ABSTRACT
Ions can be transported inside our body through cell membrane or through ion channels (Hille, 2001) which may be selective for a specific ion. The function of the cells depends on the functioning of ion channels as they balance the concentration of the electrolytes inside and outside the cells. The channel proteins are surrounded by lipid membrane which separates its internal medium from the external medium and the passage of ions through the ion channel is regulated by the potential difference across the membrane, called membrane potential. Ionic currents perpendicular to the membrane is opposed by a longitudinal current which closes the channel pore after a certain interval. It appears due to the difference of concentration of the ions inside and outside the membrane. There are some specialized proteins which carry ions through the channels. The main groups of ion channels are voltage gated channels, extracellular ligand-activated channels and intracellular ligand-gated ion channels. The main exploration of the ion propagation as a result of action potential was possible by the studies of Hodgkin and Huxley (1952a, 1952b, 1952c, 1952d) with the squid giant axon. Besides these experiments and some other experimental techniques (Doyle et al., 1998; Neher and Sakmann, 1976; Zhou et al., 2001) that revealed the transport mechanism and channel structure, latest development on mathematical models and simulation is observed which relate the molecular structure of channel components to the physiological properties of ion channels. In 1998, Molecular Dynamics (MD) simulation was performed by Zhong et al. (1998) for a synthetic ion channel consisting of four α-helical peptides. Millar et al. (2005) developed a self-consistent particle simulation of ion channels using Poisson and Langevin equations which described the simulation of ion behavior in extremely small pores. An algorithm was developed combining kinetic lattice grand canonical Monte Carlo (MC) simulations and mean field theory by Hwang et al. (2007). The molecular switching mechanism of ion channels can be exploited in the construction of novel biosensors (Christine, 2008; Cornell et al., 1997; Joseph et al., 2003; Krishnamurthy et al., 2010; Urisu et al., 2008).
