Continuous pH stat assay technique for glutamine and asparagine synthetase enzyme systems, involving ATP conversion to ADP plus Pi and AMP plus PPi, respectively

Glutamine synthetase and asparagine synthetase systems with reactions involving lysis of ATP to ADP and P_i or AMP and PP_i are usually assayed by discontinuous sampling and analysis or by coupled enzymic systems. Experimental results confirm theoretical predictions that such reactions may be continuously and directly monitored by pH stat devices. Sample volumes of 0.5–1.0 ml and buret volumes of 0.05–0.25 ml, with ATP levels near 1 mm can be used routinely. The number of enzyme reactions involving ATP to which this technique can be applied is quite large.