PARTIAL-PURIFICATION AND MODULATION OF TETRAHYDROBERBERINE OXIDASE FROM COSCINIUM-FENESTRATUM

Tetrahydroberberine oxidase, the enzyme involved in the final step of berberine biosynthesis, was partially purified from the plant tissue a nd cell cultures of Coscinium fenestratum (wood turmeric). Its kinetic s and effects of certain modulators such as metallic ions, co-factors and chelators were studied. The kinetic studies indicated that the K-m value of the enzyme is 1 x 10(-6) M. Among the different modulators s tudied, only CuSO4 showed enhancement in the enzyme activity. THB oxid ase activity was shown to be higher in 'production medium' optimised f or berberine production when compared to that in the growth medium. Su pplementation of copper sulphate in the production medium also showed increased activity of the enzyme along with increase in berberine prod uction compared to that of the control.