Characterizing the Hot Spots Involved in RON-MSP beta Complex Formation Using In Silico Alanine Scanning Mutagenesis and Molecular Dynamics Simulation

Abstract

Purpose: Implication of protein-protein interactions (PPIs) in development of many diseases such as cancer makes them attractive for therapeutic intervention and rational drug design. RON (Recepteur d'Origine Nantais) tyrosine kinase receptor has gained considerable attention as promising target in cancer therapy. The activation of RON via its ligand, macrophage stimulation protein (MSP) is the most common mechanism of activation for this receptor. The aim of the current study was to perform in silico alanine scanning mutagenesis and to calculate binding energy for prediction of hot spots in proteinprotein interface between RON and MSP beta chain (MSP beta). Methods: In this work the residues at the interface of RON-MSP beta complex were mutated to alanine and then molecular dynamics simulation was used to calculate binding free energy. Results: The results revealed that Gln(193), Arg(220), Glu(287), Pro(288), Glu(289), and His(424) residues from RON and Arg(521), His(528), Ser(565), Glu(658), and Arg(683) from MSP beta may play important roles in protein-protein interaction between RON and MSP. Conclusion: Identification of these RON hot spots is important in designing anti-RON drugs when the aim is to disrupt RON-MSP interaction. In the same way, the acquired information regarding the critical amino acids of MSP beta can be used in the process of rational drug design for developing MSP antagonizing agents, the development of novel MSP mimicking peptides where inhibition of RON activation is required, and the design of experimental site directed mutagenesis studies.