Copper modulates the heat-induced sulfhydryl/disulfide interchange reactions of beta-Lactoglobulin - INRAE - Institut national de recherche pour l’agriculture, l’alimentation et l’environnement Accéder directement au contenu
Article Dans Une Revue Food Chemistry Année : 2009

Copper modulates the heat-induced sulfhydryl/disulfide interchange reactions of beta-Lactoglobulin

M. Gulzar
  • Fonction : Auteur
Julien Jardin
M. Piot
  • Fonction : Auteur
Said Bouhallab

Résumé

This study describes the effect of copper on the heat-denaturation/aggregation of beta-Lactoglobulin AB at neutral pH. The kinetics of disappearance of native beta-Lactoglobulin under different ionic strength and Cu(2+)/beta-Lactoglobulin molar ratio conditions were followed and the type of interactions (covalent or non-covalent) shared between non-native structures during the heating process were examined. On heating, the rate of disappearance of native beta-Lactoglobulin was accelerated by increasing the Cu(2+)/beta-Lactoglobulin molar ratio. Copper induces oxidation of the free sulfhydryl group of beta-Lactoglobulin resulting mainly in the formation of covalent dimers, which were further associated into large non-covalent aggregates under high ionic strength conditions. Characterisation of the beta-Lactoglobulin dimers reveals the existence of three different molecular species arising randomly (dimers A-A, A-B and B-B), in which tertiary structure was completely lost. The quantity of added copper constitutes a powerful way to control the heat-denaturation/aggregation process of beta-Lactoglobulin in particular regarding the relative proportion of covalent and non-covalent interactions into formed aggregates.

Dates et versions

hal-00729989 , version 1 (07-09-2012)

Identifiants

Citer

M. Gulzar, Thomas Croguennec, Julien Jardin, M. Piot, Said Bouhallab. Copper modulates the heat-induced sulfhydryl/disulfide interchange reactions of beta-Lactoglobulin. Food Chemistry, 2009, 116 (4), pp.884-891. ⟨10.1016/j.foodchem.2009.03.043⟩. ⟨hal-00729989⟩
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