Effect of methotrexate on folate binding to a folate binding protein in cow's milk.
Folate in cow's milk was strongly bound to a minor whey protein. Methotrexate inhibited the folate binding in a log dosis dependent manner, but was a rather weak inhibitor. The binding mechanism of folate changed from a cooperative to a non-cooperative type in the presence of methotrexate. This model system could be used in investigations on human body fluids and tissues.
D000818:Animals; D002417:Cattle; D004305:Dose-Response Relationship, Drug; D005492:Folic Acid / Q000378:metabolism*; D066298:In Vitro Techniques; D008727:Methotrexate / Q000494:pharmacology*; D008894:Milk Proteins / Q000378:metabolism*; D011485:Protein Binding / Q000187:drug effects*
D008894:Milk Proteins; D005492:Folic Acid; D008727:Methotrexate