Identification of Targets of the HIF-1 Inhibitor IDF-11774 Using Alkyne-Conjugated Photoaffinity Probes

Hyun Seung Ban, Ravi Naik, Hwan Mook Kim, Bo Kyung Kim, Hongsub Lee, Inhyub Kim, Heechul Ahn, Yerin Jang, Kyusik Jang, Yumi Eo, Kyung Bin Song, Kyeong Lee, Misun Won

Research output: Contribution to journalArticlepeer-review

29 Scopus citations

Abstract

We developed a hypoxia-inducible factor-1 (HIF-1) inhibitor, IDF-11774, as a clinical candidate for cancer therapy. To understand the mechanism of action of IDF-11774, we attempted to isolate target proteins of IDF-11774 using bioconjugated probes. Multifunctional chemical probes containing sites for click conjugation and photoaffinity labeling were designed and synthesized. After fluorescence and photoaffinity labeling of proteins, two-dimensional electrophoresis (2DE) was performed to isolate specific molecular targets of IDF-11774. Heat shock protein (HSP) 70 was identified as a target protein of IDF-11774. We revealed that IDF-11774 inhibited HSP70 chaperone activity by binding to its allosteric pocket, rather than the ATP-binding site in its nucleotide-binding domain (NBD). Moreover, IDF-11774 reduced the oxygen consumption rate (OCR) and ATP production, thereby increasing intracellular oxygen tension. This result suggests that the inhibition of HSP70 chaperone activity by IDF-11774 suppresses HIF-1α refolding and stimulates HIF-1α degradation. Taken together, these findings indicate that IDF-11774-derived chemical probes successfully identified IDF-11774's target molecule, HSP70, and elucidated the mode of action of IDF-11774 in inhibiting HSP70 chaperone activity and stimulating HIF-1α degradation in cancer cells.

Original languageEnglish
Pages (from-to)1911-1920
Number of pages10
JournalBioconjugate Chemistry
Volume27
Issue number8
DOIs
StatePublished - 17 Aug 2016

Fingerprint

Dive into the research topics of 'Identification of Targets of the HIF-1 Inhibitor IDF-11774 Using Alkyne-Conjugated Photoaffinity Probes'. Together they form a unique fingerprint.

Cite this