Characterization of lactoferrin binding to the MAC-T bovine mammary epithelial cell line using a biotin-avidin technique

Abstract

1. 1. A non-radioisotopic method utilizing a biotin-avidin approach was used to characterize lactoferrin binding to the clonal MAC-T bovine mammary epithelial cell line. 2. 2. Binding of lactoferrin to MAC-T cells and isolated membranes was specific and saturable. 3. 3. Unlabeled lactoferrin competed for and displaced biotin-labeled lactoferrin from binding sites on mammary epithelial cells. In contrast, unlabeled transferrin did not compete. 4. 4. Scatchard analysis of lactoferrin binding to MAC-T cell crude membranes was nonlinear, revealing two classes of binding sites with association constants ( K a ) of 2.36 × 10 7 and 3.36 × 10 6M −1. 5. 5. Binding of lactoferrin to MAC-T cells may be associated with the initial events which result in decreased MAC-T cell proliferation.