In silico approaches towards understanding CALB using molecular dynamics simulation and docking

Candida antarctica lipase B (CALB), a serine protease, is involved in the hydrolysis of substrates at the aqueous lipid interface. There is a significant role played by the helices in serine proteases including acting as a flap covering the active site region. The α5 and α10 helices in the path to the active site of CALB appear to play an important role in the region. This study investigates these helices by mutational studies, docking and molecular dynamics simulations. The mutations were selected based on their proximity to the active site and their presence at the α10-helix in the path of the active site. Molecular dynamics studies reveal the flexibility, stability and hydrogen bonding ability of the α5 helix. The radius of gyration (R _g) clearly showed the compactness of the structure. Docking studies show the changes occurring at the protein's binding site before and after 15 ns of simulation. Results from the study demonstrate the importance of the two helices α5 and α10 in the stability of CALB.