Journal article
Proteolysis of bovine beta-lactoglobulin during thermal treatment in subdenaturing conditions highlights some structural features of the temperature-modified protein and yields fragments with low immunoreactivity
Bovine beta-lactoglobulin was hydrolyzed with trypsin or chymotrypsin in the course of heat treatment at 55, 60 and 65 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.
Language: | English |
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Year: | 2002 |
Pages: | 1362-1372 |
ISSN: | 14321033 and 00142956 |
Types: | Journal article |
DOI: | 10.1046/j.1432-1033.2002.02769.x |