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

Abstract

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 Hg 2+, p-chloromercuribenzoate, and Ag +.