Authors: Diana Linke Rene Matthes Manfred Nimtz Holger Zorn Mirko Bunzel Ralf G Berger
Publish Date: 2012/12/01
Volume: 97, Issue: 16, Pages: 7241-7251
Abstract
Investigating the secretion of esterases by the basidiomycetous fungus Pleurotus sapidus in a Tween 80rich 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 1665 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 typeA feruloyl esterase hydrolyzing methyl ferulate methyl sinapate and methyl pcoumarate 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 tertbutylmethyl etherWe are grateful to E Allerdings A Heinze and C Tyl for experimental support NMR instrumentation was provided with funds from the National Science Foundation NSF BIR961477 the University of Minnesota Medical School and the Minnesota Medical Foundation
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