Two-dimensional gel electrophoresis/matrix-assisted laser desorption/ionisation mass spectrometry of commercial bovine milk.
Proteins in commercial bovine milk have been separated by two-dimensional gel electrophoresis and examined by matrix-assisted laser desorption/ionisation mass spectrometry. Gel separation was conducted in two different pH gradients, 3-10 and 6-11; the latter range resulted in a higher spot resolution and favoured the basic proteins. We have limited the time-of-flight mass spectrometry analysis to the linear mode to examine the capability of reliable relative molecular masses of the intact proteins in their characterisation. The present study draws attention to the difficulty of identifying basic proteins with low molecular masses (below 12000 Da) that are commonly encountered in milk samples.
Glaxo Wellcome Medicines Research Center, via Fleming 4, Verona, Italy.
M
M
Galvani
M
M
Hamdan
P G
PG
Righetti
D000818:Animals; D002364:Caseins / Q000737:chemistry / Q000302:isolation & purification; D002417:Cattle; D015180:Electrophoresis, Gel, Two-Dimensional / Q000379:methods; D005260:Female; D008892:Milk / Q000737:chemistry*; D008894:Milk Proteins / Q000737:chemistry* / Q000302:isolation & purification*; D008970:Molecular Weight; D010766:Phosphorylation; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods
D002364:Caseins; D008894:Milk Proteins