208l: Difference between revisions
New page: left|200px<br /><applet load="208l" size="450" color="white" frame="true" align="right" spinBox="true" caption="208l, resolution 2.2Å" /> '''MUTANT HUMAN LYSOZYME... |
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[[Image:208l.jpg|left|200px]]<br /><applet load="208l" size=" | [[Image:208l.jpg|left|200px]]<br /><applet load="208l" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="208l, resolution 2.2Å" /> | caption="208l, resolution 2.2Å" /> | ||
'''MUTANT HUMAN LYSOZYME C77A'''<br /> | '''MUTANT HUMAN LYSOZYME C77A'''<br /> | ||
==Overview== | ==Overview== | ||
We previously reported that protein disulfide isomerase (PDI) can | We previously reported that protein disulfide isomerase (PDI) can dissociate the glutathione molecule in vitro from the mutant human lysozyme (hLZM) C77A-a, which is modified with glutathione at Cys95; however, it seems structurally difficult for PDI to attack either the disulfide bond or the side chain of the cysteine residue of a mixed disulfide. To investigate the function of PDI, we introduced several glutathione and cysteine derivatives at Cys95, instead of the glutathione of C77A-a. Using thiol compounds modified by 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB), we could easily modify the free thiol group of C77A-b (C77A with no glutathionylation), without denaturation. For all of the modifications we tested, a negative correlation was found between the initial rate and the acceleration ratio of the reductive cleavage of mixed disulfides with PDI. A mutant PDI (hPDIM), which has no thiol-disulfide exchange activity, suppressed the reductive cleavage of the mixed disulfide of C77A-a with hPDI, suggesting that hPDI non-covalently interacted with the substrates. Taking account of the results of the structural analysis, we conclude that one of the functions of PDI in vivo lies in relaxing the structure around the disulfide bond, as well as in exchanging the thiol-disulfide bonds. | ||
==About this Structure== | ==About this Structure== | ||
208L 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 CYS 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:// | 208L 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=CYS:'>CYS</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=208L OCA]. | ||
==Reference== | ==Reference== | ||
A role of PDI in the reductive cleavage of mixed disulfides., Nakamura S, Matsushima M, Song H, Kikuchi M, J Biochem | A role of PDI in the reductive cleavage of mixed disulfides., Nakamura S, Matsushima M, Song H, Kikuchi M, J Biochem. 1996 Sep;120(3):525-30. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=8902616 8902616] | ||
[[Category: Homo sapiens]] | [[Category: Homo sapiens]] | ||
[[Category: Lysozyme]] | [[Category: Lysozyme]] | ||
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[[Category: mutant human lysozyme]] | [[Category: mutant human lysozyme]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:20:57 2008'' | ||
Revision as of 17:21, 21 February 2008
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MUTANT HUMAN LYSOZYME C77A
OverviewOverview
We previously reported that protein disulfide isomerase (PDI) can dissociate the glutathione molecule in vitro from the mutant human lysozyme (hLZM) C77A-a, which is modified with glutathione at Cys95; however, it seems structurally difficult for PDI to attack either the disulfide bond or the side chain of the cysteine residue of a mixed disulfide. To investigate the function of PDI, we introduced several glutathione and cysteine derivatives at Cys95, instead of the glutathione of C77A-a. Using thiol compounds modified by 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB), we could easily modify the free thiol group of C77A-b (C77A with no glutathionylation), without denaturation. For all of the modifications we tested, a negative correlation was found between the initial rate and the acceleration ratio of the reductive cleavage of mixed disulfides with PDI. A mutant PDI (hPDIM), which has no thiol-disulfide exchange activity, suppressed the reductive cleavage of the mixed disulfide of C77A-a with hPDI, suggesting that hPDI non-covalently interacted with the substrates. Taking account of the results of the structural analysis, we conclude that one of the functions of PDI in vivo lies in relaxing the structure around the disulfide bond, as well as in exchanging the thiol-disulfide bonds.
About this StructureAbout this Structure
208L 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.
ReferenceReference
A role of PDI in the reductive cleavage of mixed disulfides., Nakamura S, Matsushima M, Song H, Kikuchi M, J Biochem. 1996 Sep;120(3):525-30. PMID:8902616
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