1B0C

EVIDENCE OF A COMMON DECAMER IN THREE CRYSTAL STRUCTURES OF BPTI, CRYSTALLIZED FROM THIOCYANATE, CHLORIDE OR SULFATE


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.80 Å
  • R-Value Free: 0.223 
  • R-Value Work: 0.198 
  • R-Value Observed: 0.198 

wwPDB Validation   3D Report Full Report


This is version 1.4 of the entry. See complete history


Literature

The BPTI decamer observed in acidic pH crystal forms pre-exists as a stable species in solution.

Hamiaux, C.Perez, J.Prange, T.Veesler, S.Ries-Kautt, M.Vachette, P.

(2000) J Mol Biol 297: 697-712

  • DOI: https://doi.org/10.1006/jmbi.2000.3584
  • Primary Citation of Related Structures:  
    1B0C, 1BZ5

  • PubMed Abstract: 

    Bovine pancreatic trypsin inhibitor (BPTI) crystallizes under acidic pH conditions in the presence of thiocyanate, chloride and sulfate ions, yielding three different polymorphs in P2(1), P6(4)22 and P6(3)22 space groups, respectively. In all three crystal forms, the same decamer is found in the packing (ten BPTI molecules organized through two perpendicular 2-fold and 5-fold axes as a well-defined and compact object) in contrast to the monomeric crystal forms observed at basic pH conditions. The crystallization of BPTI under acidic conditions (pH 4.5) was investigated by small angle X-ray scattering with both under- and supersaturated BPTI solutions. Data showed the oligomerization of BPTI molecules under all investigated conditions. Accordingly, various mixtures of discrete oligomers (n=1 to 10) were considered. Calculated scattering curves were obtained using models based on the crystallographic structures, and the experimental patterns were analyzed as a linear combination of the model curves using a non-linear curve fitting procedure. The results, confirmed by gel filtration experiments, unambiguously demonstrate the co-existence of two different BPTI particles in solution: a monomer and a decamer, with no evidence of any other intermediates. Moreover, using both approaches, the fraction of decamers was found to increase with increasing salt concentration, even beyond the solubility curve. We therefore propose that at acidic pH, BPTI crystallizes following a two step process: decamers are first built in under- and supersaturated solutions, upon which crystal growth proceeds by decamer stacking. Indeed, those BPTI crystals should best be described as "BPTI decamer" crystals.


  • Organizational Affiliation

    LURE (CNRS-CEA-MENRT), Centre Universitaire Paris-Sud, Bât 209 D, B. P. 34, Orsay Cedex, 91898, France. hamiaux@lure.u-psud.fr


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
PROTEIN (PANCREATIC TRYPSIN INHIBITOR)
A, B, C, D, E
58Bos taurusMutation(s): 0 
UniProt
Find proteins for P00974 (Bos taurus)
Explore P00974 
Go to UniProtKB:  P00974
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP00974
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.80 Å
  • R-Value Free: 0.223 
  • R-Value Work: 0.198 
  • R-Value Observed: 0.198 
  • Space Group: P 64 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 95.47α = 90
b = 95.47β = 90
c = 159.69γ = 120
Software Package:
Software NamePurpose
MOSFLMdata reduction
Agrovatadata reduction
ROTAVATAdata reduction
AMoREphasing
X-PLORrefinement
Agrovatadata scaling
ROTAVATAdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1998-11-11
    Type: Initial release
  • Version 1.1: 2008-04-27
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2017-10-04
    Changes: Refinement description
  • Version 1.4: 2023-08-09
    Changes: Data collection, Database references, Refinement description