title: Purification and characterization of a multicatalytic proteinase from Atlantic salmon (Salmo salar) muscle.
abstract: A high molecular mass alkaline proteinase was purified by DEAE-Sepharose and Mono Q chromatography. The mol. wt was estimated to be about 600,000. Under denaturing conditions, the enzyme dissociated into a cluster of subunits with mol. wt ranging from 25,000 to 30,000. The isoelectric point of the enzyme was about pH 7.3. The proteinase was able to hydrolyse N-terminal-blocked 4-methyl-7-coumarylamide substrates for either trypsin- or chymotrypsin-like activity. It was also able to hydrolyse haemoglobin and myosin at temperatures of about 60 degrees C. The activities responded to pH and some chemicals in different ways. The trypsin-like activity was clearly inhibited by several serine protease inhibitors. These results suggest that the enzyme is multicatalytic, having at least two different active sites.
authors.affiliation: Department of Biotechnology, Norwegian Institute of Technology, University of Trondheim.
authors.forename: I
authors.initials: I
authors.lastname: Stoknes
authors.forename: T
authors.initials: T
authors.lastname: Rustad
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D003546:Cysteine Endopeptidases / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents / Q000737:chemistry / Q000494:pharmacology; D008297:Male; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism; D009124:Muscle Proteins / Q000378:metabolism; D018482:Muscle, Skeletal / Q000737:chemistry / Q000201:enzymology*; D009210:Myofibrils / Q000737:chemistry / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex; D012474:Salmon / Q000502:physiology*; D013379:Substrate Specificity
chemical_list: D007202:Indicators and Reagents; D009097:Multienzyme Complexes; D009124:Muscle Proteins; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex