PURIFICATION AND SOME PROPERTIES OF FRUCTAN-FRUCTAN FRUCTOSYL TRANSFERASE FROM DANDELION (TARAXACUM-OFFICINALE WEBER)

A fructan: fructan fructosyl transferase (FFT, EC 2.4. 1.100) was purified 61.4-fold from roots of Taraxacum officinale Weber. The enzyme is a glycoprotein with an apparent molecular weight of 49000 as determined by SDS-polyacrylamide gel electrophoresis. FFT activity was detected by 1 -kestose-dependent nystose production. The enzyme was most active at pH 6.5 and was stable at 30-degrees-C (1 h). Separation by preparative iso-electric focusing yielded four different forms with iso-electric points around pH 4.8. The purified enzyme was active on different oligofructans of the inulin series, but not on melezitose, 6-kestose, neokestose, maltopentaose or sucrose as the sole substrate.