4IB7

Bovine beta-lactoglobulin (isoform A) in complex with dodecyltrimethylammonium (DTAC)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.309 
  • R-Value Work: 0.238 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

The differences in binding 12-carbon aliphatic ligands by bovine beta-lactoglobulin isoform A and B studied by isothermal titration calorimetry and X-ray crystallography

Loch, J.I.Bonarek, P.Polit, A.Swiatek, S.Dziedzicka-Wasylewska, M.Lewinski, K.

(2013) J.Mol.Recognit. 26: 357-367

  • DOI: 10.1002/jmr.2280
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Isoforms A (LGB-A) and B (LGB-B) of bovine lactoglobulin, the milk protein, differ in positions 64 (D↔G) and 118 (V↔A). Interactions of LGB-A and LGB-B with sodium dodecyl sulfate (SDS), dodecyltrimethylammonium chloride (DTAC) and lauric acid (LA), ...

    Isoforms A (LGB-A) and B (LGB-B) of bovine lactoglobulin, the milk protein, differ in positions 64 (D↔G) and 118 (V↔A). Interactions of LGB-A and LGB-B with sodium dodecyl sulfate (SDS), dodecyltrimethylammonium chloride (DTAC) and lauric acid (LA), 12-carbon ligands possessing differently charged polar groups, were investigated using isothermal titration calorimetry and X-ray crystallography, to study the proton linkage phenomenon and to distinguish between effects related to different isoforms and different ligand properties. The determined values of ΔS and ΔH revealed that for all ligands, binding is entropically driven. The contribution from enthalpy change is lower and shows strong dependence on type of buffer that indicates proton release from the protein varying with protein isoform and ligand type and involvement of LA and Asp64 (in isoform A) in this process. The ligand affinities for both isoforms were arranged in the same order, DTAC < LA < SDS, and were systematically lower for variant B. The entropy change of the complexation process was always higher for isoform A, but these values were compensated by changes in enthalpy, resulting in almost identical ΔG for complexes of both isoforms. The determined crystal structures showed that substitution in positions 64 and 118 did not influence the overall structure of LGB complexes. The chemical character of the ligand polar group did not affect the position of its aliphatic chain in protein β-barrel, indicating a major role of hydrophobic interactions in ligand binding that prevailed even with the repulsion between positively charged DTAC and lysine residues located at binding site entrance.


    Organizational Affiliation

    Jagiellonian University, Faculty of Chemistry, Department of Crystal Chemistry and Crystal Physics, Ingardena 3, 30-060 Kraków, Poland.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
beta-lactoglobulin
A
162Bos taurusMutation(s): 0 
Gene Names: LGB
Find proteins for P02754 (Bos taurus)
Go to UniProtKB:  P02754
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CAT
Query on CAT

Download SDF File 
Download CCD File 
A
DODECANE-TRIMETHYLAMINE
C15 H34 N
VICYBMUVWHJEFT-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.309 
  • R-Value Work: 0.238 
  • Space Group: P 32 2 1
Unit Cell:
Length (Å)Angle (°)
a = 53.640α = 90.00
b = 53.640β = 90.00
c = 109.880γ = 120.00
Software Package:
Software NamePurpose
MOLREPphasing
CrysalisProdata collection
REFMACrefinement
CrysalisProdata reduction
SCALAdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2013-06-26
    Type: Initial release
  • Version 1.1: 2013-07-17
    Type: Database references
  • Version 1.2: 2017-09-20
    Type: Database references