Brain cathepsin B cleaves a caspase substrate.
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.
Yakovlev
A A
AA
Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, Russia.
Gorokhovatsky
A Yu
AY
Onufriev
M V
MV
Beletsky
I P
IP
Gulyaeva
N V
NV
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
C112287:Ac-aspartyl-glutamyl-valyl-aspartyl-aminomethylcoumarin; D003374:Coumarins; D015853:Cysteine Proteinase Inhibitors; D009842:Oligopeptides; D013439:Sulfhydryl Reagents; D053148:Caspase 3; D002401:Cathepsin B