a radioiodinated photoaffinity analogue of methotrexate , n alpha- ( 4-amino-4-deoxy-10-methyl-pteroyl ) -n epsilon- ( 4-azidosalicylyl ) -l- lysine ( apa-asa-lys ) , was recently used to identify the plasma membrane derived binding protein involved in the transport of this folate antagonist into murine l1210 cells [ price , e. m. , & freisheim , j. h. ( 1987 ) biochemistry 26 , 4757-4763 ] .
C0007603
plasma membrane
C0007634
cells