Real-time detection and quantification of adenosine triphosphate sulfurylase activity by a bioluminometric approach.

A real-time, sensitive, and simple assay for detection and quantification of adenosine triphosphate sulfurylase (ATP:sulfate adenylytransferase, EC 2.7.7.4) activity has been developed. The method is based on detection of ATP generated in the ATP sulfurylase reaction between APS and PPi by the firefly luciferase system. For the Saccharomyces cerevisiae ATP sulfurylase, the concentrations of APS and PPi at the half-maximal rate were found to be about 0.5 and 7 microM, respectively. The assay is sensitive and yields linear response between 0.1 microU and 50 mU. The method can be used for monitoring and quantification of recombinant ATP sulfurylase activity in Escherichia coli lysate, as well as for detection of the activity during different purification procedures.