Structural Dimorphism of Achiral α,γ-Hybrid Peptide Foldamers: Coexistence of 12- and 15/17-Helices.
| Autor: | Misra R; Department of Chemistry, Indian Institution of Science Education and Research, Dr. Homi Bhabha Road, Pune, 411021, India., Saseendran A; Department of Chemistry, Indian Institution of Science Education and Research, Dr. Homi Bhabha Road, Pune, 411021, India., George G; NMR Research Center, Indian Institute of Science, Bangalore, 560012, India., Veeresh K; Department of Chemistry, Indian Institution of Science Education and Research, Dr. Homi Bhabha Road, Pune, 411021, India., Raja KM; Department of Physical Chemistry, School of Chemistry, Madurai Kamaraj University, Madurai, 625 021, India., Raghothama S; NMR Research Center, Indian Institute of Science, Bangalore, 560012, India., Hofmann HJ; Institute of Biochemistry, Faculty of Biosciences, Pharmacy and Psychology, Talstraße 33, 04103, Leipzig, Germany., Gopi HN; Department of Chemistry, Indian Institution of Science Education and Research, Dr. Homi Bhabha Road, Pune, 411021, India. |
|---|---|
| Jazyk: | angličtina |
| Zdroj: | Chemistry (Weinheim an der Bergstrasse, Germany) [Chemistry] 2017 Mar 13; Vol. 23 (15), pp. 3764-3772. Date of Electronic Publication: 2017 Feb 14. |
| DOI: | 10.1002/chem.201605753 |
| Abstrakt: | Here, novel 12-helices in α,γ-hybrid peptides composed of achiral α-aminoisobutyric acid (Aib) and 4-aminoisocaproic acid (Aic, doubly homologated Aib) monomers in 1:1 alternation are reported. The 12-helices were indicated by solution and crystal structural analyses of tetra- and heptapeptides. Surprisingly, single crystals of the longer nonapeptide displayed two different helix types: the novel 12-helix and an unprecedented 15/17-helix. Quantum chemical calculations on both helix types in a series of continuously lengthened Aib/Aic-hybrid peptides confirm that the 12-helix is more stable than the 15/17-helix in shorter peptides, whereas the 15/17-helix is more stable in longer sequences. Thus, the coexistence of both helix types can be expected within a definite range of sequence lengths. The novel 15/17- and 12-helices in α,γ-hybrid peptides with 5→1 and 4→1 hydrogen-bonding patterns, respectively, can be viewed as backbone-expanded analogues of native α- and 3 (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.) |
| Databáze: | MEDLINE |
| Externí odkaz: |
|