title: The multicatalytic proteinase complex.
abstract: The multicatalytic proteinase is a soluble nonlysosomal proteinase of Mr congruent to 700,000. It is composed of at least ten different types of subunit arranged as a stack of four rings in a hollow cylindrical structure. It is similar, if not identical, to prosomes and has also been referred to as the proteasome. The proteinase degrades some protein, peptide and synthetic peptide substrates. It is inhibited by thiol-reactive reagents and by peptide aldehydes. Results of studies with these inhibitors and of mixed-substrate experiments suggest that the proteinase molecule has at least two distinct types of proteolytic sites which have different specificities for peptide substrates. Antibodies raised against the native proteinase precipitate the complex but do not inhibit its proteolytic activities, and recognize only a few of the subunits on Western blots.
authors.affiliation: Department of Biochemistry, University of Leicester, U.K.
authors.forename: A J
authors.initials: AJ
authors.lastname: Rivett
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003546:Cysteine Endopeptidases / Q000276:immunology / Q000378:metabolism; D015853:Cysteine Proteinase Inhibitors; D006801:Humans; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000037:antagonists & inhibitors / Q000276:immunology / Q000378:metabolism; D011480:Protease Inhibitors / Q000494:pharmacology; D046988:Proteasome Endopeptidase Complex; D013379:Substrate Specificity
chemical_list: D015853:Cysteine Proteinase Inhibitors; D046911:Macromolecular Substances; D009097:Multienzyme Complexes; D011480:Protease Inhibitors; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex