Irreversible inactivation of immobilized lipases by D-pNPP
Different lipase-immobilized preparations (1 g) were suspended in 10 mL of different
concentrations of sodium phosphate buffer (from 10 mM to 1 M) solution at
pH 7 and 25 ◦C. In some instances, 0.01% of detergent was added (see above). Then,
D-pNPP was added up to a concentration of 1 mM [52]. Samples of this suspension
were withdrawn periodically, and their activities were checked using the p-NPB
assay.