Preparation, properties and substrate-exclusion effects of an insoluble pronase derivative.

1. A diazotized co-polymer of leucine and p-aminophenylalanine was used to prepare insoluble pronase. 2. The product was similar to the native enzyme in pH optimum, temperature optimum and broad specificity. 3. Exclusion effects were observed that appear related to the molecular weight of the substrate being hydrolysed. 4. The effects are explained on the basis of impedance of substrate access to the catalytic site by the supporting solid matrix.