Application of proteomic techniques to protein and peptide profiling of Teleme cheese made from different types of milk

Water-soluble extracts of Teleme cheeses prepared from sheep, goat or cow milk and matured 120 days have been analysed for constituent peptides and proteins using proteomics. Techniques used include: (a) two-dimensional gel electrophoresis, with matrix-assisted laser desorption ionisation/mass spectrometry, (b) high-performance liquid chromatography in conjunction with mass spectrometry and Edman degradation and (c) tandem mass spectrometry. Gel electrophoresis showed species-specific differences in whey proteins and peptides from caseins but differences could not be resolved unambiguously using available databases. From high-performance liquid chromatography individual peaks were shown to be composed of a spectrum of peptides, with α-lactalbumin, β-lactoglobulin and a spectrum of casein-derived peptides most abundant. Tandem mass spectrometry detected casein-derived peptides with mass range 3000–1500 Da and identified species-specific differences. Overall, the peptide profile for Teleme cheese is typical of other cheeses and the species milk source can be resolved through proteomics.