Download MendeleyStructure-guided development of a potent human B 0 AT1 inhibitor effective in a mouse model of phenylketonuria.
Imazu, T., Akashi, T., Hiraizumi, M., Inui, Y., Sasaki, W., Takahashi, T., Todoroki, H., Kumanomidou, T., Yamada, K., Fujikawa, N., Hisano, H., Asada, H., Kusakizako, T., Nishizawa, T., Iwata, S., Nureki, O., Miyaguchi, I.(2026) Commun Biol
- PubMed: 42350764 Search on PubMed
- DOI: https://doi.org/10.1038/s42003-026-10535-y
- Primary Citation Related Structures:
9KXT, 9KXU, 9KXV, 9KXW, 9KXX, 9KXY, 9KXZ, 9KY0, 9KY1, 9LSZ - PubMed Abstract:
B 0 AT1 (SLC6A19) is a neutral amino acid transporter mediating intestinal absorption and renal reuptake of amino acids, including phenylalanine (Phe). Inhibiting B 0 AT1 enhances Phe excretion, offering a therapeutic strategy for phenylketonuria (PKU). Using cryo-EM, we determined human B 0 AT1 structures in outward- and inward-open states, revealing an allosteric pocket ~17 Å from the substrate site that is present in the outward-open conformation and has been previously reported. Structure-guided inhibitor design targeting this pocket produced a potent B 0 AT1 inhibitor that locks the transporter in an outward-occluded state and blocks transport. The higher-resolution structures reveal detailed interactions at the binding site, including water-mediated coordination and conformational changes around Leu52. This inhibitor exhibited submicromolar IC 50 against both human and mouse B 0 AT1, and oral administration in PKU model mice increased urinary Phe and reduced plasma Phe levels. These findings provide structural insight into allosteric inhibition of B 0 AT1 and establish a framework for the rational optimization of inhibitors targeting conformationally dynamic allosteric sites in SLC6-family transporters.
- Neuro Science Unit Sohyaku Innovative Research Division, Mitsubishi Tanabe Pharma Co., Ltd., Yokohama, Japan. 0389158@mt-pharma.co.jp.
Organizational Affiliation:
