Evaluation of a sulphydryl-disulphide exchange index (SEI) for whey proteins - beta-lactoglobulin and bovine serum albumin

Richard Owusu-Apenten, C Chee, OP Hwee

Research output: Contribution to journalArticlepeer-review

21 Citations (Scopus)

Abstract

Sulphydryl-disulphide (SH-SS) exchange underlies many protein functions in processed foods. There is a need for reliable indicators of SH-SS exchange capacity in protein ingredients. An index for SH-SS exchange (SEI) is described using beta-lactoglobulin (BLG) or bovine serum albumin (BSA). The proteins were reacted with 2-pyridine disulphide (PDS Aldrithiol-2(TM)) or Ellman's reagent (DTNB) in a buffered medium (0.05 M phosphate buffer, pH 6.9) at 25degreesC. The 2nd order rate constant for protein SH-SS exchange with PDS or DTNB (k, M-1 s(-1)) was normalized by dividing by the rate constant for glutathione (GSH) reaction with PDS or DTNB (k*, M-1 s(-1)) determined under identical conditions. The capacity or SH-SS exchange was inversely related to SEI (= -log k/k*) values of 4.11 for BLG and 1.05 for BSA, based on measurements using PDS. Studies using DTNB yield SEI equal to 4.28 for BLG and 2.20 for BSA. The SH group of BSA was 100-1052 times more reactive than the SH group of BLG. In a medium containing 1.2 M sodium chloride the difference in SH-SS exchange capacity was similar to9000 fold. Differential scanning calorimetry (DSC) results showed that the conformational stability of BLG increased much more substantially than BSA when both proteins were exposed to 0.1-1.2 M sodium chloride concentrations. (C) 2003 Elsevier Ltd. All rights reserved.
Original languageEnglish
Pages (from-to)541-545
JournalFood Chemistry
Volume83
Issue number4
DOIs
Publication statusPublished - Dec 2003

Bibliographical note

Reference text: 1. ANDREWS AT
20 INT DAIR C E 1978 162
2. 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
3. APENTEN RKO
Protein stability function relations: native beta-lactoglobulin sulphhydryl-disulphide exchange with PDS
JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 80 : 447 2000
4. BATRA PP
CIRCULAR DICHROIC STUDY OF THE CONFORMATIONAL STABILITY OF SULFHYDRYL-BLOCKED BOVINE SERUM-ALBUMIN
INTERNATIONAL JOURNAL OF BIOCHEMISTRY 21 : 857 1989
5. BROWNE KR
J CONT LEGAL ISSUES 8 : 5 1997
6. CALVO MM
INT DAIRY J 3 : 719 1993
7. CASPER JL
Seasonal changes in protein composition of whey from commercial manufacture of caprine and ovine specialty cheeses
JOURNAL OF DAIRY SCIENCE 81 : 3117 1998
8. FRIEDMAN M
CHEM BIOCH SULFHYDRY : 1973
9. HILL AR
THE BETA-LACTOGLOBULIN-KAPPA-CASEIN COMPLEX
CANADIAN INSTITUTE OF FOOD SCIENCE AND TECHNOLOGY JOURNAL-JOURNAL DE L INSTITUT CANADIEN DE SCIENCE ET TECHNOLOGIE ALIMENTAIRES 22 : 120 1989
10. HILLIER RM
GELATION OF RECONSTITUTED WHEY POWDERS BY HEAT
JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 31 : 1152 1980
11. HOWELL NK
INT J FOOD SCI TECH 30 : 311 1995
12. 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
13. LEE JY
EFFECT OF SALTS ON THE THIOL-DEPENDENT GELATION OF BOVINE SERUM-ALBUMIN
AGRICULTURAL AND BIOLOGICAL CHEMISTRY 55 : 2057 1991
14. MANNING PB
METHOD FOR DETERMINING SULFHYDRYL AND DISULFIDE GROUPS IN MILK PROTEINS
JOURNAL OF DAIRY SCIENCE 52 : 886 1969
15. MATSUDOMI N
GELATION OF BOVINE SERUM-ALBUMIN AND BETA-LACTOGLOBULIN - EFFECTS OF PH, SALTS AND THIOL REAGENTS
FOOD CHEMISTRY 40 : 55 1991
16. OWUSUAPENTEN RK
Revised conformational stability parameters for beta-lactoglobulin isothermal denaturation by urea
JOURNAL OF FOOD BIOCHEMISTRY 26 : 181 2002
17. RALSTON GB
DECREASE IN STABILITY OF BETA-LACTOGLOBULIN ON BLOCKING SULFHYDRYL GROUP
COMPTES RENDUS DES TRAVAUX DU LABORATOIRE CARLSBERG 38 : 499 1972
18. REINER CK
ANAL BIOANAL CHEM 373 : 266 2002
19. SAKAI K
Conformation and stability of thiol-modified bovine beta-lactoglobulin
PROTEIN SCIENCE 9 : 1719 2000
20. WALSTRA P
DAIRY TECHNOLOGY : 1990
21. WILSON JM
SPECTROPHOTOMETRIC METHOD FOR STUDYING THE RATES OF REACTION OF DISULFIDES WITH PROTEIN THIOL-GROUPS APPLIED TO BOVINE SERUM-ALBUMIN
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 102 : 359 1980
22. ZHANG H
A kinetic approach to characterize the electrostatic environments of thiol groups in proteins
BIOORGANIC CHEMISTRY 26 : 356 1998

Keywords

  • STABILITY FUNCTION RELATIONS
  • CONFORMATIONAL STABILITY
  • THIOL-GROUPS
  • GELATION
  • SALTS

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