Regulation of the formation of proteinases inBacillus megaterium

The exocellular proteinases of asporogenic and sporogenicBacillus megaterium KM (megaterioproteinase A and S) were found to be active enzymes of the monomer type. The electrophoretic mobility of megaterioproteinase A is higher than that of S on acrylamide gel. After mixing, the enzymes could be separated again. The molecular weight of megaterioproteinase A was found to be 20,000–23,500, that of megaterioproteinase S 16,500–20,000 daltons, according to the “molecular sieving” method. The electrophoretic mobility of both proteinases was determined at different pH and the graphically calculated isoelectric point (pI) was found to be 7.3–7.4. The pK values of the ES complex estimated by plotting the logarithm of the maximum velocity of the enzymic reaction against pH were 6.0–6.1 and 7.8–8.0 for both megaterioproteinases. The activation energy was 13,500–13,600 for both enzymes. It is concluded that the above two enzymes resemble each other in enzymic properties but differ in electrophoretic mobility and probably also in molecular weight.