Effect of polymer matrix on thermal stability of immobilised trypsin

Abstract

AbstractTrypsin was markedly stabilised through immobilisation by radiation polymerisation of various monomers at low temperatures. A porous polymer matrix having a defined structure and flexibility enhanced the thermal stability. In highly hydrophilic monomer systems the resulting polymer matrix had a porous internal structure in which enzyme molecules were trapped. Trypsin was then protected from thermal denaturation and self‐autolysis. In contrast, polymers formed from hydrophobic monomers were of particle form and enzyme molecules were only trapped on the surface. With high concentrations of up to 90% monomer, the resulting radiation‐polymerised enzyme composites experienced limitations of substrate diffusion. There was an optimum hydrophilicity for enhancement of thermal stability of trypsin and this was found when the measured degree of hydration of the system was at a ratio of 0.35.