Structural and functional insights into β-glucosidase derived from Thermoproteus sp. AZ2

Area of Science:

• Biochemistry
• Enzymology
• Structural Biology

Background:

• β-glucosidase (BGL) is crucial for lignocellulosic biomass conversion.
• Understanding BGL structure and function is key for industrial applications.
• Thermoproteus sp. AZ2-derived BGL (TsBGL2) is a potential candidate for high-temperature processes.

Purpose of the Study:

• To investigate the enzymatic activity and structural characteristics of TsBGL2.
• To determine the optimal conditions for TsBGL2 activity.
• To elucidate the thermostabilization mechanisms of TsBGL2 through structural analysis.

Main Methods:

• Enzymatic assays to determine optimal temperature and pH.
• Thermal stability assays.
• High-resolution crystal structure determination of TsBGL2.
• Site-directed mutagenesis to create Δ(473-495) TsBGL2 mutant.

Main Results:

• TsBGL2 demonstrated optimal activity at 95°C and pH 5.0.
• TsBGL2 exhibited exceptional thermal stability, retaining over 95% activity after 10 hours at 99°C.
• Crystal structures revealed a canonical (α/β)8-barrel catalytic domain and identified thermostabilization features.
• Deletion of residues 473-495 significantly reduced TsBGL2's thermal stability.

Conclusions:

• TsBGL2 is a highly thermostable β-glucosidase with potential industrial applications.
• Structural insights provide a basis for understanding its thermostability.
• Further research on TsBGL2 can facilitate enzyme engineering for enhanced performance.