Discovery of Novel Allosteric Inhibitors of Deoxyhypusine Synthase.
Tanaka, Y., Kurasawa, O., Yokota, A., Klein, M.G., Ono, K., Saito, B., Matsumoto, S., Okaniwa, M., Ambrus-Aikelin, G., Morishita, D., Kitazawa, S., Uchiyama, N., Ogawa, K., Kimura, H., Imamura, S.(2020) J Med Chem 63: 3215-3226
- PubMed: 32142284 
- DOI: https://doi.org/10.1021/acs.jmedchem.9b01979
- Primary Citation of Related Structures:  
6P4V, 6PGR - PubMed Abstract: 
Deoxyhypusine synthase (DHPS) utilizes spermidine and NAD as cofactors to incorporate a hypusine modification into the eukaryotic translation initiation factor 5A (eIF5A). Hypusine is essential for eIF5A activation, which, in turn, plays a key role in regulating protein translation of selected mRNA that are associated with the synthesis of oncoproteins, thereby enhancing tumor cell proliferation. Therefore, inhibition of DHPS is a promising therapeutic option for the treatment of cancer. To discover novel lead compounds that target DHPS, we conducted synthetic studies with a hit obtained via high-throughput screening. Optimization of the ring structures of the amide compound ( 2 ) led to bromobenzothiophene ( 11g ) with potent inhibitory activity against DHPS. X-ray crystallographic analysis of 11g complexed with DHPS revealed a dramatic conformational change in DHPS, which suggests the presence of a novel allosteric site. These findings provide the basis for the development of novel therapy distinct from spermidine mimetic inhibitors.
Organizational Affiliation: 
Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan.