Abstract
Some physicochemical properties and substrate specificities of acid proteases A-1 and A-2 isolated from Scytalidium lignicolumn were studied. A-1 and A-2 were very similar to each other except for a small difference in isoelectric point (A-1; pI=3.6, A-2; pI=3.8). The molecular weights of both enzymes were 40, 000 by the sedimentation equilibrium method. These enzymes contained no histidine residue, similarly to acid protease B of S. lignicolumn. Both the enzymes were glycoprotein, containing 3 moles of glucosamine and 10_??_15 moles of mannose.
Substrate specificities of A-1 and A-2 against various synthetic peptides were different from other acid proteases which were inactivated by S-PI, DAN, and EPNP.
