Beta-lactoglobulin denaturation by dissociation-coupled unfolding

D Galani, Richard KO Apenten

Research output: Contribution to journalArticlepeer-review

27 Citations (Scopus)

Abstract

Many food proteins have multiple subunits. Beta-lactoglobulin (beta-1g) dimer was assessed for its resistance to subunit dissociation and unfolding in 0-8 M urea. Equilibrium denaturation profiles were monitored by ultraviolet difference spectrophotometry. The results were analysed by a new dissociation coupled unfolding (DCU) model. The Gibbs free energy change for denaturing beta-1g (Delta G(DCU)(0)) was 60 (+/- 2.3) kJ mol(-1) at pH 7 and 72 (+/- 1.6) kJ mol(-1) at pH 2.6. By comparison, the dissociation free energy for beta-1g dimer (Delta G(D)) is 26.0 kJ mol(-1) at pH 7 and 22.6 kJ mol(-1) at pH 2.6. Hence, dimerization accounts for 43% (pH 7) and 32% (pH 2.6) of the stability of native beta-1g dimer. Such results indicate a 3-state denaturation process in urea with native beta-1g monomer acting as a stable intermediate during DCU. The issues raised by a study of beta-1g may be relevant to other multisubunit proteins in food systems.
Original languageEnglish
Pages (from-to)93-100
JournalFood Research International
Volume32
Issue number2
Publication statusPublished - 1999

Bibliographical note

Reference text: 1. ALBERTY RA
PHYSICAL CHEM : 150 1992
2. ALEXANDER SS
COMPARISON OF DENATURATION OF BOVINE BETA-LACTOGLOBULINS-A AND B AND GOAT BETA-LACTOGLOBULIN
BIOCHEMISTRY 10 : 2738 1971
3. APENTEN RKO
The effect of protein unfolding stability on their rates of irreversible denaturation
FOOD HYDROCOLLOIDS 12 : 1 1998
4. APENTEN RKO
Protein stability function relations: beta-lactoglobulin-A sulphydryl group reactivity and its relationship to protein unfolding stability
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES 23 : 19 1998
5. APENTEN RKO
THERMODYNAMIC PARAMETERS FOR 3-STATE THERMAL-DENATURATION OF HUMAN AND BOVINE ALPHA-LACTALBUMIN
THERMOCHIMICA ACTA 262 : 1 1995
6. ARMSTRONG J
ON FRACTIONATION OF BETA-LACTOGLOBULIN AND ALPHA-LACTALBUMIN
BIOCHIMICA ET BIOPHYSICA ACTA 147 : 60 1967
7. ARMSTRONG JM
ON COLUMN CHROMATOGRAPHY OF BOVINE WHEY PROTEINS
BIOCHIMICA ET BIOPHYSICA ACTA 214 : 419 1970
8. AYMARD P
The effect of temperature and ionic strength on the dimerisation of beta-lactoglobulin
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES 19 : 213 1996
9. BOWIE JU
EQUILIBRIUM DISSOCIATION AND UNFOLDING OF THE ARC REPRESSOR DIMER
BIOCHEMISTRY 28 : 7139 1989
10. BROWNLOW S
Bovine beta-lactoglobulin at 1.8 angstrom resolution - Still an enigmatic lipocalin
STRUCTURE 5 : 481 1997
11. CHENG XD
ENERGETICS OF INTERSUBUNIT AND INTRASUBUNIT INTERACTIONS OF ESCHERICHIA-COLI ADENOSINE CYCLIC 3',5'-PHOSPHATE RECEPTOR PROTEIN
BIOCHEMISTRY 32 : 8130 1993
12. CREAMER LK
EFFECT OF SODIUM DODECYL-SULFATE AND PALMITIC ACID ON THE EQUILIBRIUM UNFOLDING OF BOVINE BETA-LACTOGLOBULIN
BIOCHEMISTRY 34 : 7170 1995
13. CUPO JF
CONFORMATIONAL STABILITY OF MIXED DISULFIDE DERIVATIVES OF BETA-LACTOGLOBULIN-B
BIOCHEMISTRY 22 : 2654 1983
14. ELOFSSON UM
Adsorption of beta-lactoglobulin A and B in relation to self-association: Effect of concentration and pH
LANGMUIR 13 : 1695 1997
15. GRANT SK
USE OF PROTEIN UNFOLDING STUDIES TO DETERMINE THE CONFORMATIONAL AND DIMERIC STABILITIES OF HIV-1 AND SIV PROTEASES
BIOCHEMISTRY 31 : 9491 1992
16. HEROLD M
REVERSIBLE DISSOCIATION AND UNFOLDING OF ASPARTATE-AMINOTRANSFERASE FROM ESCHERICHIA-COLI - CHARACTERIZATION OF A MONOMERIC INTERMEDIATE
BIOCHEMISTRY 29 : 1907 1990
17. IWABUCHI S
THERMAL-DENATURATION OF BETA-CONGLYCININ - KINETIC RESOLUTION OF REACTION-MECHANISM
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 39 : 27 1991
18. JAENICKE R
PROTEIN STRUCTURE PR : 117 1989
19. JOSS LA
beta-lactoglobulin B: A proposed standard for the study of reversible self-association reactions in the analytical ultracentrifuge?
ANALYTICAL BIOCHEMISTRY 236 : 20 1996
20. KELLA NKD
ENHANCED THERMODYNAMIC STABILITY OF BETA-LACTOGLOBULIN AT LOW PH - A POSSIBLE MECHANISM
BIOCHEMICAL JOURNAL 255 : 113 1988
21. KELLA NKD
STRUCTURAL STABILITY OF BETA-LACTOGLOBULIN IN THE PRESENCE OF KOSMOTROPIC SALTS - A KINETIC AND THERMODYNAMIC STUDY
INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH 32 : 396 1988
22. KELLY MJ
THERMODYNAMIC ANALYSIS OF MONOMER-DIMER ASSOCIATION OF BETA-LACTOGLOBULIN-A AT ISOELECTRIC POINT
BIOCHEMISTRY 10 : 2639 1971
23. LAPANJE S
CALORIMETRIC AND CIRCULAR DICHROIC STUDIES OF THE THERMAL-DENATURATION OF BETA-LACTOGLOBULIN
BIOPHYSICAL CHEMISTRY 34 : 155 1989
24. MANN CJ
TRYPTOPHAN REPLACEMENTS IN THE TRP APOREPRESSOR FROM ESCHERICHIA-COLI - PROBING THE EQUILIBRIUM AND KINETIC FOLDING MODELS
PROTEIN SCIENCE 2 : 1853 1993
25. MATSUURA JE
HEAT-INDUCED GEL FORMATION OF BETA-LACTOGLOBULIN - A STUDY ON THE SECONDARY AND TERTIARY STRUCTURE AS FOLLOWED BY CIRCULAR-DICHROISM SPECTROSCOPY
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 42 : 1650 1994
26. MOLINARI H
Partially folded structure of monomeric bovine beta-lactoglobulin
FEBS LETTERS 381 : 237 1996
27. NEET KE
CONFORMATIONAL STABILITY OF DIMERIC PROTEINS - QUANTITATIVE STUDIES BY EQUILIBRIUM DENATURATION
PROTEIN SCIENCE 3 : 2167 1994
28. OWUSU RK
THERMODYNAMIC ANALYSIS OF THE EFFECT OF CALCIUM ON BOVINE ALPHA-LACTALBUMIN CONFORMATIONAL STABILITY
FOOD CHEMISTRY 44 : 189 1992
29. OWUSU RK
THE EFFECT OF CALCIUM ON BOVINE ALPHA-LACTALBUMIN CONFORMATIONAL TRANSITIONS BY ULTRAVIOLET DIFFERENCE AND FLUORESCENCE SPECTROPHOTOMETRY
FOOD CHEMISTRY 43 : 41 1992
30. PACE CN
METHOD ENZYMOL 131 : 266 1986

Keywords

  • BOVINE ALPHA-LACTALBUMIN
  • NERVE GROWTH-FACTOR
  • THERMAL-DENATURATION
  • CONFORMATIONAL STABILITY
  • EQUILIBRIUM DENATURATION
  • ESCHERICHIA-COLI
  • GLOBULAR-PROTEINS
  • SELF-ASSOCIATION
  • SPECTROSCOPY
  • RESOLUTION

Fingerprint

Dive into the research topics of 'Beta-lactoglobulin denaturation by dissociation-coupled unfolding'. Together they form a unique fingerprint.

Cite this