Exploration of the binding modes of L-asparaginase complexed with its amino acid substrates by molecular docking, dynamics and simulation.

Acute lymphocytic leukemia (ALL) is an outrageous disease worldwide. L-Asparagine (L-Asn) and L-glutamine (L-Gln) deamination plays crucial role in ALL treatment. Role of Erwinaze(®) (L-asparaginase from Erwinia chrysanthemi) in regulation of L-Asn and L-Gln has been confirmed by the experimental studies. Therapeutic research against ALL remained elusive with the lack of structural information on Erwinaze(®) enzyme. In this present study, homology model of the Erwinaze(®) was developed using MODELLER and the same was validated by various quality indexing tools. For the apo state enzyme and ligand bound state complexes molecular dynamics (MD) simulation was performed. The trajectory analysis showed the confirmational changes of structures in the dynamic system. Ligand binding mechanisms were studied using different docking tools to interpret the various ligand-receptor interactions and binding free energies. MD simulation of docked complex with L-Gln ligand substrate showed the defined structural folding with stable conformation over the L-Asn complex in dynamic environment. This research reports give much more information on structural and functional aspects of Erwinaze(®) with its ligands which may be useful in designing of effective therapeutics for ALL.