1wo2
From Proteopedia
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Crystal structure of the pig pancreatic alpha-amylase complexed with malto-oligosaacharides under the effect of the chloride ion
Overview
Pig pancreatic alpha-amylase (PPA), an enzyme belonging to the, alpha-amylase family, is involved in the degradation of starch. Like some, other members of this family, PPA requires chloride to reach maximum, activity levels. To further explain the mechanism of chloride activation, a crystal of wild-type PPA soaked with maltopentaose using a chloride-free, buffer was analyzed by X-ray crystallography. A conspicuous reorientation, of the acid/base catalyst Glu233 residue was found to occur. The, structural results, along with kinetic data, show that the acid/base, catalyst is maintained in the active site, in an optimum position, pointing toward the scissile bond-atom, due to the presence of chloride, ions. The present study therefore explains the mechanism of PPA activation, by chloride ions.
About this Structure
1WO2 is a Single protein structure of sequence from Sus scrofa with CL, CA and EDO as ligands. Active as Alpha-amylase, with EC number 3.2.1.1 Full crystallographic information is available from OCA.
Reference
Molecular basis of the effects of chloride ion on the acid-base catalyst in the mechanism of pancreatic alpha-amylase., Qian M, Ajandouz el H, Payan F, Nahoum V, Biochemistry. 2005 Mar 8;44(9):3194-201. PMID:15736930
Page seeded by OCA on Wed Nov 21 05:33:33 2007
Categories: Alpha-amylase | Single protein | Sus scrofa | Nahoum, V. | Payan, F. | Qian, M. | CA | CL | EDO | Beta-alpha-barrels
