8<524::AID-CBIC524>3.0.CO;2-P].

Metal ion effects on cis/trans isomerization of proline residues in short chain peptides in solution

GAGGELLI, ELENA;GAGGELLI, NICOLA;VALENSIN, GIANNI
2001

Abstract

The-effect of capper(II) ions on the probabilities of existence of the four detectable conformers of the tetrapeptide Tyr-Pro-Phe-Pro (beta -casomorphin 4) in [H-2(6)]DMSO was investigated by H-1 NMR Spectroscopy. Integration of the Phe-NH signals provided the relative populations in the free state as tt/tc/ct/cc = 28.34.29:9 at 293 K (c = cis, t = trans). Copper(ii) was shown to bind to all four isomers, yielding complexes with two different structures, depending on the conformation of Pro(2). The interpretation of paramagnetic relaxation rates of Pro(2)-H alpha signals provided the corresponding isomeric probabilities in the metal-bound state as 13:36:20:31. The observed stabilization of the conformation with the lowest probability of-existence (cc) may be relevant for the biological role of copper and other metal ions.
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11365/27861
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