1hd9: Difference between revisions
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==Overview== | ==Overview== | ||
We have determined the NMR structure in aqueous solution of a, disulphide-cyclised 11-residue peptide that forms a stable beta-hairpin, incorporating a type VIb beta-turn. The structure is found to be extremely, well ordered for a short peptide, with the 30 lowest energy simulated, annealing structures having an average pairwise r.m.s. deviation of only, 0.36 A over the backbone. All but three side-chains adopt distinct, conformations, allowing a detailed analysis of their involvement in, cross-strand interactions. The peptide sequence analysed originates from a, previously reported study, which identified potent inhibitors of human, leukocyte elastase from screening a combinatorial peptide library based on, the short protein beta-sheet segment that forms the reactive site loop of, ... | We have determined the NMR structure in aqueous solution of a, disulphide-cyclised 11-residue peptide that forms a stable beta-hairpin, incorporating a type VIb beta-turn. The structure is found to be extremely, well ordered for a short peptide, with the 30 lowest energy simulated, annealing structures having an average pairwise r.m.s. deviation of only, 0.36 A over the backbone. All but three side-chains adopt distinct, conformations, allowing a detailed analysis of their involvement in, cross-strand interactions. The peptide sequence analysed originates from a, previously reported study, which identified potent inhibitors of human, leukocyte elastase from screening a combinatorial peptide library based on, the short protein beta-sheet segment that forms the reactive site loop of, Bowman-Birk inhibitors. A detailed comparison of the peptide's solution, structure with the corresponding region in the whole protein structure, reveals a very good correspondence not only for the backbone (r.m.s., deviation approximately 0.7 A) but also for the side-chains. This isolated, beta-hairpin retains the biologically active "canonical conformation", typical of small serine proteinase inhibitor proteins, which explains why, it retains inhibitory activity. Since the structural integrity is, sequence-inherent and does not depend upon the presence of the remaining, protein, this beta-hairpin represents an independent structural motif and, so provides a useful model of this type of protein architecture and its, relation to biological function. The relationship between the conformation, of this beta-hairpin and its biological activity is discussed. | ||
==About this Structure== | ==About this Structure== | ||
1HD9 is a | 1HD9 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/ ]. Structure known Active Site: P1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1HD9 OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: type vib beta-turn peptide]] | [[Category: type vib beta-turn peptide]] | ||
''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 5 15:10:15 2007'' | ||
