title: Identification of the bovine alpha1-acid glycoprotein in colostrum and milk.
abstract: Alpha1-acid glycoprotein (AGP) is an immunomodulatory protein expressed by hepatocytes in response to the systemic reaction that follows tissue damage caused by inflammation, infection or trauma. This paper presents the detection of bovine AGP (boAGP) in mammary secretions (colostrum and milk) and mammary gland tissue. Bovine AGP was detected by Western blotting in all the samples analysed, and could be quantified in colostrum at 162 (+/- 63.7) microg/mL and 114.5 (+/- 67.8) microg/mL during the first 12 h and 24 h respectively. In mature milk, the boAGP concentration clearly decreased and was no longer detectable using the Radial Immunodiffusion (RID) technique. The concentration of mature milk boAGP was therefore semi-quantified using an anion-exchange chromatographic procedure that allowed the concentration of the protein to be determined. The presence of AGP in bovine milk was confirmed by the internal sequence analysis performed following purification to homogeneity of the protein from milk. The concentration of AGP in bovine milk with low SCC (< 250,000) was very similar to that from bovine milk with high SCC (> 250,000). In order to investigate the origin of AGP in bovine milk, a search for mRNA was carried out in somatic cells and mammary gland tissue: mRNA expression of the boAGP gene was detected in mammary gland tissue, but not in somatic cells. Finally, the cDNA sequence of the boAGP was determined, and is hereby presented.
authors.affiliation: Dipartimento di Patologia Animale, Igiene e Sanità Pubblica Veterinaria, University of Milan, via Celoria 10, 20133 Milano, Italy. fabrizio.ceciliani@unimi.it
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Ceciliani
authors.forename: Vanessa
authors.initials: V
authors.lastname: Pocacqua
authors.forename: Elena
authors.initials: E
authors.lastname: Provasi
authors.forename: Claudio
authors.initials: C
authors.lastname: Comunian
authors.forename: Alessandra
authors.initials: A
authors.lastname: Bertolini
authors.forename: Valerio
authors.initials: V
authors.lastname: Bronzo
authors.forename: Paolo
authors.initials: P
authors.lastname: Moroni
authors.forename: Paola
authors.initials: P
authors.lastname: Sartorelli
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002417:Cattle; D003126:Colostrum / Q000737:chemistry*; D004247:DNA; D005260:Female; D015870:Gene Expression; D008321:Mammary Glands, Animal / Q000378:metabolism; D008414:Mastitis, Bovine / Q000378:metabolism; D008892:Milk / Q000737:chemistry*; D008969:Molecular Sequence Data; D009961:Orosomucoid / Q000032:analysis*; D012333:RNA, Messenger; D017386:Sequence Homology, Amino Acid
chemical_list: D009961:Orosomucoid; D012333:RNA, Messenger; D004247:DNA