Biochem/physiol Actions P2X purinoceptor agonist similar in reactivity to ATP. Linkage 8-Bromo form of adenosine 5′-triphosphate. Application 8-Bromoadenosine 5′-triphosphate (8-Br-ATP) is as an ATP analogue used in conjunction with other ATP analogues to study and resolve ATP-site binding effects on receptor and enzyme function and specificity.