1d6p
From Proteopedia
(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...) |
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| - | [[Image:1d6p.gif|left|200px]]<br /><applet load="1d6p" size=" | + | [[Image:1d6p.gif|left|200px]]<br /><applet load="1d6p" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1d6p, resolution 2.23Å" /> | caption="1d6p, resolution 2.23Å" /> | ||
'''HUMAN LYSOZYME L63 MUTANT LABELLED WITH 2',3'-EPOXYPROPYL N,N'-DIACETYLCHITOBIOSE'''<br /> | '''HUMAN LYSOZYME L63 MUTANT LABELLED WITH 2',3'-EPOXYPROPYL N,N'-DIACETYLCHITOBIOSE'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The synergism between apolar and polar interactions in the carbohydrate | + | 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== | ==About this Structure== | ||
| - | 1D6P is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with GOL as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Lysozyme Lysozyme], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.17 3.2.1.17] Full crystallographic information is available from [http:// | + | 1D6P is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with <scene name='pdbligand=GOL:'>GOL</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Lysozyme Lysozyme], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.17 3.2.1.17] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1D6P OCA]. |
==Reference== | ==Reference== | ||
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[[Category: site-directed mutagenesis]] | [[Category: site-directed mutagenesis]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:13:34 2008'' |
Revision as of 10:13, 21 February 2008
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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 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
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