Expression, characterization and structural modelling of a feruloyl esterase from the thermophilic fungus Myceliophthora thermophila.
A ferulic acid esterase (FAE) from the thermophilic fungus Myceliophthora thermophila (synonym Sporotrichum thermophile), belonging to the carbohydrate esterase family 1 (CE-1), was functionally expressed in methylotrophic yeast Pichia pastoris. The putative FAE from the genomic DNA was successfully cloned in P. pastoris X-33 to confirm that the enzyme exhibits FAE activity. The recombinant FAE was purified to its homogeneity (39 kDa) and subsequently characterized using a series of model substrates including methyl esters of hydroxycinnamates, alkyl ferulates and monoferuloylated 4-nitrophenyl glycosides. The substrate specificity profiling reveals that the enzyme shows a preference for the hydrolysis of methyl caffeate and p-coumarate and a strong preference for the hydrolysis of n-butyl and iso-butyl ferulate. The enzyme was active on substrates containing ferulic acid ester linked to the C-5 and C-2 linkages of arabinofuranose, whilst it was found capable of de-esterifying acetylated glucuronoxylans. Ferulic acid (FA) was efficiently released from destarched wheat bran when the esterase was incubated together with an M3 xylanase from Trichoderma longibrachiatum (a maximum of 41% total FA released after 1 h incubation). Prediction of the secondary structure of MtFae1a was performed in the PSIPRED server whilst modelling the 3D structure was accomplished by the use of the HH 3D structure prediction server.
School of Chemical Engineering, National Technical University of Athens, Athens, Greece.
Evangelos
E
Topakas
Maria
M
Moukouli
Maria
M
Dimarogona
Paul
P
Christakopoulos
D000595:Amino Acid Sequence; D002265:Carboxylic Ester Hydrolases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D015870:Gene Expression; D008958:Models, Molecular; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010843:Pichia / Q000235:genetics; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D020037:Sordariales / Q000201:enzymology* / Q000235:genetics; D013379:Substrate Specificity
D011994:Recombinant Proteins; D002265:Carboxylic Ester Hydrolases; C070196:feruloyl esterase