title: An esterase from the basidiomycete Pleurotus sapidus hydrolyzes feruloylated saccharides.
abstract: Investigating the secretion of esterases by the basidiomycetous fungus Pleurotus sapidus in a Tween 80-rich nutrient medium, an enzyme was discovered that hydrolyzed the ester bond of feruloylated saccharides. The enzyme was purified by ion exchange and size exclusion chromatography. Polyacrylamide gel electrophoresis analysis showed a monomeric protein of about 55 kDa. The complete coding sequence with an open reading frame of 1,665 bp encoded a protein (Est1) consisting of 554 amino acids. The enzyme showed no significant homology to any published feruloyl esterase sequences, but possessed putative conserved domains of the lipase/esterase superfamily. Substrate specificity studies classified the new enzyme as type-A feruloyl esterase, hydrolyzing methyl ferulate, methyl sinapate, and methyl p-coumarate but no methyl caffeate. The enzyme had a pH optimum of 6 and a temperature optimum at 50 °C. Ferulic acid was efficiently released from ferulated saccharides, and the feruloyl esterase exhibited moderate stability in biphasic systems (50 % toluene or tert-butylmethyl ether).
authors.affiliation: Institut für Lebensmittelchemie der Gottfried Wilhelm Leibniz Universität Hannover, Callinstraße 5, 30167 Hannover, Germany. Diana.Linke@lci.uni-hannover.de
authors.forename: Diana
authors.initials: D
authors.lastname: Linke
authors.forename: Rene
authors.initials: R
authors.lastname: Matthes
authors.forename: Manfred
authors.initials: M
authors.lastname: Nimtz
authors.forename: Holger
authors.initials: H
authors.lastname: Zorn
authors.forename: Mirko
authors.initials: M
authors.lastname: Bunzel
authors.forename: Ralf G
authors.initials: RG
authors.lastname: Berger
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D002265:Carboxylic Ester Hydrolases / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D016000:Cluster Analysis; D003373:Coumaric Acids / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D004795:Enzyme Stability; D005960:Glucosides / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008969:Molecular Sequence Data; D008970:Molecular Weight; D016366:Open Reading Frames; D010802:Phylogeny; D020076:Pleurotus / Q000201:enzymology*; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D003373:Coumaric Acids; D005960:Glucosides; C004999:ferulic acid; D002265:Carboxylic Ester Hydrolases; C070196:feruloyl esterase