Three-dimensional structure of a recombinant variant of human pancreatic secretory trypsin inhibitor (Kazal type)

J Mol Biol. 1992 Jun 20;225(4):1095-103. doi: 10.1016/0022-2836(92)90107-u.

Abstract

A modified version of the human pancreatic trypsin inhibitor (PSTI), generated in a protein-design project, has been crystallized in spacegroup P4(3) with lattice constants a = 40.15 A, c = 33.91 A. The structure has been solved by molecular replacement. Refinement of the structure by simulated annealing and conventional restrained least-squares yielded for 8.0 to 2.3 A data a final R-value of 19.1%. Differences to the known structures of porcine PSTI complexed with trypsinogen and modified human PSTI complexed with chymotrypsinogen occur at the flexible N-terminal part of the molecule. These differences are influenced by crystal packing, as are low temperature factors for the binding loop. The geometry of the binding loop is similar to the complexed structures.

Publication types

  • Comparative Study

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Crystallization
  • Genetic Variation
  • Humans
  • Models, Molecular
  • Molecular Sequence Data
  • Plasmids
  • Protein Conformation
  • Recombinant Proteins / chemistry
  • Sequence Homology, Nucleic Acid
  • Swine
  • Thermodynamics
  • Trypsin Inhibitor, Kazal Pancreatic / chemistry*
  • Trypsin Inhibitor, Kazal Pancreatic / genetics
  • X-Ray Diffraction / methods

Substances

  • Recombinant Proteins
  • Trypsin Inhibitor, Kazal Pancreatic