Cloning, expression and characterization of a glycoside hydrolase family 51 α-l-arabinofuranosidase from DSM 571.

The present study focused on the characterization of a glycoside hydrolase 51 family α-l-arabinofuranosidase named TtAbf51 from thermophile DSM 571. The recombinant TtAbf51 with 497 amino acids was successfully expressed in BL21(DE3) and purified via nickel affinity chromatography, and native protein was a dimer verified by size exclusion chromatography. The TtAbf51 showed an optimum pH and temperature of 5.5 and 55 °C, and was relatively stable at pH 5.0-8.0 and up to 60 °C for 2 h of incubation. In addition, TtAbf51 was significantly inhibited by Cu, Zn and 1 mM or 10 mM SDS. In the presence of 800 mM arabinose, the residual activity remained over 40% of the initial activity. In addition, the recombinant enzyme possessed a good catalytic effect for both synthesized and natural substrates, and the specific enzyme activity toward CM-linear arabinan reached 426.5 μmol min mg. In summary, this study provides an α-l-arabinofuranosidase with potential in the synergistic hydrolysis of hemicellulose to fermentable sugars in applications such as liquid biofuels, food and beverages, and related industries.