The analysis of the aromatic region of 1H and 13C NMR spectra of cyclolinopeptide A (cyclic nonapeptide with the sequence c—(Pro— Pro— Phe—Phe—Leu— Ile— Ile— Leu— Val— ), (CLA)) shows that Phe-3 and Phe-4 aromatic rings are oriented nearly perpendicularly to each other, forming edge-to-face pair. It signifies the strong limitation of the free rotation of aromatic residues, probably because of the steric hindrance exerted by proximal aliphatic side chains of CLA.
No takes yet. Share an insight, caveat, or question.
Ignacy Z. Siemion (1990) studied this question.
Synapse has enriched 5 related papers. Consider them for comparative context: