Bovine beta-lactoglobulin was hydrolyzed with trypsin or chymotrypsin in the course of heat treatment at 55, 60 and 65 degrees C at neutral pH. At these temperatures beta-lactoglobulin undergoes significant but reversible structural changes. In the conditions used in the present study, beta-lactoglobulin was virtually insensitive to proteolysis by either enzyme at room temperature, but underwent extensive proteolysis when either protease was present during the heat treatment. High-temperature proteolysis occurs in a progressive manner. Mass spectrometry analysis of some large-sized breakdown intermediates formed in the early steps of hydrolysis indicated that both enzymes effectively hydrolyzed some regions of beta-lactoglobulin that were transiently exposed during the physical treatments and that were not accessible in the native protein. The immunochemical properties of the products of beta-lactoglobulin hydrolysis were assessed by using various beta-lactoglobulin-specific antibodies, and most epitopic sites were no longer present after attack of the partially unfolded protein by the two proteases.
|Titolo:||Proteolysis of bovine beta-lactoglobulin during thermal treatment in sub-denaturing conditions highlights some structural features of the temperature-modified protein and yields fragments with low immunoreactivity|
|Autori interni:||BONOMI, FRANCESCO (Ultimo)|
RASMUSSEN, PATRIZIA STELLA SKOV (Secondo)
IAMETTI, STEFANIA (Primo)
|Parole Chiave:||Bovine β-lactoglobulin; Limited proteolysis; Partial unfolding; Reduced immunoreactivity; Thermal treatment|
|Settore Scientifico Disciplinare:||Settore BIO/10 - Biochimica|
|Data di pubblicazione:||2002|
|Digital Object Identifier (DOI):||10.1046/j.1432-1033.2002.02769.x|
|Appare nelle tipologie:||01 - Articolo su periodico|
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