Biological Assembly 1  

 3D View: Structure | Electron Density

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 2-mer - A1B 

Biological assembly 1 assigned by authors and generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 32.03 kDa 
• Atom Count: 2291 
• Residue Count: 301 
• Unique protein chains: 2

1CGI

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

• DOI: 10.2210/pdb1CGI/pdb

• Classification: SERINE PROTEASE/INHIBITOR COMPLEX
• Organism(s): Bos taurus, Homo sapiens
• Mutation(s): No 


• Deposited: 1991-10-08 Released: 1993-10-31 
• Deposition Author(s): Hecht, H.J., Szardenings, M., Collins, J., Schomburg, D.

---

Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.30 Å
• R-Value Observed: 0.195 

Literature

Three-dimensional structure of the complexes between bovine chymotrypsinogen A and two recombinant variants of human pancreatic secretory trypsin inhibitor (Kazal-type).

Hecht, H.J., Szardenings, M., Collins, J., Schomburg, D.

(1991) J Mol Biol 220: 711-722

• PubMed: 1870127 
• DOI: 10.1016/0022-2836(91)90112-j
• Structures With Same Primary Citation


• 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.

---

Organizational Affiliation: 

GBF (Gesellschaft für Biotechnologische Forschung), Department of Molecular Structure Research, Braunschweig, Germany.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details
ALPHA-CHYMOTRYPSINOGEN	E	245	Bos taurus	Mutation(s): 0  EC: 3.4.21.1
Find proteins for P00766 (Bos taurus) Go to UniProtKB:  P00766

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details
PANCREATIC SECRETORY TRYPSIN INHIBITOR (KAZAL TYPE) VARIANT 3	I	56	Homo sapiens	Mutation(s): 0  Gene Names: SPINK1, PSTI
Find proteins for P00995 (Homo sapiens) Go to UniProtKB:  P00995
NIH Common Fund Data Resources
PHAROS  P00995 GTEx  ENSG00000164266

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.30 Å
• R-Value Observed: 0.195 
• Space Group: P 4₁ 2₁ 2

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 84.4	α = 90
b = 84.4	β = 90
c = 86.7	γ = 90

Software Package:

Software Name	Purpose
PROLSQ	refinement

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 1991-10-08 
• Released Date: 1993-10-31 
Deposition Author(s): Hecht, H.J., Szardenings, M., Collins, J., Schomburg, D.

Revision History 

• Version 1.0: 1993-10-31
  Type: Initial release
  
• Version 1.1: 2008-03-24
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance