Purification and characterisation of 1F-fructosyltransferase from the roots of asparagus (asparagus officinalis L.)

A fructosyltransferase that transfers a terminal d-fructosyl group from a (2→1)-β-linked fructosaccharide to HO-1 of another d-fructosyl group has been purified from an extract of asparagus roots by successive chromatography with DEAE-cellulose, octyl-Sepharose, Sephadex G-200, and raffinose-coupled Sepharose 6B. The disc-electrophoretically homogeneous enzyme was free from β-d-fructofuranosidase, sucrose:sucrose 1-fructosyltransferase, and 6^G-frutosyltransferase activity, and catalysed the d-fructosyl transfer from 1-kestose more rapidly to saccharides of the neokestose series [1^F(1-β-d-fructofuranosyl)_m-6^G(1-β-d-fructofuranosyl)_nsucrose] than to those of the 1-kestose series [1^F(1-β-d-fructofuranosyl)_nsucrose]. The enzyme was tentatively termed 1^F-fructosyltransferase. The general properties of the enzyme were as follows: mol. wt., ~64,000; optimum pH, ~5.0; stable at pH 5.0–5.5 at 45° for 20 min; stable at 30–45° for 10 min; inhibited by Hg²⁺, p-chloromercuribenzoate, and Ag⁺.