scholarly journals In SilicoScreening and Molecular Dynamics Simulation of Disease-Associated nsSNP in TYRP1 Gene and Its Structural Consequences in OCA3

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Balu Kamaraj ◽  
Rituraj Purohit

Oculocutaneous albinism type III (OCA3), caused by mutations of TYRP1 gene, is an autosomal recessive disorder characterized by reduced biosynthesis of melanin pigment in the hair, skin, and eyes. The TYRP1 gene encodes a protein called tyrosinase-related protein-1 (Tyrp1). Tyrp1 is involved in maintaining the stability of tyrosinase protein and modulating its catalytic activity in eumelanin synthesis. Tyrp1 is also involved in maintenance of melanosome structure and affects melanocyte proliferation and cell death. In this work we implemented computational analysis to filter the most probable mutation that might be associated with OCA3. We found R326H and R356Q as most deleterious and disease associated by using PolyPhen 2.0, SIFT, PANTHER, I-mutant 3.0, PhD-SNP, SNP&GO, Pmut, and Mutpred tools. To understand the atomic arrangement in 3D space, the native and mutant (R326H and R356Q) structures were modelled. Finally the structural analyses of native and mutant Tyrp1 proteins were investigated using molecular dynamics simulation (MDS) approach. MDS results showed more flexibility in native Tyrp1 structure. Due to mutation in Tyrp1 protein, it became more rigid and might disturb the structural conformation and catalytic function of the structure and might also play a significant role in inducing OCA3. The results obtained from this study would facilitate wet-lab researches to develop a potent drug therapies against OCA3.

2019 ◽  
Vol 19 (2) ◽  
pp. 461
Author(s):  
Herlina Rasyid ◽  
Bambang Purwono ◽  
Thomas S Hofer ◽  
Harno Dwi Pranowo

Lung cancer was a second common cancer case due to the high cigarette smoking activity both in men and women. One of protein receptor which plays an important role in the growth of the tumor is Epidermal Growth Factor Receptor (EGFR). EGFR protein is the most frequent protein mutation in cancer and promising target to inhibit the cancer growth. In this work, the stability of the hydrogen bond as the main interaction in the inhibition mechanism of cancer will be evaluated using molecular dynamics simulation. There were two compounds (A1 and A2) as new potential inhibitors that were complexed against the EGFR protein. The dynamic properties of each complexed were compared with respect to erlotinib against EGFR. The result revealed that both compounds had an interaction in the main catalytic area of protein receptor which is at methionine residue. Inhibitor A1 showed additional interactions during simulation time but the interactions tend to be weak. Inhibitor A2 displayed a more stable interaction. Following dynamics simulation, binding free energy calculation was performed by two scoring techniques MM/GB(PB)SA method and gave a good correlation with the stability of the complex. Furthermore, potential inhibitor A2 had a lower binding free energy as a direct consequence of the stability of hydrogen bond interaction.


2019 ◽  
Vol 22 (8) ◽  
pp. 546-554
Author(s):  
Mohadeseh Bazoobandi ◽  
Mohammad R. Bozorgmehr ◽  
Ali Mahmoudi ◽  
Ali Morsali

Aim and Objective: The stability of the G-quadruplex structure can increase its activity in telomerase inhibiting cancer cells. In this study, a molecular dynamics simulation method was used to study the effect of three phenanthroline-based ligands on the structure of G-quadruplex at the temperatures of 20, 40, 60 and 80°C. Materials and Methods: RMSD values and frequency of calculated RMSD in the presence and absence of ligands show that ligands cause the relative stability of the G-quadruplex, particularly at low temperatures. The calculation of hydrogen bonds in Guanine-tetrads in three different quadruplex sheets shows that the effect of ligands on the sheets is not the same so that the bottom sheet of G-quadruplex is most affected by the ligands at high temperatures, and the Guaninetetrads in this sheet are far away. Conformation factor was calculated as a measure of ligands binding affinity for each of the G-quadruplex residues. Results: The results show that the studied ligands interact more with the G-quadruplex than loop areas, although with increasing temperature, the binding area also includes the G-quadruplex sheets. The contribution of each of the residues involved in the G-quadruplex binding area with ligands was also calculated. Conclusion: The calculations performed are consistent with the previous experimental observations that can help to understand the molecular mechanism of the interaction of phenanthroline and its derivatives with quadruplex.


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