title: Preparation and comparison of cytotoxic complexes formed between oleic acid and either bovine or human α-lactalbumin.
abstract: α-Lactalbumin is a ubiquitous calcium-binding milk protein with a well-characterized function in regulating the synthesis of lactose. An entirely different activity has been shown to occur when a complex is formed between calcium-free α-lactalbumin and oleic acid. This complex shows strong cytotoxic action against several cancer cells, and several mechanisms have been suggested to account for this cell-killing activity. Most studies have been performed using the human protein, but bovine α-lactalbumin shows similar activity. A new and simple 2-step method for purification of calcium-free α-lactalbumin has been developed, and the resulting highly purified preparation was used to generate a complex with oleic acid. Using 3 different cell lines and 2 types of cell viability assays, the bovine and human α-lactalbumin showed comparable cytotoxic activity. The effect was apparent after 15 min of incubation and was inhibited by the presence of fetal bovine serum or bovine serum albumin. The bovine protein might be a useful alternative to the human protein, but also raises the question whether cytotoxic activity could be generated in different kinds of food containing α-lactalbumin.
authors.affiliation: The Protein Chemistry Laboratory, Department of Molecular Biology, Aarhus University, Science Park, Gustav Wieds Vej 10, DK-8000 Aarhus C, Denmark.
authors.forename: C R
authors.initials: CR
authors.lastname: Brinkmann
authors.forename: S
authors.initials: S
authors.lastname: Thiel
authors.forename: M K
authors.initials: MK
authors.lastname: Larsen
authors.forename: T E
authors.initials: TE
authors.lastname: Petersen
authors.forename: J C
authors.initials: JC
authors.lastname: Jensenius
authors.forename: C W
authors.initials: CW
authors.lastname: Heegaard
mesh_terms: D000818:Animals; D002417:Cattle; D002452:Cell Count; D045744:Cell Line, Tumor / Q000187:drug effects; D016895:Culture Media, Serum-Free; D003603:Cytotoxins / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D018922:HL-60 Cells / Q000187:drug effects; D006801:Humans; D007768:Lactalbumin / Q000138:chemical synthesis / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D008892:Milk / Q000737:chemistry*; D008895:Milk, Human / Q000737:chemistry*; D019301:Oleic Acid / Q000032:analysis / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D009829:Oleic Acids / Q000138:chemical synthesis / Q000494:pharmacology*; D044967:Serum; D020298:U937 Cells / Q000187:drug effects
chemical_list: C560443:BAMLET complex, Bos taurus; D016895:Culture Media, Serum-Free; D003603:Cytotoxins; C506422:HAMLET complex, human; D009829:Oleic Acids; D019301:Oleic Acid; D007768:Lactalbumin