Alternative molecular interpretations of binding curves: compelling competition?

Abstract A drug which increases the K d of a radioligand without altering its B max has a competitive interaction with the receptors. Although such data occur most commonly in simple situations in which the drug and radioligand bind reversibly to a common binding site without altering the receptors in other ways, Antonio DeBlasi and Harvey Motulsky point out that similar data can also be obtained in more complicated situations.