title: Phosphorylation of different human milk proteins by human catalytic secretory immunoglobulin A.
abstract: The ability of secretory immunoglobulin A (slgA) from milk of healthy mothers to phosphorylate various milk proteins in the presence of gamma-[32P]-ATP was shown to be a property of the antibodies. The polyclonal slgA was purified by sequential chromatography on Protein-A Sepharose and DEAE-cellulose, and then separated by chromatography on the ATP-Sepharose. The preparations containing all milk proteins except for protein kinases [integrated milk proteins (IMP)] were obtained by extraction of the kinase activities from the milk using their affinity to the insoluble crosslinked staphylococcus. Addition of slgA fractions (having a different affinity to ATP) to the IMP led to phosphorylation of casein and several other milk proteins with different efficiencies.
authors.affiliation: Novosibirsk Institute of Bioorganic Chemistry, Academy of Sciences, Russia.
authors.lastname: Kit YYa
authors.forename: D V
authors.initials: DV
authors.lastname: Semenov
authors.forename: G A
authors.initials: GA
authors.lastname: Nevinsky
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D017151:Antibodies, Catalytic / Q000378:metabolism*; D002364:Caseins / Q000378:metabolism; D002846:Chromatography, Affinity; D002852:Chromatography, Ion Exchange; D003636:DEAE-Cellulose; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006801:Humans; D007071:Immunoglobulin A, Secretory / Q000302:isolation & purification / Q000494:pharmacology*; D008894:Milk Proteins / Q000378:metabolism*; D010766:Phosphorylation; D011494:Protein Kinases / Q000302:isolation & purification / Q000378:metabolism; D014357:Trypsin / Q000378:metabolism
chemical_list: D017151:Antibodies, Catalytic; D002364:Caseins; D007071:Immunoglobulin A, Secretory; D008894:Milk Proteins; D000255:Adenosine Triphosphate; D003636:DEAE-Cellulose; D011494:Protein Kinases; D014357:Trypsin