1FKQ

RECOMBINANT GOAT ALPHA-LACTALBUMIN T29V


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.80 Å
  • R-Value Free: 0.241 
  • R-Value Work: 0.189 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Contribution of Thr29 to the thermodynamic stability of goat alpha-lactalbumin as determined by experimental and theoretical approaches.

Horii, K.Saito, M.Yoda, T.Tsumoto, K.Matsushima, M.Kuwajima, K.Kumagai, I.

(2001) Proteins 45: 16-29

  • DOI: 10.1002/prot.1119
  • Primary Citation of Related Structures:  
    1FKQ, 1FKV

  • PubMed Abstract: 
  • The Thr29 residue in the hydrophobic core of goat alpha-lactalbumin (alpha-LA) was substituted with Val (Thr29Val) and Ile (Thr29Ile) to investigate the contribution of Thr29 to the thermodynamic stability of the protein. We carried out protein stability measurements, X-ray crystallographic analyses, and free energy calculations based on molecular dynamics simulation ...

    The Thr29 residue in the hydrophobic core of goat alpha-lactalbumin (alpha-LA) was substituted with Val (Thr29Val) and Ile (Thr29Ile) to investigate the contribution of Thr29 to the thermodynamic stability of the protein. We carried out protein stability measurements, X-ray crystallographic analyses, and free energy calculations based on molecular dynamics simulation. The equilibrium unfolding transitions induced by guanidine hydrochloride demonstrated that the Thr29Val and Thr29Ile mutants were, respectively, 1.9 and 3.2 kcal/mol more stable than the wild-type protein (WT). The overall structures of the mutants were almost identical to that of WT, in spite of the disruption of the hydrogen bonding between the side-chain O-H group of Thr29 and the main-chain C=O group of Glu25. To analyze the stabilization mechanism of the mutants, we performed free energy calculations. The calculated free energy differences were in good agreement with the experimental values. The stabilization of the mutants was mainly caused by solvation loss in the denatured state. Furthermore, the O-H group of Thr29 favorably interacts with the C=O group of Glu25 to form hydrogen bonds and, simultaneously, unfavorably interacts electrostatically with the main-chain C=O group of Thr29. The difference in the free energy profile of the unfolding path between WT and the Thr29Ile mutant is discussed in light of our experimental and theoretical results.


    Related Citations: 
    • Effect of the extra N-terminal Methionine residue on the stability and folding of recombinant alpha-lactalbumin expressed in Escherichia coli
      Chaudhuri, T.K., Horii, K., Yoda, T., Arai, M., Nagata, S., Terada, T.P., Uchiyama, H., Ikura, T., Tsumoto, K., Kataoka, H., Matsushima, M., Kuwajima, K., Kumagai, I.
      (1999) J Mol Biol 285: 1179

    Organizational Affiliation

    Department of Biomolecular Engineering, Graduate School of Engineering, Tohoku University, Sendai, Japan.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
ALPHA-LACTALBUMINA124Capra hircusMutation(s): 1 
Gene Names: A CLONED GENE OF GOAT LACTALALBA
EC: 2.4.1.22
Find proteins for P00712 (Capra hircus)
Explore P00712 
Go to UniProtKB:  P00712
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CA
Query on CA

Download CCD File 
A
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.80 Å
  • R-Value Free: 0.241 
  • R-Value Work: 0.189 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 42.75α = 90
b = 59.38β = 90
c = 45.14γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
X-PLORmodel building
X-PLORrefinement
X-PLORphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2001-02-14
    Type: Initial release
  • Version 1.1: 2008-04-27
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance