2cbd: Difference between revisions
New page: left|200px<br /> <applet load="2cbd" size="450" color="white" frame="true" align="right" spinBox="true" caption="2cbd, resolution 1.67Å" /> '''STRUCTURE OF NATIVE... |
No edit summary |
||
| Line 1: | Line 1: | ||
[[Image:2cbd. | [[Image:2cbd.jpg|left|200px]]<br /><applet load="2cbd" size="350" color="white" frame="true" align="right" spinBox="true" | ||
<applet load="2cbd" size=" | |||
caption="2cbd, resolution 1.67Å" /> | caption="2cbd, resolution 1.67Å" /> | ||
'''STRUCTURE OF NATIVE AND APO CARBONIC ANHYDRASE II AND SOME OF ITS ANION-LIGAND COMPLEXES'''<br /> | '''STRUCTURE OF NATIVE AND APO CARBONIC ANHYDRASE II AND SOME OF ITS ANION-LIGAND COMPLEXES'''<br /> | ||
| Line 11: | Line 10: | ||
==About this Structure== | ==About this Structure== | ||
2CBD 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 ZN and SO3 as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Carbonate_dehydratase Carbonate dehydratase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.2.1.1 4.2.1.1] Full crystallographic information is available from [http:// | 2CBD 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=ZN:'>ZN</scene> and <scene name='pdbligand=SO3:'>SO3</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Carbonate_dehydratase Carbonate dehydratase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.2.1.1 4.2.1.1] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2CBD OCA]. | ||
==Reference== | ==Reference== | ||
| Line 26: | Line 25: | ||
[[Category: lyase(oxo-acid)]] | [[Category: lyase(oxo-acid)]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri Feb 15 17:18:00 2008'' | ||
Revision as of 18:18, 15 February 2008
|
STRUCTURE OF NATIVE AND APO CARBONIC ANHYDRASE II AND SOME OF ITS ANION-LIGAND COMPLEXES
OverviewOverview
In order to obtain a better structural framework for understanding the, catalytic mechanism of carbonic anhydrase, a number of inhibitor complexes, of the enzyme were investigated crystallographically. The, three-dimensional structure of free human carbonic anhydrase II was, refined at pH 7.8 (1.54 A resolution) and at pH 6.0 (1.67 A resolution)., The structure around the zinc ion was identical at both pH values. The, structure of the zinc-free enzyme was virtually identical with that of the, native enzyme, apart from a water molecule that had moved 0.9 A to fill, the space that would be occupied by the zinc ion. The complexes with the, anionic inhibitors bisulfite and formate were also studied at neutral pH., Bisulfite binds with one of its oxygen atoms, presumably protonized, to, the zinc ion and replaces the zinc water. Formate, lacking a hydroxyl, group, is bound with its oxygen atoms not far away from the position of, the non-protonized oxygen atoms of the bisulfite complex, i.e. at hydrogen, bond distance from Thr199 N and at a position between the zinc ion and the, hydrophobic part of the active site. The result of these and other studies, have implications for our view of the catalytic function of the enzyme, since virtually all inhibitors share some features with substrate, product, or expected transition states. A reaction scheme where electrophilic, activation of carbon dioxide plays an important role in the hydration, reaction is presented. In the reverse direction, the protonized oxygen of, the bicarbonate is forced upon the zinc ion, thereby facilitating cleavage, of the carbon-oxygen bond. This is achieved by the combined action of the, anionic binding site, which binds carboxyl groups, the side-chain of, threonine 199, which discriminates between hydrogen bond donors and, acceptors, and hydrophobic interaction between substrate and the active, site cavity. The required proton transfer between the zinc water and His64, can take place through water molecules 292 and 318.
DiseaseDisease
Known disease associated with this structure: Osteopetrosis, autosomal recessive 3, with renal tubular acidosis OMIM:[611492]
About this StructureAbout this Structure
2CBD is a Single protein structure of sequence from Homo sapiens with and as ligands. Active as Carbonate dehydratase, with EC number 4.2.1.1 Full crystallographic information is available from OCA.
ReferenceReference
Structure of native and apo carbonic anhydrase II and structure of some of its anion-ligand complexes., Hakansson K, Carlsson M, Svensson LA, Liljas A, J Mol Biol. 1992 Oct 20;227(4):1192-204. PMID:1433293
Page seeded by OCA on Fri Feb 15 17:18:00 2008