STRUCTURAL AND ENZYMATIC COMPARISON OF LIGNOSTILBENE-ALPHA,BETA-DIOXYGENASE ISOZYMES, I, II, AND III, FROM PSEUDOMONAS-PAUCIMOBILIS TMY1009

Three isozymes of lignostilbene-alpha,beta-dioxygenase (LSD) from Pseu domonas paucimobilis TMY1009 were separated on QAE-Toyopearl chromatog raphy. All active fractions were further chromatographed on DEAE-Toyop earl, Butyl-Toyopearl, and Sephacryl S-300 columns. Then the isozymes I, II, and III were purified homogeneously. All three isozymes consist ed of two subunits with the same mol. mass. According to the N-termina l amino acid sequences up to 25 residues of these three isozymes and t he reversed-phase HPLC patterns of peptidase-digested them, it was fou nd that LSD-I, II, and III consisted of alphaalpha, alphabeta, and bet abeta subunits, respectively. They showed different specificities for several substrates that are stilbene and styrene derivatives.