1d6p
From Proteopedia
OCA (Talk | contribs)
(New page: 200px<br /><applet load="1d6p" size="450" color="white" frame="true" align="right" spinBox="true" caption="1d6p, resolution 2.23Å" /> '''HUMAN LYSOZYME L63 M...)
Next diff →
Revision as of 10:55, 20 November 2007
|
HUMAN LYSOZYME L63 MUTANT LABELLED WITH 2',3'-EPOXYPROPYL N,N'-DIACETYLCHITOBIOSE
Overview
The synergism between apolar and polar interactions in the carbohydrate, recognition by human lysozyme (HL) was probed by site-directed mutagenesis, and affinity labeling. The three-dimensional structures of the Tyr63-->Leu, mutant HL labeled with 2',3'-epoxypropyl beta-glycoside of, N,N'-diacetylchitobiose (L63-HL/NAG-NAG-EPO complex) and the Asp102-->Glu, mutant HL labeled with the 2',3'-epoxypropyl beta-glycoside of, N-acetyllactosamine were revealed by X-ray diffraction at 2.23 and 1.96 A, resolution, respectively. Compared to the wild-type HL labeled with the, 2', 3'-epoxypropyl beta-glycoside of N,N'-diacetylchitobiose, the, N-acetylglucosamine residue at subsite B of the L63-HL/NAG-NAG-EPO complex, markedly moved away from the 63rd residue, with substantial loss of, hydrogen-bonding interactions. Evidently, the stacking interaction with, the aromatic side chain of Tyr63 is essential in positioning the, N-acetylglucosamine residue in the productive binding mode. On the other, hand, the position of the galactose residue in subsite B of HL is almost, unchanged by the mutation of Asp102 to Glu. Most hydrogen bonds, including, the one between the carboxylate group of Glu102 and the axial 4-OH group, of the galactose residue, were maintained by local movement of the, backbone from residues 102-104. In both structures, the conformation of, the disaccharide was conserved, reflecting an intrinsic conformational, rigidity of the disaccharides. The structural analysis suggested that, CH-pi interactions played an important role in the recognition of the, carbohydrate residue at subsite B of HL.
About this Structure
1D6P is a Single protein structure of sequence from Homo sapiens with GOL as ligand. Active as Lysozyme, with EC number 3.2.1.17 Full crystallographic information is available from OCA.
Reference
Protein-carbohydrate interactions in human lysozyme probed by combining site-directed mutagenesis and affinity labeling., Muraki M, Harata K, Sugita N, Sato KI, Biochemistry. 2000 Jan 18;39(2):292-9. PMID:10630988
Page seeded by OCA on Tue Nov 20 13:03:07 2007
