A proton NMR investigation of proline-24 cis-trans isomerism in corticotropin 1-32 and related peptides.
250 MHz 1H-NMR studies performed on aqueous solutions of corticotropin1-32, corticotropin1-24, corticotropin15-32, corticotropin20-32 and corticotropin15-24 have allowed the location and the subsequent assignment of the signals of Tyrosine-23 aromatic protons and valine-22 methyl protons. These signals are sensitive to the geometry of proline-24, clearly transcribe its isomerism and yield the ratio of the cis-trans conformers. It is concluded that for large peptides in specific cases, the proton signals of side chains can be used to probe the backbone conformation.
D000324:Adrenocorticotropic Hormone; D006863:Hydrogen-Ion Concentration; D007536:Isomerism; D009682:Magnetic Resonance Spectroscopy; D008970:Molecular Weight; D010446:Peptide Fragments; D011392:Proline; D013329:Structure-Activity Relationship
D010446:Peptide Fragments; D000324:Adrenocorticotropic Hormone; D011392:Proline