Discovery of a Kelch-like ECH-associated protein 1-inhibitory tetrapeptide and its structural characterization.
Keap1 constitutively binds to the transcription factor Nrf2 to promote its degradation, resulting in negative modulation of genes involved in cellular protection against oxidative stress. Keap1 is increasingly recognized as an attractive target for treating diseases involving oxidative stress, including cancer, atherosclerosis, diabetes, arthritis, and neurodegeneration. We used phage-display peptide screening to identify a tetrapeptide showing moderate binding affinity, which inhibits the interaction between Nrf2 and Keap1. The tetrapeptide does not include an ETGE motif, which is a commonly found consensus sequence in known peptidic inhibitors. In addition to affinity parameters, IC50, KD, and thermodynamic parameters, the crystal structure of the complex was determined to elucidate the binding conformation. The binding interactions resemble those of known small-molecule inhibitors as opposed to those of substrates and peptidic inhibitors. Although the tetrapeptide's affinity is not very high, our results may help facilitate the designing of small-molecule inhibitors during lead generation in drug discovery.
Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-Chome, Fujisawa, Kanagawa 251-8555, Japan. Electronic address: satoshi.sogabe@takeda.com.
Satoshi
S
Sogabe
Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-Chome, Fujisawa, Kanagawa 251-8555, Japan.
Kotaro
K
Sakamoto
Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-Chome, Fujisawa, Kanagawa 251-8555, Japan.
Yusuke
Y
Kamada
Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-Chome, Fujisawa, Kanagawa 251-8555, Japan.
Akito
A
Kadotani
Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-Chome, Fujisawa, Kanagawa 251-8555, Japan.
Yasunori
Y
Fukuda
Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-Chome, Fujisawa, Kanagawa 251-8555, Japan.
Jun-Ichi
JI
Sakamoto
D020816:Amino Acid Motifs; D001665:Binding Sites; D003001:Cloning, Molecular; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D006801:Humans; D000072019:Kelch-Like ECH-Associated Protein 1 / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000235:genetics; D007700:Kinetics; D008958:Models, Molecular; D051267:NF-E2-Related Factor 2 / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000235:genetics; D009842:Oligopeptides / Q000138:chemical synthesis / Q000737:chemistry*; D019151:Peptide Library; D011485:Protein Binding; D000072417:Protein Domains; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics; D013816:Thermodynamics
C431364:KEAP1 protein, human; D000072019:Kelch-Like ECH-Associated Protein 1; D051267:NF-E2-Related Factor 2; C495635:NFE2L2 protein, human; D009842:Oligopeptides; D019151:Peptide Library; D011994:Recombinant Proteins
Keap1; Nrf2; Peptidic inhibitor; Phage display; Protein–protein interaction; X-ray crystallography