Structure of the enzymatically synthesized fructan inulin

Construction, purification and characterization of a fusion protein of malt ose-binding protein of Escherichia coli and the fructosyltransferase of Str eptococcus mutans is described. With the purified protein, in vitro synthes is of inulin was performed. The obtained polysaccharide was characterized b y high-performance size-exclusion chromatography (HPSEC) and static light s cattering (SLS) in dilute aqueous and dimethyl sulfoxide solution. For all samples very high molecular weights between 60 x 10(6) and 90 x 10(6) g/mol and a remarkable small polydispersity index of 1.1 have been determined. S mall root-mean-square radii of gyration point to a compact conformation in dilute solution. No difference between native and enzymatically synthesized inulin was observed by X-ray powder diffraction and thermoanalysis of soli d samples. (C) 1998 Elsevier Science Ltd. All rights reserved.