title: Kinetic properties of an inulosucrase from Lactobacillus reuteri 121.
abstract: 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.
authors.affiliation: Centre for Carbohydrate Bioengineering, TNO-RUG, University of Groningen, PO Box 14, 9750 AA Haren, The Netherlands.
authors.forename: S A F T
authors.initials: SA
authors.lastname: van Hijum
authors.forename: M J E C
authors.initials: MJ
authors.lastname: van der Maarel
authors.forename: L
authors.initials: L
authors.lastname: Dijkhuizen
mesh_terms: D006602:Hexosyltransferases / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D007778:Lactobacillus / Q000201:enzymology*; D008670:Metals / Q000378:metabolism / Q000494:pharmacology; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D017384:Sequence Deletion; D013696:Temperature; D001426:Bacterial Proteins
chemical_list: D006602:Hexosyltransferases; D008670:Metals; D011994:Recombinant Proteins; C021451:inulosucrase; D001426:Bacterial Proteins