Effect of phosphoric acid on a kinase assay - (Mar/14/2011 )

Hi all,

I am running some kinase assays. It contains my enzyme, a substrate and some ATP all in a physiological buffer. I am told my the manufacturer that i can halt the reaction by adding phosphoric acid to 0.06%. Can anyone explain exactly what is happening to the ATP in here? Is the acid sequestering the kinase ATP binding site, is there a shift in balance away from ATP to ADP because of the phosphoric acid?

Essentially i need to know the effect so i can determine if it will interferre with a downstream phosphatase reaction.

Biochemistry is not my thing, clearly - i've tried googling and various ewbsites explaining acids etc but have not got a suitable answer.

Any help from anyone would be most appreciated

I have no clue about this, but i would suggest you write to the supplier. If they know it will halt the reaction, they probably know how.

phosphate is usually a feedback inhibitor (product inhibition) of phosphatases, atpases, kinases and other enzymes that utilize atp.