1CGI

THREE-DIMENSIONAL STRUCTURE OF THE COMPLEXES BETWEEN BOVINE CHYMOTRYPSINOGEN*A AND TWO RECOMBINANT VARIANTS OF HUMAN PANCREATIC SECRETORY TRYPSIN INHIBITOR (KAZAL-TYPE)

Summary for 1CGI

• Entry DOI: 10.2210/pdb1cgi/pdb
• Descriptor: ALPHA-CHYMOTRYPSINOGEN, PANCREATIC SECRETORY TRYPSIN INHIBITOR (KAZAL TYPE) VARIANT 3 (3 entities in total)
• Functional Keywords: serine protease-inhibitor complex, serine protease-inhibitor complex complex, serine protease/inhibitor complex
• Biological source: Bos taurus (cattle); More
• Cellular location: Secreted, extracellular space: P00766; Secreted: P00995
• Total number of polymer chains: 2
• Total formula weight: 32033.13

Authors

Hecht, H.J.,Szardenings, M.,Collins, J.,Schomburg, D. (deposition date: 1991-10-08, release date: 1993-10-31, Last modification date: 2024-10-30)

Primary citation

Hecht, H.J.,Szardenings, M.,Collins, J.,Schomburg, D.
Three-dimensional structure of the complexes between bovine chymotrypsinogen A and two recombinant variants of human pancreatic secretory trypsin inhibitor (Kazal-type).
J.Mol.Biol., 220:711-722, 1991

PubMed Abstract: Variants of the human pancreatic secretory trypsin inhibitor (PSTI) have been created during a protein design project to generate a high-affinity inhibitor with respect to some serine proteases other than trypsin. Two modified versions of human PSTI with high affinity for chymotrypsin were crystallized as a complex with chymotrypsinogen. Both crystallize isomorphously in space group P4(1)2(1)2 with lattice constants a = 84.4 A, c = 86.7 A and diffract to 2.3 A resolution. The structure was solved by molecular replacement. The final R-value after refinement with 8.0 to 2.3 A resolution data was 19.5% for both complexes after inclusion of about 50 bound water molecules. The overall three-dimensional structure of PSTI is similar to the structure of porcine PSTI in the trypsinogen complex (1TGS). Small differences in the relative orientation of the binding loop and the core of the inhibitors indicate flexible adaptation to the proteases. The chymotrypsinogen part of the complex is similar to chymotrypsin. After refolding induced by binding of the inhibitor the root-mean-square difference of the active site residues A186 to A195 and A217 to A222 compared to chymotrypsin was 0.26 A.

PubMed: 1870127
DOI: 10.1016/0022-2836(91)90112-J

Experimental method

X-RAY DIFFRACTION (2.3 Å)