PURIFICATION, CHARACTERIZATION, AND PRODUCTION OF 2 PECTIC TRANSELIMINASES WITH PROTOPECTINASE ACTIVITY FROM BACILLUS-SUBTILIS

We found two enzymes that solubilize pectin from protopectin, tentativ ely named protopectinase-N (PPase-N) and protopectinase-R (PPase-R), i n a culture filtrate of Bacillus subtilis IFO 3134. These enzymes were purified to homogeneity by hydrophobic, cation:exchange and size excl usion chromatographies. The molecular weights of PPase-N and PPase-R w ere estimated to be 43,000 and 35,000, respectively, by SDS-PAGE. Thei r pls were 9.4 and 8.2, respectively. These enzymes were stable in a w ide range of pH and temperature. PPase-N and -R released water-soluble pectin by transeliminative cleavage of protopectin. According to thei r substrate specificities and modes of action, PPase-N and PPase-R cou ld be classified as endo-pectate transeliminase (pectate lyase; EC 4.2 .2.2) and endo-pectin transeliminase (pectin lyase; EC 4.2.2.10), resp ectively. Both enzymes were produced in a simple medium containing def atted soybean flour and phosphates. Production of PPase-N was represse d by addition of glucose while that of PPase-R was enhanced by phospha te.