3UOU

Crystal structure of the Kunitz-type protease inhibitor ShPI-1 Lys13Leu mutant in complex with pancreatic elastase

Summary for 3UOU

• Entry DOI: 10.2210/pdb3uou/pdb
• Descriptor: Chymotrypsin-like elastase family member 1, Kunitz-type proteinase inhibitor SHPI-1, SULFATE ION, ... (5 entities in total)
• Functional Keywords: protein-protein interaction, hydrolase (serine protease), kunitz-type inhibitor, hydrolase-hydrolase inhibitor complex, hydrolase/hydrolase inhibitor
• Biological source: Stichodactyla helianthus (Carribean sea anemone); More
• Cellular location: Secreted: P00772 P31713
• Total number of polymer chains: 2
• Total formula weight: 33451.15

Authors

Garcia-Fernandez, R.,Perbandt, M.,Rehders, D.,Gonzalez-Gonzalez, Y.,Chavez, M.A.,Betzel, C.,Redecke, L. (deposition date: 2011-11-17, release date: 2012-11-21, Last modification date: 2024-11-20)

Primary citation

Garcia-Fernandez, R.,Perbandt, M.,Rehders, D.,Ziegelmuller, P.,Piganeau, N.,Hahn, U.,Betzel, C.,Chavez, M.A.,Redecke, L.
Three-dimensional Structure of a Kunitz-type Inhibitor in Complex with an Elastase-like Enzyme.
J.Biol.Chem., 290:14154-14165, 2015

PubMed Abstract: Elastase-like enzymes are involved in important diseases such as acute pancreatitis, chronic inflammatory lung diseases, and cancer. Structural insights into their interaction with specific inhibitors will contribute to the development of novel anti-elastase compounds that resist rapid oxidation and proteolysis. Proteinaceous Kunitz-type inhibitors homologous to the bovine pancreatic trypsin inhibitor (BPTI) provide a suitable scaffold, but the structural aspects of their interaction with elastase-like enzymes have not been elucidated. Here, we increased the selectivity of ShPI-1, a versatile serine protease inhibitor from the sea anemone Stichodactyla helianthus with high biomedical and biotechnological potential, toward elastase-like enzymes by substitution of the P1 residue (Lys(13)) with leucine. The variant (rShPI-1/K13L) exhibits a novel anti-porcine pancreatic elastase (PPE) activity together with a significantly improved inhibition of human neuthrophil elastase and chymotrypsin. The crystal structure of the PPE·rShPI-1/K13L complex determined at 2.0 Å resolution provided the first details of the canonical interaction between a BPTI-Kunitz-type domain and elastase-like enzymes. In addition to the essential impact of the variant P1 residue for complex stability, the interface is improved by increased contributions of the primary and secondary binding loop as compared with similar trypsin and chymotrypsin complexes. A comparison of the interaction network with elastase complexes of canonical inhibitors from the chelonian in family supports a key role of the P3 site in ShPI-1 in directing its selectivity against pancreatic and neutrophil elastases. Our results provide the structural basis for site-specific mutagenesis to further improve the binding affinity and/or direct the selectivity of BPTI-Kunitz-type inhibitors toward elastase-like enzymes.

PubMed: 25878249
DOI: 10.1074/jbc.M115.647586

Experimental method

X-RAY DIFFRACTION (2 Å)