engleski

A potentnial high-throughput method for the determination of lipase activity by potentiometric flow injection titrations

Potentiometric FIA titrations were performed to determine enzyme activities of lipase type B from Candida antarctica, CAL.B. Two substrates, triacetin and tributyrin were hydrolyzed in phosphate buffer solutions, and the concentration change of the base component of the buffer was titrated in a carrier solution containing acid and potassium chloride. The system was calibated with butyric acid, respectivily. FIA titration peaks were evaluated with respect to pek high and peak area. Butyric acid and acetic acid could be titrated in the buffer solution from 3 x 10-3 molL-1 to 0.1 moljL-1. The detection limit enzyme activiti was determined to be 0.07 UmL-1 (15 min reaction time) and the minimum activity was calculated to be 0.035 units corresponding to 35 nmolmin-1. The specific acitivities of lipase B for the hydolysis of tributyrin and triacetin were determined as 16 +- 2 U mg-1 and 2 +- 0.2 U mg-1 (per mg commercial lipase preparation), respectively.

titrations ; high-throughput screening ; lipase activity ; composite pH-detector

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