2FO5

Crystal structure of recombinant barley cysteine endoprotease B isoform 2 (EP-B2) in complex with leupeptin

Summary for 2FO5

• Entry DOI: 10.2210/pdb2fo5/pdb
• Related PRD ID: PRD_000216
• Descriptor: Cysteine proteinase EP-B 2, ACE-LEU-LEU-argininal (leupeptin), SULFATE ION, ... (4 entities in total)
• Functional Keywords: ep-b2, epb2, epb, cysteine endoprotease, endopeptidase, leupeptin, hydrolase, hydrolase-hydrolase inhibitor complex, hydrolase/hydrolase inhibitor
• Biological source: Hordeum vulgare; More
• Total number of polymer chains: 8
• Total formula weight: 113621.65

Authors

Bethune, M.T.,Strop, P.,Brunger, A.T.,Khosla, C. (deposition date: 2006-01-12, release date: 2006-07-18, Last modification date: 2024-11-20)

Primary citation

Bethune, M.T.,Strop, P.,Tang, Y.,Sollid, L.M.,Khosla, C.
Heterologous Expression, Purification, Refolding, and Structural-Functional Characterization of EP-B2, a Self-Activating Barley Cysteine Endoprotease.
Chem.Biol., 13:637-647, 2006

PubMed Abstract: 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.

PubMed: 16793521
DOI: 10.1016/j.chembiol.2006.04.008

Experimental method

X-RAY DIFFRACTION (2.2 Å)