This study investigated the chitosanase from Aspergillus fumigatus, which shows potential for production but lacks ideal thermal stability. Using Alphafold2, the researchers predicted the structure, showing high similarity to the experimental structure of chitosanase V-CSN. Molecular dynamics simulations at 300K and 350K revealed high flexibility in the binding site. Heating increased RMSD and RMSF of the binding site, with loop6 closure hindering binding. Decreased hydrogen bond proportions at the binding site indicated disruption as a main interaction factor for conformational changes. Energetically contributing residues were also in the highly flexible region, explaining decreased activity stability at high temperatures. These findings offer directions for modifying thermal stability and provide insights into studying proteins without experimental structures.

Qian Wang, Song Liu, Kecheng Li, Ronge Xing, Xiaolin Chen, Pengcheng Li