Temperature Controlled Activity of Lipase B from Candida Antarctica after Immobilization within p-NIPAM Microgel Particles

The immobilization of lipase B from Candida antarctica(CalB) within micronsized poly-N-Isopropylacrylamide (p-NIPAM) microgel particles with a crosslinker content of 5% is reported. The immobilization of the enzyme was reached by an exchange from polar to organic solvents. After determining the embedded amount of CalB within the polymer network, an enhanced specificactivity inn-hexane was obtained. Due to the thermoresponsibility of the polymer particles, the activity reaction was done at 25°C and 50°C. The results presented show that the reversiblecollapse of the microgel leads to a decreased activity with increasing temperature. Hence, p-NIPAMmicrogels display a good opportunity to tailor the activity of CalB. An interesting side effect is that CalB presents a suitable probe to estimate the mesh size of the polymer network, since itpenetrates in the unlabeled form but not after labeling with FITC