1ngl
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(New page: 200px<br /> <applet load="1ngl" size="450" color="white" frame="true" align="right" spinBox="true" caption="1ngl" /> '''HUMAN NEUTROPHIL GELATINASE-ASSOCIATED LIPO...)
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Revision as of 16:15, 12 November 2007
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HUMAN NEUTROPHIL GELATINASE-ASSOCIATED LIPOCALIN (HNGAL), REGULARISED AVERAGE NMR STRUCTURE
Overview
Human neutrophil gelatinase-associated lipocalin (HNGAL) is a member of, the lipocalin family of extracellular proteins that function as, transporters of small, hydrophobic molecules. HNGAL, a component of human, blood granulocytes, binds bacterially derived formyl peptides that act as, chemotactic agents and induce leukocyte granule discharge. HNGAL also, forms a complex with the proenzyme form of matrix metalloproteinase-9, (pro-MMP-9, or progelatinase B) via an intermolecular disulphide bridge., This association allows the subsequent formation of ternary and quaternary, metalloproteinase/inhibitor complexes that vary greatly in their, metalloproteinase activities. The structure and dynamics of apo-HNGAL have, been determined by NMR spectroscopy. Simulated annealing calculations, yielded a set of 20 convergent structures with an average backbone RMSD, from mean coordinate positions of 0. 79(+/-0.13) A over secondary, structure elements. The overall rotational correlation time (13.3 ns), derived from15N relaxation data is consistent with a monomeric protein of, the size of HNGAL (179 residues) under the experimental conditions (1.4 mM, protein, pH 6.0, 24.5 degrees C). The structure features an eight-stranded, antiparallel beta-barrel, typical of the lipocalin family. One end of the, barrel is open, providing access to the binding site within the barrel, cavity, while the other is closed by a short 310-helix. The free cysteine, residue required for association with pro-MMP-9 lies in an inter-strand, loop at the closed end of the barrel. The structure provides a detailed, model of the ligand-binding site and has led to the proposal of a site for, pro-MMP-9 association. Dynamic data correlate well with structural, features, which has allowed us to investigate a mechanism by which a, cell-surface receptor might distinguish between apo and holo-HNGAL through, conformational changes at the open end of the barrel.
About this Structure
1NGL is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
The solution structure and dynamics of human neutrophil gelatinase-associated lipocalin., Coles M, Diercks T, Muehlenweg B, Bartsch S, Zolzer V, Tschesche H, Kessler H, J Mol Biol. 1999 May 28;289(1):139-57. PMID:10339412
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