Inactivation of pepsin and trypsin by deuteron and electron bombardment

Abstract 1. 1. The bombardment of dry pepsin and trypsin by deuterons causes a logarithmic inactivation fitting with random passage through a definite target. 2. 2. With allowance for the efficiency of the deuteron beam, the target size is in good agreement with that expected from the molecular weight. 3. 3. Electron bombardment of uncrystallized trypsin causes logarithmic inactivation fitting random inactivation in volume by primary ionization. 4. 4. This indicates that a single primary ionization in each molecule causes inactivation. If this proves to be general for enzymes it offers promise as an independent method of measuring molecular weight.