Open Access. Powered by Scholars. Published by Universities.®

Physics Commons

Open Access. Powered by Scholars. Published by Universities.®

Clemson University

Publications

PKa calculations

Publication Year

Articles 1 - 4 of 4

Full-Text Articles in Physics

The Role Of Protonation States In Ligand-Receptor Recognition And Binding, Marharyta Petukh, Shannon Stefl, Emil Alexov May 2013

The Role Of Protonation States In Ligand-Receptor Recognition And Binding, Marharyta Petukh, Shannon Stefl, Emil Alexov

Publications

In this review we discuss the role of protonation states in receptor-ligand interactions, providing experimental evidences and computational predictions that complex formation may involve titratable groups with unusual pKa’s and that protonation states frequently change from unbound to bound states. These protonation changes result in proton uptake/release, which in turn causes the pHdependence of the binding. Indeed, experimental data strongly suggest that almost any binding is pH-dependent and to be correctly modeled, the protonation states must be properly assigned prior to and after the binding. One may accurately predict the protonation states when provided with the structures of the unbound …


In Silico Investigation Of Ph-Dependence Of Prolactin And Human Growth Hormone Binding To Human Prolactin Receptor, Lin Wang, Shawn Witham, Zhe Zhang, Michael E. Hodsdon, Emil Alexov Jan 2013

In Silico Investigation Of Ph-Dependence Of Prolactin And Human Growth Hormone Binding To Human Prolactin Receptor, Lin Wang, Shawn Witham, Zhe Zhang, Michael E. Hodsdon, Emil Alexov

Publications

Experimental data shows that the binding of human prolactin (hPRL) to human prolactin receptor (hPRLr-ECD) is strongly pH-dependent, while the binding of the same receptor to human growth hormone (hGH) is pH-independent. Here we carry in silico analysis of the molecular effects causing such a difference and reveal the role of individual amino acids. It is shown that the computational modeling correctly predicts experimentally determined pKa’s of histidine residues in an unbound state in the majority of the cases and the pH-dependence of the binding free energy. Structural analysis carried in conjunction with calculated pH-dependence of the binding revealed that …


Developing Hybrid Approaches To Predict Pka Values Of Ionizable Groups, Shawn Witham, Kemper Talley, Lin Wang, Zhe Zhang, Daquan Gao, Wei Yang, Emil Alexov Dec 2011

Developing Hybrid Approaches To Predict Pka Values Of Ionizable Groups, Shawn Witham, Kemper Talley, Lin Wang, Zhe Zhang, Daquan Gao, Wei Yang, Emil Alexov

Publications

Accurate predictions of pKa values of titratable groups require taking into account all relevant processes associated with the ionization/deionization. Frequently, however, the ionization does not involve significant structural changes and the dominating effects are purely electrostatic in origin allowing accurate predictions to be made based on the electrostatic energy difference between ionized and neutral forms alone using a static structure. On another hand, if the change of the charge state is accompanied by a structural reorganization of the target protein, then the relevant conformational changes have to be taken into account in the pKa calculations. Here we report a hybrid …


A Missense Mutation In Clic2 Associated With Intellectual Disability Is Predicted By In Silico Modeling To Affect Protein Stability And Dynamics, Shawn Witham, Kyoko Takano, Charles Schwartz, Emil Alexov Aug 2011

A Missense Mutation In Clic2 Associated With Intellectual Disability Is Predicted By In Silico Modeling To Affect Protein Stability And Dynamics, Shawn Witham, Kyoko Takano, Charles Schwartz, Emil Alexov

Publications

Large-scale next generation resequencing of X chromosome genes identified a missense mutation in the CLIC2 gene on Xq28 in a male with X-linked intellectual disability (XLID) and not found in healthy individuals. At the same time, numerous nsSNPs (nonsynonomous SNP) have been reported in the CLIC2 gene in healthy individuals indicating that the CLIC2 protein can tolerate amino acid substitutions and be fully functional. To test the possibility that p.H101Q is a disease-causing mutation, we performed in silico simulations to calculate the effects of the p.H101Q mutation on CLIC2 stability, dynamics, and ionization states while comparing the effects obtained for …