A secreted caspase-3-substrate-cleaving activity at low pH belongs to cathepsin B: a study on primary brain cell cultures.
The cysteine proteases caspase-3 and cathepsins are involved in both neuronal plasticity and neuropathology. Using primary neuroglial and glial cerebellar cultures, the pH dependence of cleavage of a synthetic caspase-3 substrate, Ac-DEVD-AMC, was studied. At acidic pH, cathepsin B cleaved Ac-DEVD, this activity being significantly higher than that of caspase-3 at pH 7.4. This activity is blocked by peptide inhibitors of both caspase-3 and cathepsin B. Substitution of culture medium for balanced salt solution stimulated cathepsin B secretion in both types of cultures. Ischemia (oxygen-glucose deprivation) significantly decreased secretion of cathepsin B activities into the culture medium.
Onufriev
M V
MV
Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, 117485 Moscow, Russia.
Yakovlev
A A
AA
Lyzhin
A A
AA
Stepanichev
M Yu
MY
Khaspekov
L G
LG
Gulyaeva
N V
NV
D000818:Animals; D053148:Caspase 3 / Q000378:metabolism*; D061945:Caspase Inhibitors; D002384:Catalysis / Q000187:drug effects; D002401:Cathepsin B / Q000378:metabolism*; D002474:Cell-Free System / Q000201:enzymology; D002478:Cells, Cultured; D003374:Coumarins / Q000378:metabolism*; D003470:Culture Media / Q000737:chemistry / Q000494:pharmacology; D005947:Glucose / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D009457:Neuroglia / Q000166:cytology / Q000201:enzymology; D009842:Oligopeptides / Q000378:metabolism* / Q000494:pharmacology; D010100:Oxygen / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013379:Substrate Specificity; D013997:Time Factors
C112287:Ac-aspartyl-glutamyl-valyl-aspartyl-aminomethylcoumarin; D061945:Caspase Inhibitors; D003374:Coumarins; D003470:Culture Media; D009842:Oligopeptides; C099158:acetyl-aspartyl-glutamyl-valyl-aspartal; D053148:Caspase 3; D002401:Cathepsin B; D005947:Glucose; D010100:Oxygen