PURIFICATION AND SOME PROPERTIES OF THE ENZYME CATALYZING THE C-GAMMA-ELIMINATION OF A DIARYLPROPANE-TYPE LIGNIN MODEL FROM PSEUDOMONAS-PAUCIMOBILIS TMY1009

A novel enzyme catalyzing the C-gamma-elimination of a diarylpropane-type lignin model, erythro-1,2-bis(4-hydroxy-3-methoxyphenyl)-propane-1,3-diol, was purified from a cell-free extract of Pseudomonas paucimobilis TMY 1009. When the diarylpropane was decomposed by the purified enzyme, equimolar amounts of 1,2-bis(4-hydroxy-3-methoxyphenyl)-ethylene and formaldehyde were produced as reaction products, suggesting that the enzymatic reaction is C-gamma-deformylation accompanied with dehydroxylation at the C-alpha-position. Consequently, this enzyme was designated tentatively as diarylpropane formaldehyde lyase. The optimum pH for the enzyme activity was around 7.5 and the Km value for the diarylpropane was 71-mu-M. This enzyme was seemed to be composed of two identical subunits and the molecular weight of the native enzyme was estimated to be 80,000.