Identification and molecular characterization of a psychrophilic GH1 ?-glucosidase from the subtropical soil microorganism Exiguobacterium sp. GXG2.

ABSTRACT: The products of bacterial ?-glucosidases with favorable cold-adapted properties have industrial applications. A psychrophilic ?-glucosidase gene named bglG from subtropical soil microorganism Exiguobacterium sp. GXG2 was isolated and characterized by function-based screening strategy. Results of multiple alignments showed that the derived protein BglG shared 45.7% identities with reviewed ?-glucosidases in the UniProtKB/Swiss-Prot database. Functional characterization of the ?-glucosidase BglG indicated that BglG was a 468 aa protein with a molecular weight of 53.2 kDa. The BglG showed the highest activity in pH 7.0 at 35 °C and exhibited consistently high levels of activity within low temperatures ranging from 5 to 35 °C. The BglG appeared to be a psychrophilic enzyme. The values of Km, Vmax, kcat, and kcat/Km of recombinant BglG toward ?NPG were 1.1 mM, 1.4 µg/mL/min, 12.7 s-1, and 11.5 mM/s, respectively. The specific enzyme activity of BglG was 12.14 U/mg. The metal ion of Ca2+ and Fe3+ could stimulate the activity of BglG, whereas Mn2+ inhibited the activity. The cold-adapted ?-glucosidase BglG displayed remarkable biochemical properties, making it a potential candidate for future industrial applications.

SUBMITTER: Yin B 

PROVIDER: S-EPMC6773797 | biostudies-literature | 2019 Oct

REPOSITORIES: biostudies-literature