[Interpretation of 1H-NMR spectra of the cyclic analog of kallidin in solutions].
1H-NMR resonances of [cyclo (10-1 epsilon)]kallidin (cyclo-KL) in (CD3)2SO and H2O have been assigned by combined analysis of two-dimensional phase-sensitive COSY and NOESY spectra. The presence of three slowly interchangeable conformers cyclo-KL I, cyclo-KL II, and cyclo-KL III, has been established, their population in (CD3)2SO being 25, 35 and 40%, respectively. Cyclo-KL I conformer possesses trans-configuration of all peptide bonds, but in the cyclo-KL II and cyclo-KL III conformers the Pro3-Pro4 and Arg2-Pro3 peptide bonds, respectively, have cis-configuration. In----solution, the following exchange occurs between the conformers: cyclo-KL II----cyclo-KL I----cyclo-KL III. The assignment of 1H-NMR signals of all the three cyclo-KL conformers has been carried out in H2O by gradual titration with (CO3)2SO. The conformer populations in H2O are 45, 25 and 30%, respectively.
D000595:Amino Acid Sequence; D007609:Kallidin / Q000031:analogs & derivatives* / Q000032:analysis; D009682:Magnetic Resonance Spectroscopy; D010449:Peptide Mapping; D010456:Peptides, Cyclic / Q000032:analysis*; D011487:Protein Conformation; D012996:Solutions
D010456:Peptides, Cyclic; D012996:Solutions; D007609:Kallidin
Interpretatsiia spektrov 1H-IaMR tsiklicheskogo analoga kallidina v rastvorakh.