1O6F: PROLYL OLIGOPEPTIDASE FROM PORCINE BRAIN, D641A MUTANT WITH BOUND PEPTIDE LIGAND SUC-GLY-PRO

Citation:
Abstract
Prolyl oligopeptidase, a serine peptidase unrelated to trypsin and subtilisin, is implicated in memory disorders and is an important target of drug design. The catalytic competence of the Asp(641) residue of the catalytic triad (Ser(554), Asp(641), His(680)) was studied using the D641N and D641A variants of the enzyme. Both variants displayed 3 orders of magnitude reduction in k(cat)/K(m) for benzyloxycarbonyl-Gly-Pro-2-naphthylamide. Using an octapeptide substrate, the decrease was 6 orders of magnitude, whereas with Z-Gly-Pro-4-nitrophenyl ester there was virtually no change in k(cat)/K(m). This indicates that the contribution of Asp(641) is very much dependent on the substrate-leaving group, which was not the case for the classic serine peptidase, trypsin. The rate constant for benzyloxycarbonyl-Gly-Pro-thiobenzylester conformed to this series as demonstrated by a method designed for monitoring the hydrolysis of thiolesters in the presence of thiol groups. Alkylation of His(680) with Z-Gly-Pro-CH(2)Cl was concluded with similar rate constants for wild-type and D641A variant. However, kinetic measurements with Z-Gly-Pro-OH, a product-like inhibitor, indicated that the His(680) is not accessible in the enzyme variants. Crystal structure determination of these mutants revealed subtle perturbations related to the catalytic activity. Many of these observations show differences in the catalysis between trypsin and prolyl oligopeptidase.
PDB ID: 1O6FDownload
MMDB ID: 106041
PDB Deposition Date: 2002/9/15
Updated in MMDB: 2012/12
Experimental Method:
x-ray diffraction
Resolution: 1.6  Å
Similar Structures:
Biological Unit for 1O6F: monomeric; determined by author and by software (PQS)
Molecular Components in 1O6F
Label Count Molecule
Protein (1 molecule)
1
Prolyl Endopeptidase(Gene symbol: PREP)
Molecule annotation
Chemicals (6 molecules)
1
1
2
1
3
1
4
3
* Click molecule labels to explore molecular sequence information.

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