Molecular characteristics of sucrose synthase isolated from bird cherry leaves
Abstract
The molecular characteristics of partly purified sucrose synthase (NDP-glucose: D-fructose
2-α-D-glucosyltransferase, EC 2.4.1.13), extracted from the bird cherry (Prunus padus L.)
leaves was elucidated. The sucrose synthase was successfully purified by using a four-step
protocol including ammonium sulfate precipitation, dialysis, gel filtration on Sephadex
G-150 and ion-exchange chromatography with the use of DEAE -cellulose. The analysed enzyme
occurred in two isoforms (SuSyI and SuSyII ). The relative molecular weight of native
isoenzymes was estimated to be 200 and 180 kDa, respectively. Isoform SuSyI contained
two different subunits of 57.5 and 52.8 kDa, whereas the structure of SuSyII was consisted
of identical 63 kDa subunits. Experimental data indicated that the structure of both SuSy
isoforms was composed of three subunits.