Calcium-activated neutral protease (CANP), a putative processing enzyme of the neuropeptide, kyotorphin, in the brain.
Kyotorphin (Tyr-Arg) accumulation in the dialysed synaptosol from the rat brain in the presence of an inhibitor of kyotorphin-degrading enzyme, was maximal at neutral pH. This accumulation was activated by calcium ions, but was inhibited by leupeptin and SH-blocking agents, a finding which suggests the involvement of calcium-activated neutral protease (CANP or calpain). In addition, the kyotorphin-precursor protein, being processed by purified mu- or m-CANP, was detected at about 160 kDa on Sephacryl S-300 chromatography of the synaptosol. The present findings seem to be the first evidence for the role of CANP as a processing enzyme of neuropeptide-precursor in nerve terminals.
Yoshihara
Y
Y
Department of Pharmacology, Faculty of Pharmaceutical Sciences, Kyoto University, Japan.
Ueda
H
H
Imajoh
S
S
Takagi
H
H
Satoh
M
M
D000818:Animals; D001921:Brain / Q000201:enzymology*; D002118:Calcium / Q000494:pharmacology; D002154:Calpain / Q000378:metabolism*; D004723:Endorphins / Q000096:biosynthesis*; D006863:Hydrogen-Ion Concentration; D007930:Leucine / Q000031:analogs & derivatives / Q000494:pharmacology; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013439:Sulfhydryl Reagents / Q000494:pharmacology; D013574:Synaptosomes / Q000201:enzymology; D013997:Time Factors
D004723:Endorphins; D013439:Sulfhydryl Reagents; C019448:kyotorphin; D002154:Calpain; D007930:Leucine; C012211:ubenimex; D002118:Calcium