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| - | [[Image:2ih9.gif|left|200px]] | + | {{Seed}} |
| | + | [[Image:2ih9.png|left|200px]] |
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| | {{STRUCTURE_2ih9| PDB=2ih9 | SCENE= }} | | {{STRUCTURE_2ih9| PDB=2ih9 | SCENE= }} |
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| - | '''A high-dose crystal structure of a recombinant Melanocarbus albomyces laccase'''
| + | ===A high-dose crystal structure of a recombinant Melanocarbus albomyces laccase=== |
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| - | ==Overview==
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| - | Laccases (p-diphenol dioxygen oxidoreductases) belong to the family of blue multicopper oxidases, which catalyse the four-electron reduction of dioxygen to water concomitantly through the oxidation of substrate molecules. Blue multicopper oxidases have four coppers, a copper (T1) forming a mononuclear site and a cluster of three coppers (T2, T3, and T3') forming a trinuclear site. Because X-rays are known to liberate electrons during data collection and may thus affect the oxidation state of metals, we have investigated the effect of X-ray radiation upon the crystal structure of a recombinant laccase from Melanocarpus albomyces through the use of crystallography and crystal absorption spectroscopy. Two data sets with different strategies, a low and a high-dose data set, were collected at synchrotron. We have observed earlier that the trinuclear site had an elongated electron density amidst coppers, suggesting dioxygen binding. The low-dose synchrotron structure showed similar elongated electron density, but the high-dose X-ray radiation removed the bulk of this density. Therefore, X-ray radiation could alter the active site of laccase from M. albomyces. Absorption spectra of the crystals (320, 420, and 590nm) during X-ray radiation were measured at a home laboratory. Spectra clearly showed how that the band at 590nm had vanished, resulting from the T1 copper being reduced, during the long X-ray measurements. The crystal colour changed from blue to colourless. Absorptions at 320 and 420nm seemed to be rather permanent. The absorption at 320nm is due to the T3 coppers and it is proposed that absorption at 420nm is due to the T2 copper when dioxygen or a reaction intermediate is close to this copper.
| + | The line below this paragraph, {{ABSTRACT_PUBMED_17045575}}, adds the Publication Abstract to the page |
| | + | (as it appears on PubMed at http://www.pubmed.gov), where 17045575 is the PubMed ID number. |
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| | + | {{ABSTRACT_PUBMED_17045575}} |
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| | ==About this Structure== | | ==About this Structure== |
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| | [[Category: Multicopper oxidase]] | | [[Category: Multicopper oxidase]] |
| | [[Category: Redox enzyme]] | | [[Category: Redox enzyme]] |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun May 4 07:30:06 2008'' | + | |
| | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Jul 27 22:37:30 2008'' |
Revision as of 19:37, 27 July 2008
Template:STRUCTURE 2ih9
A high-dose crystal structure of a recombinant Melanocarbus albomyces laccase
Template:ABSTRACT PUBMED 17045575
About this Structure
2IH9 is a Single protein structure of sequence from Melanocarpus albomyces. Full crystallographic information is available from OCA.
Reference
A crystallographic and spectroscopic study on the effect of X-ray radiation on the crystal structure of Melanocarpus albomyces laccase., Hakulinen N, Kruus K, Koivula A, Rouvinen J, Biochem Biophys Res Commun. 2006 Dec 1;350(4):929-34. Epub 2006 Oct 5. PMID:17045575
Page seeded by OCA on Sun Jul 27 22:37:30 2008
