Here I introduce some examples of molecular structures related to disease therapy. One is oseltamivir which is also given the trade name Tamiflu. The important processes of influenza infection are to ENTER the host cell and to GO OUT from it, and some of the antiviral medicines target these processes. The enzyme neuraminidase clips off a sialic acid from the cell membrane to assist the replicated viruses to go out. Tamiflu is a molecule with a similar structure to it which also binds to neuraminidase, and inhibits the enzyme function (Figure 1). In the case of mutant enzyme (H274Y), Tamiflu binds to it weaker than the wild type, so Tamiflu has less effect than the mutant type. The replaced 274th residue tyrosine is bulkier than the original amino acid histidine and causes orientation change of the amino acid at the active site (Figure 2). Another example is involved in Ebolavirus causing epidemics in West Africa. Although the effective therapeutic medicine and vaccine have not been found yet, the molecular structure of the antibody complex with virus glycoprotein from a human survivor is already deposited to PDB (Figure 3). Now scientists are searching for some effective chemicals and methods using this information.
A simple, universal equation of state (EOS) for hydrocarbons is proposed. This EOS allows estimation of the effective potential parameters ε and σ in the Lennard-Jones function as analytic functions of n, the number of electrons in the hydrocarbon molecule. Using these parameters, the thermodynamic properties of hydrocarbons may be calculated based on the EOS for a perfect liquid, as already proposed in the Lennard-Jones system. The thermodynamic properties estimated in this manner for various hydrocarbons have been found to be reasonably similar to experimentally obtained values.