Hydrolysis of Nonpolar n-Alkyl Ferulates by Feruloyl Esterases.
Ferulic acid is one of the major phenolic acids in plants and can be found esterified to plant cell wall components, but also as long-chain n-alkyl and steryl esters. Microbial feruloyl esterases may play a role in the bioavailability of phenolic acids during human and animal digestion. It is therefore of interest if feruloyl esterases are capable of hydrolyzing nonpolar ferulic acid esters. A series of n-alkyl ferulates with increasing lipophilicity were enzymatically synthesized, and the kinetic constants of their hydrolysis by four feruloyl esterases and a lipase as control were determined. A decrease in Kmand kcatcould be observed with decreased substrate polarity for all of the feruloyl esterases. Only one feruloyl esterase and the control lipase showed hydrolytic activity toward octadecyl ferulate. These results led to the conclusion that lipophilic ferulates are poor substrates for known feruloyl esterases and more specific esterases/lipases need to be identified.
Institute of Food, Nutrition and Health, ETH Zurich , Schmelzbergstrasse 9, CH-8092 Zurich, Switzerland.
Aline
A
Schär
Institute of Food, Nutrition and Health, ETH Zurich , Schmelzbergstrasse 9, CH-8092 Zurich, Switzerland.
Isabel
I
Sprecher
Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens , 5 Iroon Polytechniou Str., Zografou Campus, 15700 Athens, Greece.
Evangelos
E
Topakas
Aix Marseille Université , INRA BBF UMR_A 1163 Biodiversité et Biotechnologie Fongiques, 13288 Marseille cedex 02, France.|INRA BBF UMR_A1163, Polytech Marseille , 163 Avenue de Luminy, 13288 Marseille cedex 02, France.
Craig B
CB
Faulds
Institute of Food, Nutrition and Health, ETH Zurich , Schmelzbergstrasse 9, CH-8092 Zurich, Switzerland.
Laura
L
Nyström
D001234:Aspergillus niger / Q000737:chemistry / Q000201:enzymology*; D002265:Carboxylic Ester Hydrolases / Q000737:chemistry* / Q000378:metabolism; D003373:Coumaric Acids / Q000737:chemistry / Q000378:metabolism*; D005656:Fungal Proteins / Q000737:chemistry* / Q000378:metabolism; D006868:Hydrolysis; D007700:Kinetics
D003373:Coumaric Acids; D005656:Fungal Proteins; C004999:ferulic acid; D002265:Carboxylic Ester Hydrolases; C070196:feruloyl esterase
A. niger feruloyl esterase; C. thermocellum feruloyl esterase; R. miehei lipase; alkyl ferulates; ferulic acid; feruloyl esterase