3GYM

Structure of Prostasin in Complex with Aprotinin

Summary for 3GYM

• Entry DOI: 10.2210/pdb3gym/pdb
• Related: 3E1X 3EON 3FVF 3GYL
• Descriptor: Prostasin, Pancreatic trypsin inhibitor (2 entities in total)
• Functional Keywords: prostasin, hcap1, channel activating, aprotinin, inhibition, disulfide bond, pharmaceutical, protease inhibitor, secreted, serine protease inhibitor, cell membrane, glycoprotein, hydrolase, membrane, protease, serine protease, transmembrane, zymogen, hydrolase-inhibitor complex, hydrolase/inhibitor
• Biological source: Homo sapiens (Human); More
• Cellular location: Prostasin: Cell membrane; Single-pass membrane protein. Prostasin light chain: Secreted, extracellular space. Prostasin heavy chain: Secreted, extracellular space: Q16651; Secreted: P00974
• Total number of polymer chains: 4
• Total formula weight: 69508.24

Authors

Spraggon, G.,Hornsby, M.,Shipway, A.,Harris, J.L.,Lesley, S.A. (deposition date: 2009-04-03, release date: 2009-05-05, Last modification date: 2024-11-06)

Primary citation

Spraggon, G.,Hornsby, M.,Shipway, A.,Tully, D.C.,Bursulaya, B.,Danahay, H.,Harris, J.L.,Lesley, S.A.
Active site conformational changes of prostasin provide a new mechanism of protease regulation by divalent cations.
Protein Sci., 18:1081-1094, 2009

PubMed Abstract: Prostasin or human channel-activating protease 1 has been reported to play a critical role in the regulation of extracellular sodium ion transport via its activation of the epithelial cell sodium channel. Here, the structure of the extracellular portion of the membrane associated serine protease has been solved to high resolution in complex with a nonselective d-FFR chloromethyl ketone inhibitor, in an apo form, in a form where the apo crystal has been soaked with the covalent inhibitor camostat and in complex with the protein inhibitor aprotinin. It was also crystallized in the presence of the divalent cation Ca(+2). Comparison of the structures with each other and with other members of the trypsin-like serine protease family reveals unique structural features of prostasin and a large degree of conformational variation within specificity determining loops. Of particular interest is the S1 subsite loop which opens and closes in response to basic residues or divalent ions, directly binding Ca(+2) cations. This induced fit active site provides a new possible mode of regulation of trypsin-like proteases adapted in particular to extracellular regions with variable ionic concentrations such as the outer membrane layer of the epithelial cell.

PubMed: 19388054
DOI: 10.1002/pro.118

Experimental method

X-RAY DIFFRACTION (2.8 Å)