Computational Investigation on the MDM2-Idasanutlin Interaction using the Potential of Mean Force method

2021 ◽  
Vol 15 ◽  
Author(s):  
Pundarikaksha Das ◽  
Venkata Satish Kumar Mattaparthi

Background: The Murine Double Minute 2 (MDM2) protein is a well-studied primary negative regulator of the tumor suppressor p53 molecule. Therefore, nowadays, many research studies have focused on the inhibition of MDM2 with potent inhibitors. Idasanutlin (RG7388) is a well-studied small molecule, the antagonist of MDM2 with potential antineoplastic activity. Nevertheless, the highly significant information about the free energy profile, intermediates, and the association of receptor and ligand components in the MDM2-idasanutlin complex remains unclear. Objective: To study the free energy profile of the MDM2-idasanutlin complex in terms of the Potential of Mean Force (PMF) method. Method: We have used the PMF method coupled with umbrella sampling simulations to generate the free energy profile for the association of N-Terminal Domain (NTD) of MDM2 and idasanutlin and a specific reaction coordinate for identifying transition states, intermediates as well as the relative stabilities of the endpoints. We have also determined the binding characteristics and interacting residues at the interface of the MDM2-idasanutlin complex from the Binding Free Energy (BFE) and Per Residue Energy Decomposition (PRED) analyses. Results: The PMF minima for the MDM2-idasanutlin complex was observed at a center of mass (CoM) distance of separation of 11 Å with dissociation energy of 17.5 kcal mol-1. As a function of the distance of separation of MDM2 from idasanutlin. We also studied the conformational dynamics and stability of the NTD of MDM2. We found a high binding affinity between MDM2 and idasanutlin (∆Grinding = -3.19 kcal mol-1). We found that in MDM2, the residues MET54, VAL67, and LEU58 provide the highest energy input for the interaction between MDM2 and idasanutlin. Conclusion: Our results in this study illustrate the significant structural and binding features of the MDM2-idasanutlin complex that may be useful in developing potent inhibitors of MDM2.

2021 ◽  
Author(s):  
Curtis Goolsby ◽  
Ashkan Fakharzadeh ◽  
Mahmoud Moradi

AbstractWe have formulated a Riemannian framework for describing the geometry of collective variable spaces of biomolecules within the context of molecular dynamics (MD) simulations. The formalism provides a theoretical framework to develop enhanced sampling techniques, path-finding algorithms, and transition rate estimators consistent with a Riemannian treatment of the collective variable space, where the quantities of interest such as the potential of mean force (PMF) and minimum free energy path (MFEP) remain invariant under coordinate transformation. Specific algorithms within this framework are discussed such as the Riemannian umbrella sampling, the Riemannian string method, and a Riemannian-Bayesian estimator of free energy and diffusion constant, which can be used to estimate the transition rate along an MFEP.


2014 ◽  
Vol 11 (97) ◽  
pp. 20140399 ◽  
Author(s):  
L. Bongini ◽  
V. Lombardi ◽  
P. Bianco

The overstretching transition in torsionally unconstrained DNA is studied by means of atomistic molecular dynamics simulations. The free-energy profile as a function of the length of the molecule is determined through the umbrella sampling technique providing both a thermodynamic and a structural characterization of the transition pathway. The zero-force free-energy profile is monotonic but, in accordance with recent experimental evidence, becomes two-state at high forces. A number of experimental results are satisfactorily predicted: (i) the entropic and enthalpic contributions to the free-energy difference between the basic (B) state and the extended (S) state; (ii) the longitudinal extension of the transition state and (iii) the enthalpic contribution to the transition barrier. A structural explanation of the experimental finding that overstretching is a cooperative reaction characterized by elementary units of approximately 22 base pairs is found in the average distance between adenine/thymine-rich regions along the molecule. The overstretched DNA adopts a highly dynamical and structurally disordered double-stranded conformation which is characterized by residual base pairing, formation of non-native intra-strand hydrogen bonds and effective hydrophobic screening of apolar regions.


Author(s):  
Norifumi Yamamoto

The contributing factors that cause the aggregation-induced emission (AIE) are determined by identifying characteristic differences in the free energy profiles of the AIE processes of the AIE-active E-form of CN-MBE and the inactive Z-form.


2016 ◽  
Vol 144 (4) ◽  
pp. 044703 ◽  
Author(s):  
Carlos Braga ◽  
Jordan Muscatello ◽  
Gabriel Lau ◽  
Erich A. Müller ◽  
George Jackson

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