the covariance matrix, a set of eigenvectors and eigenvalues were generated. For each eigenvector, one corresponding eigenvalue produced explains the energetic contribution of each MEDChem Express 852391-19-6 component to the motion. The protein molecular segments that are responsible for the most significant collective motions can be acknowledged through PCA. Backbone C-alpha bonds trajectories were obtained and analyzed by using gcovar and ganaeig of GROMACS inbuilt tool. Flavopiridol has been suggested to inhibit the in vitro kinase activity of the CDK4 protein . Amino acid variation may affect the inhibitory action of flavopiridol on the CDK4 protein. Numbers of studies have been performed to find an ATP-competitive inhibitor that binds specifically to the CDK4 protein . Additionally, further studies have attempted to optimise inhibitor binding and specificity for CDK4 using structure-based design methods . In this study, we examined the binding affinity of flavopiridol with native and mutant CDK4 proteins using AutodockVina, a computational docking program. Before performing the docking analysis, ATP binding sites of the native CDK4 protein were identified. The amino acid residues present in the ATP binding clefts of CDK4 are ILE12, VAL20, ALA33, VAL77, PHE93, GLU94, HIS95, VAL96, GLN98, ASP99, THR102, GLU144, LEU147, ALA157 and ASP158. Computational docking Oltipraz analysis also indicated the inhibitory action of flavopiridol with CDK4, as observed in in vitro studies.e., the inhibitor flavopiridol binds exactly at the ATP binding site of the native CDK4 protein . However, flavopiridol binds residues outside of the ATP-binding cleft in mutant CDK4 structures . A change in the binding residues will indeed affect the complementarities between the mutant proteins and flavopiridol. Noncovalent interactions and shape complementarity are important factors for the maintenance of protein-ligand affinity. Non-covalent bonds, such as van der Waals contacts, electrostatic forces and hydrogen bonds, are the primary forces involved in protein-ligand interactions. Calculating the interaction energies of non-covalent bonds is vital to understanding the binding ability of the ligand molecule. The number o
