1m8r: Difference between revisions
New page: left|200px<br /><applet load="1m8r" size="450" color="white" frame="true" align="right" spinBox="true" caption="1m8r, resolution 1.90Å" /> '''Crystal Structures o... |
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[[Image:1m8r.jpg|left|200px]]<br /><applet load="1m8r" size=" | [[Image:1m8r.jpg|left|200px]]<br /><applet load="1m8r" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="1m8r, resolution 1.90Å" /> | caption="1m8r, resolution 1.90Å" /> | ||
'''Crystal Structures of Cadmium-binding Acidic Phospholipase A2 from the Venom of Agkistrodon halys pallas at 1.9 Resolution (crystal grown at pH 7.4)'''<br /> | '''Crystal Structures of Cadmium-binding Acidic Phospholipase A2 from the Venom of Agkistrodon halys pallas at 1.9 Resolution (crystal grown at pH 7.4)'''<br /> | ||
==Overview== | ==Overview== | ||
Phospholipase A(2) coordinates Ca(2+) ion through three carbonyl oxygen | Phospholipase A(2) coordinates Ca(2+) ion through three carbonyl oxygen atoms of residues 28, 30, and 32, two carboxyl oxygen atoms of residue Asp49, and two (or one) water molecules, forming seven (or six) coordinate geometry of Ca(2+) ligands. Two crystal structures of cadmium-binding acidic phospholipase A(2) from the venom of Agkistrodon halys Pallas (i.e., Agkistrodon blomhoffii brevicaudus) at different pH values (5.9 and 7.4) were determined to 1.9A resolution by the isomorphous difference Fourier method. The well-refined structures revealed that a Cd(2+) ion occupied the position expected for a Ca(2+) ion, and that the substitution of Cd(2+) for Ca(2+) resulted in detectable changes in the metal-binding region: one of the carboxyl oxygen atoms from residue Asp49 was farther from the metal ion while the other one was closer and there were no water molecules coordinating to the metal ion. Thus the Cd(2+)-binding region appears to have four coordinating oxygen ligands. The cadmium binding to the enzyme induced no other significant conformational change in the enzyme molecule elsewhere. The mechanism for divalent cadmium cation to support substrate binding but not catalysis is discussed. | ||
==About this Structure== | ==About this Structure== | ||
1M8R is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Gloydius_halys Gloydius halys] with CD and BU1 as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Phospholipase_A(2) Phospholipase A(2)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.1.4 3.1.1.4] Full crystallographic information is available from [http:// | 1M8R is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Gloydius_halys Gloydius halys] with <scene name='pdbligand=CD:'>CD</scene> and <scene name='pdbligand=BU1:'>BU1</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Phospholipase_A(2) Phospholipase A(2)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.1.4 3.1.1.4] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1M8R OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: two beta]] | [[Category: two beta]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:52:41 2008'' | ||
Revision as of 14:52, 21 February 2008
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Crystal Structures of Cadmium-binding Acidic Phospholipase A2 from the Venom of Agkistrodon halys pallas at 1.9 Resolution (crystal grown at pH 7.4)
OverviewOverview
Phospholipase A(2) coordinates Ca(2+) ion through three carbonyl oxygen atoms of residues 28, 30, and 32, two carboxyl oxygen atoms of residue Asp49, and two (or one) water molecules, forming seven (or six) coordinate geometry of Ca(2+) ligands. Two crystal structures of cadmium-binding acidic phospholipase A(2) from the venom of Agkistrodon halys Pallas (i.e., Agkistrodon blomhoffii brevicaudus) at different pH values (5.9 and 7.4) were determined to 1.9A resolution by the isomorphous difference Fourier method. The well-refined structures revealed that a Cd(2+) ion occupied the position expected for a Ca(2+) ion, and that the substitution of Cd(2+) for Ca(2+) resulted in detectable changes in the metal-binding region: one of the carboxyl oxygen atoms from residue Asp49 was farther from the metal ion while the other one was closer and there were no water molecules coordinating to the metal ion. Thus the Cd(2+)-binding region appears to have four coordinating oxygen ligands. The cadmium binding to the enzyme induced no other significant conformational change in the enzyme molecule elsewhere. The mechanism for divalent cadmium cation to support substrate binding but not catalysis is discussed.
About this StructureAbout this Structure
1M8R is a Single protein structure of sequence from Gloydius halys with and as ligands. Active as Phospholipase A(2), with EC number 3.1.1.4 Full crystallographic information is available from OCA.
ReferenceReference
Structures of cadmium-binding acidic phospholipase A2 from the venom of Agkistrodon halys Pallas at 1.9A resolution., Xu S, Gu L, Jiang T, Zhou Y, Lin Z, Biochem Biophys Res Commun. 2003 Jan 10;300(2):271-7. PMID:12504079
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