1UZ2

The Cys121Ser Mutant of Beta-Lactoglobulin


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.267 
  • R-Value Work: 0.267 
  • R-Value Observed: 0.213 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

A recombinant C121S mutant of bovine beta-lactoglobulin is more susceptible to peptic digestion and to denaturation by reducing agents and heating.

Jayat, D.Gaudin, J.C.Chobert, J.M.Burova, T.V.Holt, C.McNae, I.Sawyer, L.Haertle, T.

(2004) Biochemistry 43: 6312-6321

  • DOI: 10.1021/bi0362469
  • Structures With Same Primary Citation

  • PubMed Abstract: 
  • The lipocalin beta-lactoglobulin (BLG) is the major whey protein of bovine milk and is homodimeric at physiological conditions. Each monomer contains two disulfide bonds and one cysteine at position 121 (C121). This free thiol plays an important role ...

    The lipocalin beta-lactoglobulin (BLG) is the major whey protein of bovine milk and is homodimeric at physiological conditions. Each monomer contains two disulfide bonds and one cysteine at position 121 (C121). This free thiol plays an important role in the heat-induced aggregation of BLG and, possibly, in its conformational stability. We describe here the expression in the yeast Pichia pastoris of a mutant bovine BLG, in which C121 was changed into Ser (C121S). Circular dichroism and high-performance liquid chromatography experiments, together with the X-ray crystal structure, show that the C121S mutant retains a nativelike fold at both neutral and acid pH. The mutation completely blocks the irreversible aggregation induced by heat treatment at 90 degrees C. Compared to the recombinant wild-type protein, the mutant is less stable to temperature and disulfide reducing agents and is much more sensitive to peptic digestion. Moreover, its affinity for 1-anilino-8-naphthalenesulfonate is increased at neutral and acid pH. We suggest that the stability of the protein arising from the hydrophobic effect is reduced by the C121S mutation so that unfolded or partially unfolded states are more favored.


    Related Citations: 
    • Crystal Structures of the Bovine Beta-Lactoglobulin in the Orthorhombic Space Group C2221: Structural Differences between Genetic Variants a and B and the Nature of Tanford Transition
      Oliveira, K.M.G., Valente-Mesquita, V.L., Botelho, M.M., Sawyer, L., Ferreira, S.T., Polikarpov, I.
      (2001) Eur J Biochem 268: 477
    • Expression of Recombinant Wild Type and Mutant Beta-Lactoglobulin in the Yeast Pichia Pastoris
      Wilson, C., Quarrie, L., Allan, G.J., Flint, D.J., Sawyer, L., Holt, C.
      (1999) Int J Food Sci Technol 34: 445

    Organizational Affiliation

    Laboratoire d'Etude des Interactions des Molécules Alimentaires, Institut National de la Recherche Agronomique, rue de la Géraudière, B.P. 71627, 44316 Nantes Cedex 3, France.



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
BETA-LACTOGLOBULINX162Bos taurusMutation(s): 1 
Gene Names: LGB
Find proteins for P02754 (Bos taurus)
Explore P02754 
Go to UniProtKB:  P02754
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.267 
  • R-Value Work: 0.267 
  • R-Value Observed: 0.213 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 55.69α = 90
b = 80.47β = 90
c = 66.59γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
MOSFLMdata reduction
SCALAdata scaling
CNSphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2004-05-20
    Type: Initial release
  • Version 1.1: 2014-02-19
    Changes: Database references, Derived calculations, Non-polymer description, Other, Source and taxonomy, Structure summary, Version format compliance
  • Version 1.2: 2019-01-16
    Changes: Data collection, Database references, Derived calculations
  • Version 1.3: 2019-05-08
    Changes: Data collection, Experimental preparation