PDBsum entry: 1uoo

Hydrolase

PDB id: 1uoo

Contents

Protein chain

710 a.a. *

Ligands

GLY-PHE-ARG-PRO

GOL

Waters ×300

* Residue conservation analysis

PDB id:

1uoo

Name:

Hydrolase

Title:

Prolyl oligopeptidase from porcine brain, s554a mutant with bound peptide ligand gly-phe-arg-pro

Structure:

Prolyl endopeptidase. Chain: a. Synonym: post-proline cleaving enzyme, pe, prep. Engineered: yes. Mutation: yes. Other_details: engineered mutation ser 554 ala. Peptide ligand gly-phe-arg-pro. Chain: b. Engineered: yes

Source:

Sus scrofa. Pig. Organism_taxid: 9823. Tissue: brain. Expressed in: escherichia coli. Expression_system_taxid: 562. Synthetic: yes

Biol. unit:

Dimer (from PDB file)

Resolution:

2.35Å R-factor: 0.195 R-free: 0.237

Authors:

D.Rea,V.Fulop

Key ref:

Z.Szeltner et al. (2003). Electrostatic environment at the active site of prolyl oligopeptidase is highly influential during substrate binding. J Biol Chem, 278, 48786-48793. PubMed id: 14514675 DOI: 10.1074/jbc.M309555200

Date:

22-Sep-03 Release date: 02-Oct-03

Protein chain

P23687  (PPCE_PIG) -  Prolyl endopeptidase

Seq: 710 a.a.

Struc: 710 a.a.*

* PDB and UniProt seqs differ at 1 residue position (black cross)

Enzyme reactions

• Enzyme class: E.C.3.4.21.26 - Prolyl oligopeptidase.
• Reaction: Hydrolysis of Pro-|-Xaa >> Ala-|-Xaa in oligopeptides.

 Gene Ontology (GO) functional annotation 

• Cellular component: cytoplasm (1 term)
• Biological process: proteolysis (1 term)
• Biochemical function: hydrolase activity (5 terms)

DOI no: 10.1074/jbc.M309555200

J Biol Chem 278:48786-48793 (2003)

PubMed id: 14514675

Electrostatic environment at the active site of prolyl oligopeptidase is highly influential during substrate binding.

Z.Szeltner, D.Rea, V.Renner, L.Juliano, V.Fülop, L.Polgár.

ABSTRACT

The positive electrostatic environment of the active site of prolyl oligopeptidase was investigated by using substrates with glutamic acid at positions P2, P3, P4, and P5, respectively. The different substrates gave various pH rate profiles. The pKa values extracted from the curves are apparent parameters, presumably affected by the nearby charged residues, and do not reflect the ionization of a simple catalytic histidine as found in the classic serine peptidases like chymotrypsin and subtilisin. The temperature dependence of kcat/Km did not produce linear Arrhenius plots, indicating different changes in the individual rate constants with the increase in temperature. This rendered it possible to calculate these constants, i.e. the formation (k1) and decomposition (k-1) of the enzyme-substrate complex and the acylation constant (k2), as well as the corresponding activation energies. The results have revealed the relationship between the complex Michaelis parameters and the individual rate constants. Structure determination of the enzyme-substrate complexes has shown that the different substrates display a uniform binding mode. None of the glutamic acids interacts with a charged group. We conclude that the specific rate constant is controlled by k1 rather than k2 and that the charged residues from the substrate and the enzyme can markedly affect the formation but not the structure of the enzyme-substrate complexes.

Selected figure(s)

Figure 2.
FIG. 2. The pH rate profiles for the reactions of prolyl oligopeptidase ( ) and its R252S variant ( ) with the substrate containing P3 Glu.

Figure 4.
FIG. 4. Arrhenius plots for k[cat]. Shown are Arg at the P2 (x), Glu at the P3 ( ), and Glu at the P5 ( ) positions.

The above figures are reprinted by permission from the ASBMB: J Biol Chem (2003, 278, 48786-48793) copyright 2003.

Figures were selected by an automated process.