Structural insights into the binding mechanism of IDO1 with hydroxylamidine based inhibitor INCB14943

Journal Article · Sat May 27 04:00:00 EDT 2017 · Biochemical and Biophysical Research Communications

DOI:https://doi.org/10.1016/J.BBRC.2017.04.061· OSTI ID:22697031

Wu, You ^[1]; Xu, Tingting ^[2]; Liu, Jinsong ^[2]; Ding, Ke ^[1]; Xu, Jinxin ^[2]

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1. Institute of Medicinal Chemistry and Biology, College of Pharmacy, Jinan University, Guangzhou (China)
2. State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530 (China)

IDO1 (indoleamine 2, 3-dioxygenase 1), a well characterized immunosuppressive enzyme, has attracted growing attention as a potential target for cancer immunotherapy. Hydroxylamidine compounds INCB024360 and INCB14943 (INCB024360 analogue) are highly effective IDO1 inhibitors. INCB024360 is undergoing clinical trials for treatment of various types of human cancer. Here, we determined the co-crystal structure of IDO1 and INCB14943, and elucidate the detailed binding mode. INCB14943 binds to heme iron in IDO1 protein through the oxime nitrogen. Further analysis also reveals that a halogen bonding interaction between the chlorine atom (3-Cl) of INCB14943 and the sulphur atom of C129 significantly improves the inhibition activity against IDO1. Comparing with the other reported inhibitors, the oxime nitrogen and halogen bond interaction are identified as the unique features of INCB14943 among the IDO1 inhibitors. Thus, our study provides novel insights into the interaction between a small molecule inhibitor INCB14943 and IDO1 protein. The structural information will facilitate future IDO1 inhibitor design. - Highlights: • This is the first co-crystal structure of IDO1 with hydroxylamidine compound. • INCB14943 binds to heme iron through oxime nitrogen instead of imidazole nitrogen. • Halogen bond interaction with C129 is another unique feature of INCB14943.

• OSTI ID: 22697031
• Journal Information: Biochemical and Biophysical Research Communications, Journal Name: Biochemical and Biophysical Research Communications Journal Issue: 2 Vol. 487; ISSN 0006-291X; ISSN BBRCA9
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
BONDING
CLINICAL TRIALS
INHIBITION
INTERACTIONS
NITROGEN