title: 'Chymotrypsin-like' activity of chicken liver multicatalytic proteinase resides in the smallest subunit.
abstract: 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.
authors: Mitsubishi-Kasei Institute of Life Sciences, Tokyo, Japan.
authors: S
authors: S
authors: Sato
authors: A
authors: A
authors: Shiratsuchi
mesh_terms: 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
chemical_list: D009097:Multienzyme Complexes; D007531:Isoflurophate; D002918:Chymotrypsin; D014357:Trypsin; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex