‘Mixed’ β-Peptides: A unique helical secondary structure in solution. Preliminary communication

✍ Scribed by Dieter Seebach; Karl Gademann; JüRg V. Schreiber; Jennifer L. Matthews; Tobias Hintermann; Bernhard Jaun; Lukas Oberer; Ulrich Hommel; Hans Widmer

• Book ID: 102256664
• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: German
• Weight: 393 KB
• Volume: 80
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.19970800703

✦ Synopsis

fi-Hexapeptides 1-5 and a 8-dodecapeptide 6 with sequences containing two different types of fi-amino acids (aliphatic proteinageous side chains in the 2-or in the 3-position) have been prepared. CD (Fig. f) and NMR measurements indicate that, with one exception, the secondary structures formed by these new 8-peptides differ from those of isomers studied previously. Detailed NMR analysis of the 8-hexapeptide 5 (with alternating fiZ,fi3-building blocks) and molecular-dynamics simulations have produced a minimum energy conformation (Fig. 2,b) which might be described as a novel irregular helix containing ten-and twelve-membered H-bonded rings. This demonstrates the great structural variability of fi-peptides, since three different helical secondary structures have been discovered to date.

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Part of the projected Ph. D. theses of K.G. and ZH., ETH-Zurich.