'Chymotrypsin-like' activity of chicken liver multicatalytic proteinase resides in the smallest subunit.
Chicken liver multicatalytic proteinase is composed of multiple components with molecular masses ranging from 23 to 34 kDa and has 'chymotrypsin-like' and 'trypsin-like' activities, which were examined by using the chromogenic peptide substrates, succinyl-Phe-Leu-Phe-pNA(p-nitroanilide) and N-benzoyl-Phe-Val-Arg-pNA, respectively. Treatment of the enzyme with diisopropyl fluorophosphate (DFP) completely abolished the 'chymotrypsin-like' activity, but had little effect on the 'trypsin-like' activity. In the experiment with radio-labeled DFP, SDS-PAGE of the modified enzyme revealed that the radioactivity was incorporated into only the smallest subunit (23 kDa). The migration of this subunit was retarded on SDS-PAGE after the treatment with DFP.
Sato
S
S
Mitsubishi-Kasei Institute of Life Sciences, Tokyo, Japan.
Shiratsuchi
A
A
D000595:Amino Acid Sequence; D000818:Animals; D002645:Chickens; D002851:Chromatography, High Pressure Liquid; D002918:Chymotrypsin / Q000378:metabolism*; D003546:Cysteine Endopeptidases / Q000302:isolation & purification / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D006863:Hydrogen-Ion Concentration; D007531:Isoflurophate / Q000494:pharmacology; D008099:Liver / Q000201:enzymology*; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000302:isolation & purification / Q000378:metabolism*; D046988:Proteasome Endopeptidase Complex; D013379:Substrate Specificity; D014357:Trypsin / Q000378:metabolism
D009097:Multienzyme Complexes; D007531:Isoflurophate; D002918:Chymotrypsin; D014357:Trypsin; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex