ATPase assay

The ATPase assay is designed to indicate the nature of the interaction between the compound and the transporter. The ATPase assays are used in two different modes: ATPase activation and ATPase inhibition. Transported substrates increase baseline ATPase activity, while inhibitors or slowly transported compounds inhibit baseline ATPase activity and/or the ATPase activity measured in the presence of a stimulating agent. The ATPase assays can therefore have the potential for determining whether a compound acts as a transporter substrate and/or inhibitor.^[2][3]

Mutations in the ATPase domain result in loss of transport function. The activity of the multidrug transporter in drug-resistant cells is associated with rapid cellular ATP depletion when ATP synthesis is inhibited.