Chaperone-like activity of β-casein and thermal stability of alcohol dehydrogenase

Abstract

To elucidate the correlation of structural peculiarities of beta-casein and their chaperon-like activity the modified forms of the protein (with cysteinyl residues introduced in polypeptide chain) were investigated. The aggregation of native and recombinant beta-caseins was studied as well as their chaperon-like activity towards alcohol dehydrogenase thermal aggregation. It was shown that physico-chemical and chaperone-like properties ofdimeric and oligomeric forms ofbeta-casein (which formation is due to intermolecular disulfide bonds) differ significantly from monomeric forms. It was found that thermal stability of alcohol dehydrogenase depends on beta-casein concentration.

Controlling heat induced aggregation of whey proteins by casein inclusion in concentrated protein dispersions

“…The a S -and b-caseins in a pure dispersion can assemble into micellar forms, with its size influenced by temperature (Zakharchenko et al, 2012), accompanied by concurrent increase of the hydrophobicity. It has been proposed that their chaperon like effect is manifested through formation of hydrophobically driven complexes with the substrate proteins (Bhattacharyya & Das, 1999;Zhang et al, 2005) or formation of micelles encompassing the unfolded substrate proteins (Kehoe & Foegeding, 2011).…”

Chaperone‐like activity of β‐casein and its effect on residual in vitro activity of horseradish peroxidase

“…there seem to be a plateau of saturation and adding more β‐casein seemed not to increase further residual activity. This saturation effect has been reported before in the literature for studies with alcohol dehydrogenase (Zakharchenko et al ., ) and carbonic anhydrase (Khodarahmi et al ., ).…”

How to Quantify the Chaperone-Like (Anti-Aggregation) Activity?

“…In works [32,34,35] the k I A lim product was used for the quantitative characterization of the chaperone-like activity of whole casein and βcasein. It is of interest that the k I A lim value versus [whole casein] plot for suppression of aggregation accompanying renaturation of denatured carbonic anhydrase by whole casein looks like a curve consisting of two linear parts [32].…”