Fungal metabolite, epoxyquinol B, crosslinks proteins by epoxy-thiol conjugation.
Epoxyquinol B (EPQB) is a fungal metabolite, containing two alpha,beta-epoxy ketones. We previously showed that EPQB inhibited the signal transduction involved in angiogenesis through the binding to cysteine residues of receptor kinases. However, the inhibitory mechanism was undefined. In this report, we found that one EPQB molecule is covalently bound to two L-cysteine molecules through two epoxide residues on EPQB. Furthermore, EPQB crosslinked binding proteins through the cysteine residues. These results suggest that EPQB inhibits receptor kinases by crosslinking with other protein or by intramolecular crosslinking.
Kamiyama
Hiroshi
H
Antibiotics Laboratory, RIKEN Discovery Research Institute, Hirosawa, Wako, Saitama, Japan..
Usui
Takeo
T
Uramoto
Masakazu
M
Takagi
Hiroshi
H
Shoji
Mitsuru
M
Hayashi
Yujiro
Y
Kakeya
Hideaki
H
Osada
Hiroyuki
H
D002851:Chromatography, High Pressure Liquid; D003432:Cross-Linking Reagents / Q000737:chemistry; D003545:Cysteine / Q000737:chemistry*; D004852:Epoxy Compounds / Q000737:chemistry*; D006873:Hydroquinones / Q000737:chemistry*; D015394:Molecular Structure
D003432:Cross-Linking Reagents; D004852:Epoxy Compounds; D006873:Hydroquinones; C469247:epoxyquinol B; D003545:Cysteine