A New GH43 α-Arabinofuranosidase from Humicola insolens Y1: Biochemical Characterization and Synergistic Action with a Xylanase on Xylan Degradation

Abstract

A new α-arabinofuranosidase gene (Hiabf43) was cloned from Humicola insolens Y1 and successfully expressed in Pichia pastoris GS115. Deduced HiAbf43 contained a putative signal peptide and a catalytic domain of glycoside hydrolase (GH) family 43. Purified recombinant HiAbf43 showed optimal activity at pH 5.0 and 50 °C, and was active over a broad pH range. The enzyme was specific for the cleavage of α-1,3-linkage and showed high activity against 4-nitrophenyl α-L-arabinofuranoside, debranched arabinan, and sugar beet arabinan. Sequential addition of HiAbf43 followed by Xyn11A increased the degradation efficiency of birchwood and beechwood xylans but not wheat arabinoxylan. The synergy degree was high up to 1.21-fold.

Development of a thermophilic coculture for corn fiber conversion to ethanol

“…Activity of the purified enzymes was determined using p-nitrophenyl glycosides (Supplementary Table 7). The specific activity of β-Xylp_1710 is one of the highest reported for β-xylosidases [31][32][33][34][35] while the measured activities on pNP α-L-arabinofuranoside were up to 100-fold lower than others 31,36 . There have been very few α-xylosidases described 37 .…”

Novel Trifunctional Xylanolytic Enzyme Axy43A from Paenibacillus curdlanolyticus Strain B-6 Exhibiting Endo-Xylanase, β- d -Xylosidase, and Arabinoxylan Arabinofuranohydrolase Activities

“…According to the CAZy database, multifunctional xylanolytic enzymes are represented in GH43, including bifunctional ␤-xylosidase/␣-L-arabinofuranosidase from Clostridium stercorarium (13), Paenibacillus woosongensis (14), Humicola insolens (15), Thermoanaerobacter ethanolicus (16), Phanerochaete chrysosporium (17), and Thermotoga thermarum (18); trifunctional endo-xylanase/␤-xylosidase and ␣-Larabinofuranosidase from Paenibacillus curdlanolyticus B-6 (19); and multifunctional ␤-xylosidase/␣-L-arabinofuranosidase/␤-1,4 lactase/␣-1,6 raffinase/␣-1,6 stachyase/␤-galactosidase/␣-1,4 glucosidase from a cow rumen microbial consortium (7). GH43 is subdivided into subfamilies (1 to 37) due to the sequence diversity of its enzymes (20).…”

Three‐dimensional structures and functional studies of two GH43 arabinofuranosidases from Weissella sp. strain 142 and Lactobacillus brevis

“…Selectivity for branched arabinan has thus far only been reported for two fungal enzymes (Abn4 from Ch. lucknowense C1 K [17], and Hiabf43 from H. insolens Y1 [18]) which were highly active on branched, but not very active on linear arabinan. Unfortunately, no structural data are yet available for enzymes with this type of activity in the subfamily.…”

“…Fewer enzymes are characterized in subfamily 26 (which, however, includes more than 800 genes), and the characterized candidates include three published bacterial enzymes from Streptomyces avermitilis , Streptomyces chartreusis , and L. brevis DSM20054 and three fungal enzymes from Chaetomium sp. , Chrysosporium lucknowense , and Humicola insolens Y1 . All characterized candidates are reported as exo‐acting Arafs, although the linkage specificity appears to vary between the bacterial and fungal enzymes.…”