Table 2 Substrate spectrum of EngU. Hydrolytic activities of EngU were determined at 80 °C in McIlvaine buffer at pH 5.5.

From: A metagenome-derived thermostable β-glucanase with an unusual module architecture which defines the new glycoside hydrolase family GH148

Substrate

Moiety

glycosidic linkage

Relative activity (%)

β-Glucan (barley)

β-D-glucopyranose

β-1,3; β-1,4 linear

100

Lichenin (C. islandica)

β-D-glucopyranose

β-1,3; β-1,4 linear

93

Carboxymethyl-cellulose

β-D-glucopyranose with carboxylmethylated hydroxyl groups

β-1,4 linear

23

Hydroxyethylcellulose

β-D-glucopyranose

β-1,4 linear

2

Xyloglucan

β-D-glucopyranose, α-D-xylopyranose side chains

β-1,4 linear

<1

Substrates showing no activity (below the detection limit of the DNS or the bromo-chloro-indoxyl assay) with EngU after overnight incubation

Pachyman (P. cocos)

β-D-glucopyranose

β-1,3

 

Zymosan (C. cerevisae)

β-D-glucopyranose

β-1,3 linear, protein complex

 

Curdlan (A. faecalis)

β-D-glucopyranose

β-1,3 linear

 

Auxoferm (S. cerevisae)

β-D-glucopyranose

β-1,3

 

Laminarin (L. digitata)

β-D-glucopyranose

β-1,3; 1,6 linear

 

Microcrystalline cellulose

β-D-glucopyranose

β-1,4 crystaline structure

 

Arabinoxylan

arabinose: 36%, xylose: 51%, glucose: 6.5%, mannose: 4.4%, galactose: 1.6%

β-1,4; β-1,3 branched

 

Dextran

α-D-glucopyranose

α-1,6; α-1,4; α-1,3;

 

Galactan

galactose: 87%, arabinose: 5%, rhamnose: 1%, xylose: 1%, galacturonic acid: 5%, other sugars

β-1,4; β-1,3 branched

 

Galactomannan

β-D-mannopyranose, β-D-galactopyranose side chains (62:38)

β-D-1,4 and side chain α-D-1,6 branched

 

Inulin (dahlia bulb)

fructose, glucose

β-2,1 linear

 

Laminarin

β-D-glucopyranose

β-D-1,3 with β-D-1,6 branches

 

Levan (E. herbicola)

α-D-fructose

α-D-2,6 linear

 

Mannan

mannose: 98%, galactose: ca. 1%

β-D-1,4 linear

 

Mannan (Ivory nut)

mannose: 99%, arabinose, xylose: traces

β-D-1,4 linear

 

“Pectic galactan” (Lupine)

galactose: 74%, arabinose: 17%, rhamnose: 3%, xylose: 1%, galacturonic acid: 5%, glucose (trace)

β-D-1,4 linear

 

“Pectic galactan” (potato)

galactose: 82%, arabinose: 6%, rhamnose: 3%, galacturonic acid: 9%

β-D-1,4 linear

 

Polygalacturonic acid

α-D-galacturonic acid

α-D-1,4 linear

 

Polyoses (Hemicellulose)

xylose, arabinose, glucose, mannose, galactose

  

Pullulan

maltotriose

Glu: α-D-1,4/ Maltotriose: α-D-1,6 linear

 

Rhamnogalacturonan I

α-D-Galacturonic acid, α-L-rhamnopyranose

GalUA: α-D-1,6/ Rha: α-L-1,2 branched

 

Sinistrin

β-D-Fructopyranose

β-D-1,2 and 1,6 branched

 

X-Gal

5-Bromo-4-chloro-3-indoxyl-β-D-galactopyranoside

  

Xylan (Birch wood)

β-D-Xylopyranose

β-D-1,4 branched

 

Xylan (Oat spelt)

β-D-Xylopyranose

β-D-1,4 branched

 

Xylan (Larch wood)

β-D-Xylopyranose

β-D-1,4 branched

 
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