2onb
From Proteopedia
(New page: 200px<br /><applet load="2onb" size="450" color="white" frame="true" align="right" spinBox="true" caption="2onb, resolution 2.700Å" /> '''Human Thymidylate S...) |
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| - | [[Image:2onb.gif|left|200px]]<br /><applet load="2onb" size=" | + | [[Image:2onb.gif|left|200px]]<br /><applet load="2onb" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="2onb, resolution 2.700Å" /> | caption="2onb, resolution 2.700Å" /> | ||
'''Human Thymidylate Synthase at low salt conditions with PDPA bound'''<br /> | '''Human Thymidylate Synthase at low salt conditions with PDPA bound'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Thymidylate synthase (TS) is a target in the chemotherapy of colorectal | + | Thymidylate synthase (TS) is a target in the chemotherapy of colorectal cancer and some other neoplasms. It catalyzes the transfer of a methyl group from methylenetetrahydrofolate to dUMP to form dTMP. On the basis of structural considerations, we have introduced 1,3-propanediphosphonic acid (PDPA) as an allosteric inhibitor of human TS (hTS); it is proposed that PDPA acts by stabilizing an inactive conformer of loop 181-197. Kinetic studies showed that PDPA is a mixed (noncompetitive) inhibitor versus dUMP. In contrast, versus methylenetrahydrofolate at concentrations lower than 0.25 microM, PDPA is an uncompetitive inhibitor, while at PDPA concentrations higher than 1 microM the inhibiton is noncompetive, as expected. At the concentrations corresponding to uncompetitive inhibition, PDPA shows positive cooperativity with an antifolate inhibitor, ZD9331, which binds to the active conformer. PDPA binding leads to the formation of hTS tetramers, but not higher oligomers. These data are consistent with a model in which hTS exists preferably as an asymmetric dimer with one subunit in the active conformation of loop 181-197 and the other in the inactive conformation. |
==About this Structure== | ==About this Structure== | ||
| - | 2ONB 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 SO4, EDO and 7PA as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 2ONB 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=SO4:'>SO4</scene>, <scene name='pdbligand=EDO:'>EDO</scene> and <scene name='pdbligand=7PA:'>7PA</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2ONB OCA]. |
==Reference== | ==Reference== | ||
| - | Cooperative inhibition of human thymidylate synthase by mixtures of active site binding and allosteric inhibitors | + | Cooperative inhibition of human thymidylate synthase by mixtures of active site binding and allosteric inhibitors., Lovelace LL, Gibson LM, Lebioda L, Biochemistry. 2007 Mar 13;46(10):2823-30. Epub 2007 Feb 13. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17297914 17297914] |
[[Category: Homo sapiens]] | [[Category: Homo sapiens]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Gibson, L | + | [[Category: Gibson, L M.]] |
[[Category: Lebioda, L.]] | [[Category: Lebioda, L.]] | ||
| - | [[Category: Lovelace, L | + | [[Category: Lovelace, L L.]] |
[[Category: 7PA]] | [[Category: 7PA]] | ||
[[Category: EDO]] | [[Category: EDO]] | ||
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[[Category: zd9331]] | [[Category: zd9331]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 18:20:22 2008'' |
Revision as of 16:20, 21 February 2008
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Human Thymidylate Synthase at low salt conditions with PDPA bound
Overview
Thymidylate synthase (TS) is a target in the chemotherapy of colorectal cancer and some other neoplasms. It catalyzes the transfer of a methyl group from methylenetetrahydrofolate to dUMP to form dTMP. On the basis of structural considerations, we have introduced 1,3-propanediphosphonic acid (PDPA) as an allosteric inhibitor of human TS (hTS); it is proposed that PDPA acts by stabilizing an inactive conformer of loop 181-197. Kinetic studies showed that PDPA is a mixed (noncompetitive) inhibitor versus dUMP. In contrast, versus methylenetrahydrofolate at concentrations lower than 0.25 microM, PDPA is an uncompetitive inhibitor, while at PDPA concentrations higher than 1 microM the inhibiton is noncompetive, as expected. At the concentrations corresponding to uncompetitive inhibition, PDPA shows positive cooperativity with an antifolate inhibitor, ZD9331, which binds to the active conformer. PDPA binding leads to the formation of hTS tetramers, but not higher oligomers. These data are consistent with a model in which hTS exists preferably as an asymmetric dimer with one subunit in the active conformation of loop 181-197 and the other in the inactive conformation.
About this Structure
2ONB is a Single protein structure of sequence from Homo sapiens with , and as ligands. Full crystallographic information is available from OCA.
Reference
Cooperative inhibition of human thymidylate synthase by mixtures of active site binding and allosteric inhibitors., Lovelace LL, Gibson LM, Lebioda L, Biochemistry. 2007 Mar 13;46(10):2823-30. Epub 2007 Feb 13. PMID:17297914
Page seeded by OCA on Thu Feb 21 18:20:22 2008
Categories: Homo sapiens | Single protein | Gibson, L M. | Lebioda, L. | Lovelace, L L. | 7PA | EDO | SO4 | Diphosphonic acid | Fdump | Heteroinhibition | Zd9331
