Abstract
Thermal treatment of milk leads to non-enzymatic glycosylation of proteins through Maillard reaction. Free NH2 groups of basic amino acids react with the reducing carbonyl group of lactose forming the so-called Amadori products. Electrospray mass spectrometry analysis shows that β-lactoglobulin (β-LG), the major whey protein, undergoes lactosylation under industrial thermal treatment. In order to investigate the specificity of reactive sites for lactose binding the analysis of trypsin hydrolysates of β-LG isolated from different industrial milks was performed. Results demonstrate that Lys-100 is a preferential lactosylation site of β-LG during industrial milk treatment. These results were confirmed by an analysis of the three-dimensional model of the protein which showed that Lys-100 had the highest solvent accessibility and proximity to another amino group making Lys-100 the best candidate to lactosylation. Lys-47, previously identified by other authors, showed a good proximity to another Lys residue, but an intermediate level of exposition to solvent. Copyright (C) 1998 Elsevier Science B.V.
Original language | English |
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Pages (from-to) | 295-304 |
Number of pages | 10 |
Journal | Biochimica et Biophysica Acta - Protein Structure and Molecular Enzymology |
Volume | 1388 |
Issue number | 2 |
DOIs | |
Publication status | Published - 10 Nov 1998 |
Externally published | Yes |
Keywords
- β-Lactoglobulin
- Amadori compound
- Glycosylation
- Lactosylation
- Liquid chromatography-mass spectrometry
- Maillard reaction
- Milk
- Thermal treatment