... 3A) and ATP (Fig 3B) in the absence and presence of curcumin, using the coupled enzyme assay In Fig 3A, the half-maximal activation of the ATPase by Ca2þ was measured in the absence of and in the ... appear unlikely that curcumin can ‘occlude’ ATP binding, in the same way as chromium -ATP, by trapping the ATP in the binding site when the two domains come together [44], as our ATP binding data shows ... absence of ATP, curcumin is then able to bind to the ATPase (possibly at the hinge region) locking the two domains together and therefore precluding ATP binding (i.e inhibiting the ATPase in a ‘competitive...