A thermostable and highly active fungal GH3 β-glucosidase generated by random and saturation mutagenesis.

ABSTRACT: Enhancing the thermostability of cellulose-degrading enzymes is pivotal for establishing an efficient bioconversion system from cellulosic materials to value-added compounds. Here, by introducing random and saturation mutagenesis into the Thermoascus aurantiacus β-glucosidase gene, we generated a hyperthermostable mutant with five amino acid substitutions. Analysis of temperature-induced unfolding revealed the involvement of each replacement in the increased T_m value. Structural analysis showed that all replacements are located at the periphery of the catalytic pocket. D433N replacement, which had a pronounced thermostabilizing effect (ΔT_m ＝ 4.5°C), introduced an additional hydrogen bond with a backbone carbonyl oxygen in a long loop structure. The mutant enzyme expre

SUBMITTER: Matsuzaki C 

PROVIDER: S-EPMC12321500 | biostudies-literature | 2025 Mar

REPOSITORIES: biostudies-literature