Kinetic properties of an inulosucrase from Lactobacillus reuteri 121

• Published in: FEBS letters Vol. 534; no. 1; pp. 207 - 210
• Main Authors: van Hijum, S.A.F.T, van der Maarel, M.J.E.C, Dijkhuizen, L
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 16.01.2003
• Subjects: fructose; Fructosyltransferase; Hexosyltransferases - drug effects; Hexosyltransferases - genetics; Hexosyltransferases - metabolism; Hydrogen-Ion Concentration; Hydrolysis; inulin; Inulosucrase; Kinetics; Lactobacillus - enzymology; Lactobacillus reuteri; Metals - metabolism; Metals - pharmacology; Recombinant Proteins - genetics; Recombinant Proteins - metabolism; Sequence Deletion; Sucrose; Temperature; transferase; Fructosyltransferase; Lactobacillus reuteri; Sucrose; Inulosucrase
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/S0014-5793(02)03841-3

Inulosucrases catalyze transfer of a fructose moiety from sucrose to a water molecule (hydrolysis) or to an acceptor molecule (transferase), yielding inulin. Bacterial inulin production is rare and a biochemical analysis of inulosucrase enzymes has not been reported. Here we report biochemical characteristics of a purified recombinant inulosucrase enzyme from Lactobacillus reuteri. It displayed Michaelis–Menten type of kinetics with substrate inhibition for the hydrolysis reaction. Kinetics of the transferase reaction is best described by the Hill equation, not reported before for these enzymes. A C-terminal deletion of 100 amino acids did not appear to affect enzyme activity or product formation. This truncated form of the enzyme was used for biochemical characterization.