Preparation and Properties of Carrier‐Bound Enzymes

Proteases from animal, plant and microbial origin have been made insoluble by covalent attachment to two hydrophilic carriers, a highly substituted carboxymethyl‐cellulose and a cross‐linked copolymer of maleic anhydride and butanediol divinylether. Stable preparations with protein contents of 20–40% and with enzymatic activities on low molecular weight substrates up to 90% (compared to the soluble enzymes) have been obtained. Carrier‐bound enzymes show considerable less heat inactivation than soluble enzymes. Employed batchwise or in columns the bound enzymes can be reused many times with only slight loss of activity. The activity of the bound enzymes is dependent on the charge and the molecular weight of the substrates used due to charge interaction with the negatively charged matrices and steric restrictions. This effect has been studied for trypsin and proteinase K bound to CM‐cellulose acting on various substrates of different charge and molecular weight. Some possibilities for application of these carrier‐bound enzymes are discussed.