Kinetics and activity distribution of urease coencapsulated with hemoglobin within polyamide membranes

A 91.5% mass yield of urease and hemoglobin (Hb), co-encapsulated within polyamide membranes, was determined spectrophotometrically. The specific activity yield of microencapsulation was 84%, twofold higher than values previously reported, as a result of optimization of encapsulation conditions. The kinetic parameters and pH activity profiles of intracapsular urease were determined to be similar to those corresponding to the free enzyme. Similar activities were also observed for intact and microcapsule homogenate, indicating minimal mass transfer and diffusional limitation. The active configuration of the enzyme appears to remain intact upon microencapsulation. The application of a kinetic model for encapsulated urease further indicated that the kinetics were reaction-controlled with minimal mass transfer restrictions.