Interaction between .kappa.-casein and .beta.-lactoglobulin: possible mechanism

Role of Whey Protein-Casein Complexes on Yoghurt Texture

“…An early stage of heating, denatured -lactoglobulin interact with -casein via both hydrophobic and S-S interactions but this interactions depend on the protein systems and heating temperature as well as heating time (Cho et al, 2003). This agreement is supported by Haque et al (1987), who reported that the interactions between -lactoglobulin and -casein occurs through hydrophobic attractions at early stage and after that covalent bond is formed via -SH/S-S interchange reactions. Furthermore, -lactalbumin participates to make complex with -casein after formation of -lactoglobulin--lactalbumin complex because of unavailable free reactive -SH group containing in -lactalbumin (Anema, 2009).…”

Interactions betweenk-Casein andβ-Lactoglobulin: Effects of Anions on Covalent Stabilization of the Complex

“…6 ) The Hofmeister, lyotropic or chaotropic series of anions have been used to observe the contribution of hydrophobic forces in proteilljprotein interaction,7-9) and the possible effects of high concentrations (> 0.1 M) of these anions on disruption of the water structure around apolar amino acid residues, following the order of -SCN -> -Cl-> -SO,;, has been reported. 9 .…”

Interaction betweenk-Casein andβ-Lactoglobulin: Effect of Calcium

“…10 ) The binding .of Ca2+ t.o the K-CjB-Lg mixture during the heat treament was determined by flu.orescence spectr.oph.otometry using Quin-2 11 ) as a flu.orescent pr.obe. The flu.orescence .of Quin-2 decreases st.oichi.ometrically as free Ca2+ is depleted fr.om the system.…”

“…Under similar conditions, the A3 complex comprised only 27% after heating for 120 s in the presence of EGTA. 5 ) Calcium is adsorbed by both proteins, but this is dependent on the degree ofimfolding and exposure of base titratable residues and that Ca 2 + greatly enhances the formation of A3 (Figs. I and 2).…”

“…However, it should be noted that the A3 is less reactive with K-C as to formation of the K-CfB-Lg A4 complex compared to a spontaneous reaction in the presence of.EGTA. 5 ) .…”