We currently study the determinants of conductance and selectivity of ion channels. We have recently proposed a new mechanism of how sodium channels prefer sodium vs potassium. If you are interested check out these papers:<\/p>\n Ion channel selectivity through ion-modulated changes of selectivity filter pK<\/i>a<\/sub>\u00a0values<\/a>, PNAS 120 (26), e2220343120<\/p>\n Characterizing the Ion-Conductive State of the \u03b17-Nicotinic Acetylcholine Receptor via Single-Channel Measurements and Molecular Dynamics Simulations<\/a><\/p>\n We investigate how the physical properties of ion channels shape electrical activity in neurons and lay the groundwork for understanding collective dynamics in neural circuits. By integrating molecular-scale simulations with models of neuronal excitability, we explore how channel kinetics, electrostatics, and thermal fluctuations influence single-neuron behavior. This multi-scale approach connects atomic biophysics to cellular and systems neuroscience, bridging theory, computation, and experiment. Our goal is to uncover the physical principles linking molecular events to emergent neural function.<\/p>\n Please check out our recent paper:<\/p>\n![\"ion](\"https:\/\/sites.krieger.jhu.edu\/damjanovic-lab\/files\/2021\/01\/Screen-Shot-2021-01-07-at-1.26.24-PM-300x234.png\")
Ion channels are membrane proteins that form pores and control the flow of ions across cell membranes. They are found in virtually all living cells, and have tremendous physiological relevance in regulating ion concentrations inside cells. In the brain and the heart, ion channels are key players in generation of exotic phenomena known as action potentials. Selectivity of ion channels for one ion type\u00a0<\/span>is key, as the action potential occurs through rapid opening and closing of voltage dependent sodiu<\/span>m selective channels, and potassium selective channels.<\/span><\/p>\nFrom Channels to Neural Circuits<\/strong><\/h3>\n
![\"Aspartic](\"https:\/\/sites.krieger.jhu.edu\/damjanovic-lab\/files\/2021\/01\/Screen-Shot-2021-01-07-at-2.08.30-PM-300x106.png\")
Binding of protons to ionizable amino acids in proteins, such as aspartic and glutamic acid, histidine and lysine affects the charge on that residue and thus determines the protein’s electrostatic properties. Electrostatics affects almost every structural and functional aspect of proteins; including stability, solubility, dynamics, interactions, and catalysis. It is especially important for key processes involving movement of charges, including proton and electron transfer reactions and transport of ions. Thus it is very important to know how many protons are bound to a protein, and to which ionizable residues, i.e., it is important to know what the protonation state of each ionizable residue is.<\/p>\n