title: Dose-dependent significance of monosaccharides on intracellular alpha-L-rhamnosidase activity from Pseudoalteromonas sp.
abstract: Intracellular alpha-L-rhamnosidase (EC 3.2.1.40) from the psychrotolerant Pseudoalteromonas sp. 005NJ showed a dose-dependent inhibition for L-rhamnose (IC(50) = 20 mM) and D-ribose (IC(50) = 95 mM), whereas D-glucose and L-fucose presented a lower inhibition, with IC(50) values as high as >0.5 and >0.2 M, respectively. On the other hand, D-fructose enhanced enzyme activity threefold, reaching a plateau of maximum specific activity between 0.2 and 0.4 M of this monosaccharide. Both effects, low inhibition and stimulation, caused by key fruit sugars (glucose and fructose), make this biocatalyst an interesting system in terms of its potential application for debittering fruit juices.
authors.affiliation: Depto. de Química-CONICET, FCEyN, Universidad Nacional de La Pampa (UNLPam), Av. Uruguay 151, Santa Rosa, La Pampa 6300, Argentina. javierbreccia@exactas.unlpam.edu.ar
authors.forename: Laura S
authors.initials: LS
authors.lastname: Mazzaferro
authors.forename: Gaston A
authors.initials: GA
authors.lastname: Orrillo
authors.forename: Pablo
authors.initials: P
authors.lastname: Ledesma
authors.forename: Javier D
authors.initials: JD
authors.lastname: Breccia
mesh_terms: D003080:Cold Temperature; D004791:Enzyme Inhibitors / Q000378:metabolism; D019649:Food Industry; D005632:Fructose / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism*; D006026:Glycoside Hydrolases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D020128:Inhibitory Concentration 50; D031161:Pseudoalteromonas / Q000201:enzymology* / Q000378:metabolism; D012210:Rhamnose / Q000378:metabolism; D012266:Ribose / Q000378:metabolism
chemical_list: D004791:Enzyme Inhibitors; D005632:Fructose; D012266:Ribose; D006026:Glycoside Hydrolases; C022525:alpha-L-rhamnosidase; D005947:Glucose; D012210:Rhamnose