title: Fungal metabolite, epoxyquinol B, crosslinks proteins by epoxy-thiol conjugation.
abstract: 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.
authors.affiliation: Antibiotics Laboratory, RIKEN Discovery Research Institute, Hirosawa, Wako, Saitama, Japan..
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kamiyama
authors.forename: Takeo
authors.initials: T
authors.lastname: Usui
authors.forename: Masakazu
authors.initials: M
authors.lastname: Uramoto
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Takagi
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Shoji
authors.forename: Yujiro
authors.initials: Y
authors.lastname: Hayashi
authors.forename: Hideaki
authors.initials: H
authors.lastname: Kakeya
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Osada
mesh_terms: 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
chemical_list: D003432:Cross-Linking Reagents; D004852:Epoxy Compounds; D006873:Hydroquinones; C469247:epoxyquinol B; D003545:Cysteine