Exo-inulinase of Aspergillus niger N402: A hydrolytic enzyme with significant transfructosylating activity

article


Goosen, C.

Maarel, M.J. E.C. van der

Dijkhuizen, L.
The purified exo-inulinase enzyme of Aspergillus niger N402 (AngInuE; heterologously expressed in Escherichia coli) displayed a sucrose:inulin (S/I) hydrolysis ratio of 2.3, characteristic for a typical exo-inulinase. The enzyme also had significant transfructosylating activity with increasing sucrose concentrations, producing various oligosaccharides. The AngInuE protein molecular mass was 57 kDa, close to the calculated value for the mature protein. AngInuE thus was active as a monomeric, non-glycosylated protein. Contradictory data on hydrolysis/transfructosylation activity ratios have been published for the (almost) identical (but monomeric or dimeric and glycosylated) exo-inulinases of other aspergilli. Our data clearly show that the AngInuE enzyme, produced in and purified from E. coli, is a broad specificity exo-inulinase that also has significant transfructosylating activity with sucrose. Analysis of site-directed mutants of AngInuE showed that the glycoside hydrolase family 32 conserved domain G is important for catalytic efficiency, with a clear role in hydrolysis of both sucrose and fructans.
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Aspergillus nigerExo-inulinaseGlycoside hydrolaseHydrolysisSVEVF motifTransfructosylationEnzymesEscherichia coliHydrolysisPolysaccharidesPurificationSugar (sucrose)SugarsWater pollutionAspergillus nigerExo-inulinaseGlycoside hydrolaseSVEVF motifTransfructosylationEnzyme activityfructanfungal enzymeglycosidasehydrolaseinulinaseoligosaccharideprotein AngInuEsucrosearticleAspergillus nigercarbohydrate synthesiscatalysisconcentration responseenzyme activityenzyme analysisenzyme purificationenzyme specificityenzyme substrateenzyme synthesisEscherichia colifungal strainhydrolysismolecular weightnonhumannucleotide sequenceprotein analysisprotein domainsite directed mutagenesisAspergillus nigerEscherichia coli
TNO Identifier
241000
Repository link
https://resolver.tno.nl/uuid:2a150c73-272e-4085-8528-c4f12450e3d3
ISSN
10242422
Source
Biocatalysis and Biotransformation, 26(1-2), pp. 49-58.
Pages
49-58
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