Ananda, Kuppanna and Vasudev, Prema G and Sengupta, Anindita and Poopathi Raja, K Muruga and Shamala, Narayanaswamy and Balaram, Padmanabhan (2005) Polypeptide Helices in Hybrid Peptide Sequences. In: Journal of the American Chemical Society, 127 (47). pp. 16668-16674.
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A new class of polypeptide helices in hybrid sequences containing alpha-, beta-, and gamma-residues is described. The molecular conformations in crystals determined for the synthetic peptides Boc-Leu-Phe-Val-Aib-beta Phe-Leu-Phe-Val-OMe 1 (beta Phe: (S)-beta(3)-homophenylalanine) and Boc-Aib-Gpn-AibGpn-OM2(Gpn:1-(aminomethyl)cycl hexaneacetic acid) reveal expanded helical turns in the hybrid sequences (alpha alpha beta)(n) and (ay), In 1, a repetitive helical structure composed Of C-14 hydrogen-bonded units is observed, whereas 2 provides an example of a repetitive C-12 hydrogen-bonded structure. Using experimentally determined backbone torsion angles for the hydrogen-bonded units formed by hybrid sequences, we have generated energetically favorable hybrid helices. Conformational parameters are provided for C-11, C-12, C-13, C-14, and C-15 helices in hybrid sequences.
|Item Type:||Journal Article|
|Additional Information:||Copy right of this article belongs to American Chemical Society.|
|Department/Centre:||Division of Biological Sciences > Molecular Biophysics Unit|
|Date Deposited:||30 Apr 2010 04:53|
|Last Modified:||19 Sep 2010 06:01|
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