Kinetic study of site directed and randomly immobilized his-tag alkaline phosphatase by flow injection chemiluminescence.

We immobilized his-tag alkaline phosphatase (ALP) randomly and with the desirable orientation (site directed) to compare the effects of the enzyme activity on the beads. The chemiluminescence was employed to increase the sensitivity of enzyme labelled assays. Flow injection was also carried out for the detection of chemical and biological molecules in flow solutions. The Vmax of randomly immobilized his-tag ALP was 1.2 and the Vmax of site directed immobilized his-tag ALP was 1.5. In other words, the activity of site directed immobilized his-tag ALP was about 1.3-folds increased. The detection limit was detected to be 6 x 10(-6) M for the flow injection system.