2ffr
From Proteopedia
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Crystallographic studies on N-azido-beta-D-glucopyranosylamine, an inhibitor of glycogen phosphorylase: comparison with N-acetyl-beta-D-glucopyranosylamine
Overview
N-acetyl-beta-D-glucopyranosylamine (NAG) is a potent inhibitor (Ki=32, microM) of glycogen phosphorylase b (GPb), and has been employed as a lead, compound for the structure-based design of new analogues, in an effort to, utilize its potential as a hypoglycaemic agent. Replacement of the, acetamido group by azidoacetamido group resulted in an inhibitor, N-azidoacetyl-beta-D-glucopyranosylamine (azido-NAG), with a Ki value of, 48.7 microM, in the direction of glycogen synthesis. In order to elucidate, the mechanism of inhibition, we determined the ligand structure in complex, with GPb at 2.03 A resolution, and the structure of the fully acetylated, derivative in the free form. The molecular packing of the latter is, stabilized by a number of bifurcated hydrogen bonds of which the one, involving a bifurcated C-H...N...H-C type hydrogen bonding is rather, unique in organic azides. Azido-NAG can be accommodated in the catalytic, site of T-state GPb at approximately the same position as that of NAG and, stabilizes the T-state conformation of the 280 s loop by making several, favourable contacts to residues of this loop. The difference observed in, the Ki values of the two analogues can be interpreted in terms of, desolvation effects, subtle structural changes of protein residues and, changes in water structure.
About this Structure
2FFR is a Single protein structure of sequence from Oryctolagus cuniculus with PLP and DL6 as ligands. Active as Phosphorylase, with EC number 2.4.1.1 Full crystallographic information is available from OCA.
Reference
Crystallographic studies on N-azidoacetyl-beta-D-glucopyranosylamine, an inhibitor of glycogen phosphorylase: comparison with N-acetyl-beta-D-glucopyranosylamine., Petsalakis EI, Chrysina ED, Tiraidis C, Hadjiloi T, Leonidas DD, Oikonomakos NG, Aich U, Varghese B, Loganathan D, Bioorg Med Chem. 2006 Aug 1;14(15):5316-24. Epub 2006 Apr 17. PMID:16616506
Page seeded by OCA on Wed Nov 21 10:32:10 2007
