2FO5 image
Entry Detail
PDB ID:
2FO5
Title:
Crystal structure of recombinant barley cysteine endoprotease B isoform 2 (EP-B2) in complex with leupeptin
Biological Source:
PDB Version:
Deposition Date:
2006-01-12
Release Date:
2006-07-18
Method Details:
Experimental Method:
Resolution:
2.20 Å
R-Value Free:
0.23
R-Value Work:
0.20
Space Group:
P 1
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Cysteine proteinase EP-B 2
Chain IDs:A, B, C, D
Chain Length:262
Number of Molecules:4
Biological Source:Hordeum vulgare
Polymer Type:polypeptide(L)
Description:ACE-LEU-LEU-argininal (leupeptin)
Chain IDs:E, F, G, H
Chain Length:4
Number of Molecules:4
Biological Source:Actinomycetes Streptomyces roseus MA 839-A1
Ligand Molecules
Peptide-like Molecules
PRD_000216
Primary Citation
Heterologous Expression, Purification, Refolding, and Structural-Functional Characterization of EP-B2, a Self-Activating Barley Cysteine Endoprotease.
Chem.Biol. 13 637 647 (2006)
PMID: 16793521 DOI: 10.1016/j.chembiol.2006.04.008

Abstact

We describe the heterologous expression in Escherichia coli of the proenzyme precursor to EP-B2, a cysteine endoprotease from germinating barley seeds. High yields (50 mg/l) of recombinant proEP-B2 were obtained from E. coli inclusion bodies in shake flask cultures following purification and refolding. The zymogen was rapidly autoactivated to its mature form under acidic conditions at a rate independent of proEP-B2 concentration, suggesting a cis mechanism of autoactivation. Mature EP-B2 was stable and active over a wide pH range and efficiently hydrolyzed a recombinant wheat gluten protein, alpha2-gliadin, at sequences with known immunotoxicity in celiac sprue patients. The X-ray crystal structure of mature EP-B2 bound to leupeptin was solved to 2.2 A resolution and provided atomic insights into the observed subsite specificity of the endoprotease. Our findings suggest that orally administered proEP-B2 may be especially well suited for treatment of celiac sprue.

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