Specific interactions between androgen receptor and its ligand: ab initio molecular orbital calculations in water.

The Androgen Receptor (AR) is a family of nuclear receptor proteins and a ligand-activated transcription factor. Since its abnormal activation can cause the progression of prostate cancer, numerous types of antagonists against AR have been developed as promising agents for treating prostate cancers. We here investigated the specific interactions between AR and several types of non-steroid agents at an electronic level, using ab initio molecular simulations based on molecular mechanics and ab initio fragment molecular orbital (FMO) methods From the results obtained by FMO, we proposed novel agents as potent ligands against AR and investigated the binding properties between AR and these agents to confirm that some of them can bind more strongly with AR than the existing non-steroid agents and can be strongly effective ligands against AR.

Specific interactions between zinc metalloproteinase and its inhibitors: Ab initio fragment molecular orbital calculations.

Bacteria secrete the enzyme pseudolysin (PLN) to degrade exocellular proteins, and the produced peptides are used as a nutrient for the bacteria. It is thus expected that inhibition of PLN can suppress bacterial growth. Since such inhibitors do not attack to bacteria directly, the risk of producing drug-resistance bacteria is less.

Specific interactions between vitamin-D receptor and its ligands: Ab initio molecular orbital calculations in water.

Vitamin D is recognized to play important roles not only in the bone metabolism and the regulation of Ca amount in the blood but also in the onset of immunological diseases. These physiological actions caused by vitamin D are triggered by the specific interaction between vitamin D receptor (VDR) and vitamin D. In the present study, we investigated the interactions between VDR and vitamin D derivatives using ab initio molecular simulation, in order to elucidate the reason for the significant difference in their effects on VDR activity.