title: Binding of aminocyclitol antibiotics to kidney and intestinal brush border membranes.
abstract: Binding of aminocyclitol antibiotics to intestinal and kidney brush border membranes has been studied in vitro by means of vesicular preparations. The binding is rapid, reversible, specific, saturable and has a high affinity. To both tissues, gentamicin and sisomicin bind to a single binding site or receptor. These antibiotics demonstrate increased binding under conditions of increasing pH. Membrane binding disappears when the vesicle proteins are denatured with TCA. A significant reduction in aminocyclitol binding after treatment of vesicles with papain indicates that a portion of the binding receptor protein is exposed to the outer surface of the brush border membrane. The accumulated evidence suggests that the nature of the binding mechanism is not a simple electrostatic interaction between the antibiotic's charged amino groups and the polyanions of the membrane. Alternatively, a specific membrane structure is required for binding whose characteristics reflect a drug-receptor interaction. Receptor binding is characterized as being saturable, reversible, and specific; all of which have been demonstrated for aminocyclitols and brush border membranes.
mesh_terms: D000818:Animals; D001692:Biological Transport; D002118:Calcium / Q000494:pharmacology; D002462:Cell Membrane / Q000378:metabolism*; D005839:Gentamicins / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D007413:Intestinal Mucosa / Q000378:metabolism*; D007477:Ions; D007668:Kidney / Q000378:metabolism*; D008297:Male; D008871:Microvilli / Q000378:metabolism*; D010206:Papain / Q000494:pharmacology; D011817:Rabbits; D012853:Sisomicin / Q000378:metabolism*
chemical_list: D005839:Gentamicins; D007477:Ions; D010206:Papain; D002118:Calcium; D012853:Sisomicin