Sekar, K and Gayathri, D and Velmurugan, D and Jeyakanthan, J and Yamane, T and Poi, MJ and Tsai, MD (2006) Third calcium ion found in an inhibitor-bound phospholipase A2. In: Acta Crystallographica Section D-Biological Crystallography, 62 (4). 392 -397.
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The lipolytic enzyme phospholipase A(2) plays a crucial role in lipid metabolism and catalyzes hydrolysis of the fatty-acid ester bond at the sn-2 position of phospholipids. Here, the crystal structure (1.7 angstrom resolution) of the triple mutant (K53,56,121M) of bovine pancreatic phospholipase A2 complexed with an organic molecule, p-methoxybenzoic acid (anisic acid), is reported. Residues 60-70 (the surface-loop residues) are ordered and adopt conformations which are different from those normally found in structures in which a second calcium ion is present. It is interesting to note that for the first time a third calcium ion has been identified. In addition, four Tris (2-amino-2-hydroxymethyl-1,3-propanediol) molecules were located. It is believed that one of the Tris molecules plays a role in clamping the third calcium ion and that another is involved in controlling the dynamics of the surface loop through hydrogen bonds.
|Item Type:||Journal Article|
|Additional Information:||Copyright of this article belongs to International Union of Crystallography.|
|Keywords:||phospholipase A2;anisic acid.|
|Department/Centre:||Division of Information Sciences > Supercomputer Education & Research Centre|
|Date Deposited:||13 Apr 2009 05:57|
|Last Modified:||19 Sep 2010 04:59|
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