Inhibitors of inosine monophosphate dehydrogenase as potential chemotherapeutic agents

Inosine monophosphate dehydrogenase (IMPDH, E.C.1.1.1.205), an NAD-dependen t enzyme that controls de novo synthesis of purine nucleotides, is an impor tant target for the development of chemotherapeutic agents. The concentrati on of IMPDH is known to increase in tumour cells and activated lymphocytes. Thus, inhibition of IMPDH should result in anticancer and immunosuppressiv e activities. Since there is an increased demand for purine nucleotides in virus-infected cells needed for RNA and DNA synthesis, inhibition of IMPDH may also lead to antiviral activity. IMPDH enzymes from bacteria, parasites and mammalian sources differ significantly. Such differences can be exploi ted for the development of antibacterial or antiparasitic agents. A review, which covers the development of the field up to 1998, was published in thi s Journal [Pankiewicz KW, Expert Opin. Ther. Patents (1999) 9(1):55-65]. Th is article describes recent studies of molecular structure, mechanism of ac tion and interactions of the enzyme with the co-factor and inhibitors. Pers pectives on the development of a new generation of potent and specific inhi bitors of IMPDH based on these accomplishments are discussed.