title: Brain cathepsin B cleaves a caspase substrate.
abstract: We show that an enzyme exists in rat brain capable of cleaving the caspase-3 specific peptide substrate Ac-DEVD-AMC at low pH. The enzyme shows properties of a cysteine protease and is localized, predominantly, in lysosomes. We have purified this enzyme from rat brain and identified it by MALDI-TOF MS. The enzyme possessing "acidic" DEVDase activity in rat brain appears to be cathepsin B. It remains obscure, whether cathepsin B participates in cleavage of caspase-3 substrates in vivo. We suggest that under certain conditions (e.g. in hypoxia) cathepsin B participates in cleavage of caspase-3 substrates in brain cells.
authors.affiliation: Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, Russia.
authors.forename: A A
authors.initials: AA
authors.lastname: Yakovlev
authors.forename: A Yu
authors.initials: AY
authors.lastname: Gorokhovatsky
authors.forename: M V
authors.initials: MV
authors.lastname: Onufriev
authors.forename: I P
authors.initials: IP
authors.lastname: Beletsky
authors.forename: N V
authors.initials: NV
authors.lastname: Gulyaeva
mesh_terms: D000818:Animals; D001921:Brain / Q000201:enzymology*; D053148:Caspase 3 / Q000378:metabolism*; D002401:Cathepsin B / Q000302:isolation & purification / Q000378:metabolism*; D003374:Coumarins / Q000378:metabolism; D015853:Cysteine Proteinase Inhibitors / Q000378:metabolism / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D009842:Oligopeptides / Q000378:metabolism; D051381:Rats; D013439:Sulfhydryl Reagents / Q000494:pharmacology
chemical_list: C112287:Ac-aspartyl-glutamyl-valyl-aspartyl-aminomethylcoumarin; D003374:Coumarins; D015853:Cysteine Proteinase Inhibitors; D009842:Oligopeptides; D013439:Sulfhydryl Reagents; D053148:Caspase 3; D002401:Cathepsin B