title: Esterase activity associated with secretory IgA and free secretory component preparations from human milk.
abstract: Secretory immunoglobulin A (IgA) and free secretory component were purified from human milk using methods involving (NH4)2SO4 precipitation, ion-exchange and gel-filtration chromatography. It was found that the preparations, although apparently pure by conventional criteria based on immunoelectrophoresis, zone electrophoresis, or ultracentrifugation, were consistently contaminated by two different esterases. These enzymes could apparently not be removed by further ion-exchange chromatography and/or gel filtration. They could, however, be eliminated by passage on an immunoabsorbent made from anti-free secretory component antiserum.
authors.affiliation: Department of Experimental Medicine, University of Louvain, Avenue Chapelle-aux-Champs 4 B-1200 Bruxelles, Belgium.
authors.forename: K
authors.initials: K
authors.lastname: Kobayashi
authors.forename: T K
authors.initials: TK
authors.lastname: Roberts
authors.forename: J P
authors.initials: JP
authors.lastname: Vaerman
authors.forename: P L
authors.initials: PL
authors.lastname: Masson
authors.forename: J F
authors.initials: JF
authors.lastname: Heremans
mesh_terms: D000327:Adsorption; D000818:Animals; D001671:Biochemistry / Q000379:methods*; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange / Q000379:methods; D004586:Electrophoresis / Q000379:methods; D004950:Esterases / Q000737:chemistry*; D006801:Humans; D007122:Immunoelectrophoresis / Q000379:methods; D007070:Immunoglobulin A / Q000737:chemistry*; D007071:Immunoglobulin A, Secretory / Q000737:chemistry* / Q000378:metabolism; D008895:Milk, Human / Q000378:metabolism*; D011817:Rabbits; D012635:Secretory Component / Q000378:metabolism; D014461:Ultracentrifugation / Q000379:methods
chemical_list: D007070:Immunoglobulin A; D007071:Immunoglobulin A, Secretory; D012635:Secretory Component; D004950:Esterases