title: Differential protein composition of bovine whey: a comparison of whey from healthy animals and from those with clinical mastitis.
abstract: During clinical mastitis in dairy cows, the quantity of milk produced decreases and the composition of the milk is altered. As the severity of inflammation associated with the disease increases, the chemical composition of milk approaches that of blood as a consequence of increased permeability of the blood mammary barrier, or de novo intramammary synthesis, as has been suggested for mammary associated serum amyloid A3. A better understanding of these events may provide new approaches for the diagnosis and treatment of mastitis. The objective of this study was to document the changes in the protein composition of milk during clinical mastitis using a proteomic approach, with the objective of identifying new diagnostic markers of mastitis. Whey from dairy cows with clinical mastitis was compared to whey from healthy animals by two-dimensional gel electrophoresis (2-DE) with colloidal Coomassie staining and matrix-assisted desorption/ionization mass spectrometry. Increases in the concentrations of proteins of blood serum origin, including serotransferrin and albumin, were identified in mastitic whey compared to normal whey, while concentrations of the major whey proteins alpha-lactalbumin and beta-lactoglobulin were reduced in mastitic whey. Mass spectrometry subsequently confirmed the location of albumin, alpha-lactalbumin and beta-lactoglobulin on the 2-DE gels at M(r)/pI of 69 294/5.8, 14 200/4.5 and 19 883/4.9 respectively.
authors.affiliation: Department of Veterinary Clinical Studies, Centre for Integrated Diagnostic Systems, University of Glasgow, Thomson Building, Gilmorehill, Glasgow G12 8QQ, Scotland, UK.
authors.forename: Caroline J
authors.initials: CJ
authors.lastname: Hogarth
authors.forename: Julie L
authors.initials: JL
authors.lastname: Fitzpatrick
authors.forename: Andrea M
authors.initials: AM
authors.lastname: Nolan
authors.forename: Fiona J
authors.initials: FJ
authors.lastname: Young
authors.forename: Andrew
authors.initials: A
authors.lastname: Pitt
authors.forename: P David
authors.initials: PD
authors.lastname: Eckersall
mesh_terms: D000818:Animals; D002417:Cattle; D004396:Coloring Agents / Q000494:pharmacology; D019992:Databases as Topic; D015180:Electrophoresis, Gel, Two-Dimensional; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D007249:Inflammation; D013058:Mass Spectrometry; D008413:Mastitis / Q000378:metabolism*; D008894:Milk Proteins / Q000378:metabolism*; D010455:Peptides / Q000737:chemistry; D011506:Proteins / Q000737:chemistry; D012394:Rosaniline Dyes / Q000494:pharmacology; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D000067816:Whey Proteins
chemical_list: D004396:Coloring Agents; D008894:Milk Proteins; D010455:Peptides; D011506:Proteins; D012394:Rosaniline Dyes; D000067816:Whey Proteins; C048139:Coomassie blue