• Decrease font size
  • Return font size to normal
  • Increase font size
U.S. Department of Health and Human Services

CVM Publications - Detail

  • Print
  • Share
  • E-mail
TITLE:  Proteomic analysis of differentially expressed proteins in bovine milk during experimentally induced Escherichia coli mastitis
AUTHORS:  Boehmer JL;Bannerman DD;Shefcheck K;Ward JL;
YEAR:  2008
JOURNAL FULL:  Journal of dairy science
ISSUE:  11
END PAGE:  4218
KEYWORDS:  analysis;Animals;Cattle;chemistry;Electrophoresis,Gel,Two-Dimensional;Escherichia coli;Escherichia coli Infections;Female;Food;Gene Expression Profiling;Gene Expression Regulation;Mass Spectrometry;Mastitis,Bovine;metabolism;methods;microbiology;Milk;Milk Proteins;Orosomucoid;Proteins;Proteomics;Serum Albumin;veterinary;Veterinary Medicine;
ABSTRACT:  The objectives of the current study were to profile changes in protein composition using 2-dimensional gel electrophoresis on whey samples from a group of 8 cows before and 18 h after infection with Escherichia coli and to identify differentially expressed milk proteins by peptide sequencing using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry post source decay. Only proteins present in whey fractions of all 8 cows were sequenced to avoid reporting a protein response unique to only a subset of infected cows. Despite the overwhelming presence of casein and beta-lactoglobulin, the low abundance proteins transthyretin, lactadherin, beta-2-microglobulin precursor, alpha-1-acid glycoprotein, and complement C3 precursor could be identified in whey samples from healthy cows. Whey samples at 18 h postinfection were characterized by an abundance of serum albumin, in spots of varying mass and isoelectric point, as well as increased transthyretin and complement C3 precursor levels. Also detected at 18 h postinoculation were the antimicrobial peptides cathelicidin, indolicidin, and bactenecin 5 and 7, and the proteins beta-fibrinogen, alpha-2-HS-glycoprotein, S100-A12, and alpha-1-antiproteinase. Most notable was the detection of the acute phase protein alpha-1-acid glycoprotein in mastitic whey samples, a result not previously reported. In contrast to methods used in previous proteomic analyses of bovine milk, the methods used in the current study enabled the rapid identification of milk proteins with minimal sample preparation. Use of a larger sample size than previous analyses also allowed for more robust protein identification. Results indicate that examination of the protein profile of whey samples from cows after inoculation with E. coli could provide a rapid survey of milk protein modulation during coliform mastitis and aid in the identification of biomarkers of this disease
AFFILIATIONS:  US Food and Drug Administration Center for Veterinary Medicine, Laurel, MD 20708, USA. jamie.boehmer@fda.hhs.gov