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

Authors

  • Dieter Seebach,

    Corresponding author
    1. Laboratorium für Organische Chemie der Eidgenössischen Technischen Hochschule, ETH-Zentrum, Universitätstrasse 16, CH-8092 Zürich
    • Laboratorium für Organische Chemie der Eidgenössischen Technischen Hochschule, ETH-Zentrum, Universitätstrasse 16, CH-8092 Zürich

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  • Karl Gademann,

    1. Laboratorium für Organische Chemie der Eidgenössischen Technischen Hochschule, ETH-Zentrum, Universitätstrasse 16, CH-8092 Zürich
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    • Part of the projected Ph. D. theses of K.G. and T.H., ETH-Zürich.

  • JüRg V. Schreiber,

    1. Laboratorium für Organische Chemie der Eidgenössischen Technischen Hochschule, ETH-Zentrum, Universitätstrasse 16, CH-8092 Zürich
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    • Part of the Master's thesis of J.V.S., ETH-Zürich, 1997.

  • Jennifer L. Matthews,

    1. Laboratorium für Organische Chemie der Eidgenössischen Technischen Hochschule, ETH-Zentrum, Universitätstrasse 16, CH-8092 Zürich
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    • Royal Society (UK) Postdoctoral Research Fellow 1995–1996; Swiss National Science Foundation Fellowship Holder 1996–1997 (grant No.21-40659.94).

  • Tobias Hintermann,

    1. Laboratorium für Organische Chemie der Eidgenössischen Technischen Hochschule, ETH-Zentrum, Universitätstrasse 16, CH-8092 Zürich
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    • Part of the projected Ph. D. theses of K.G. and T.H., ETH-Zürich.

  • Bernhard Jaun,

    1. Laboratorium für Organische Chemie der Eidgenössischen Technischen Hochschule, ETH-Zentrum, Universitätstrasse 16, CH-8092 Zürich
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  • Lukas Oberer,

    1. Präklinische Forschung, Novartis Pharma AG, Research Core Technology Area, CH-4002 Basel
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  • Ulrich Hommel,

    1. Präklinische Forschung, Novartis Pharma AG, Research Core Technology Area, CH-4002 Basel
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  • Hans Widmer

    1. Präklinische Forschung, Novartis Pharma AG, Research Core Technology Area, CH-4002 Basel
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Abstract

β-Hexapeptides 1–5 and a β-dodecapeptide 6 with sequences containing two different types of β-amino acids (aliphatic proteinageous side chains in the 2- or in the 3-position) have been prepared. CD (Fig. 1) and NMR measurements indicate that, with one exception, the secondary structures formed by these new β-peptides differ from those of isomers studied previously. Detailed NMR analysis of the β-hexapeptide 5 (with alternating β23-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 β-peptides, since three different helical secondary structures have been discovered to date.

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