Abstract
High-resolution 1H NMR spectra at 300 MHz of the polypeptide cardiac stimulants anthopIeurin-A and Anemonia sulcata toxin II reveal conformational heterogeneity in both molecules. The two conformations, manifest in a number of split 1H resonances, are in slow exchange over a wide range of pH and temperature. Heterogeneity affects a region of these molecules containing the structurally and functionally important Asp residues. By comparison with a homologous polypeptide Anemonia sulcata toxin I, which does not show this type of heterogeneity, it is suggested that the heterogeneity may originate in cis-trans isomerism of the Gly-40 to Pro-41 peptide bond.
Original language | English |
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Pages (from-to) | 15-19 |
Number of pages | 5 |
Journal | FEBS Letters |
Volume | 174 |
Issue number | 1 |
DOIs | |
Publication status | Published - 20 Aug 1984 |
Externally published | Yes |
Keywords
- H-NMR
- Cardiotonic agent
- Neurotoxin
- Peptide conformation
- pH titration
- Proline