1. The Ribosomal Serine Proteinase, Cathepsin R Occurrence in Rat-Liver Ribosomes in a Cryptic Form.
- Author
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Langner, Jürgen, Kirschke, Heidrun, Bohley, Peter, Wiederanders, Bernd, and Korant, Bruce D.
- Subjects
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RIBOSOMES , *PROTEOLYTIC enzymes , *ENDOPEPTIDASES , *LABORATORY rats , *MOLECULAR weights , *SODIUM acetate - Abstract
Ribosomes have been shown to contain a proteolytic activity, characterized as an endopeptidase with serine in the active center. The enzyme has been given the name cathepsin R, following the recommendations of Barrett et al. tin a publication from the Cold Spring Harbor Laboratory, New York) for naming new proteinases. The present paper contains evidence that cathepsin R in rat liver ribosomes is present in a cryptic form. Upon dissociation of ribosomes to subunits (and to minor extent also by 0.5 M KCI washes), the cryptic proteinase is released. Activation of the released cathepsin R is effected by equilibration with 2 M NaCI/0.05 M sodium acetate, pH 4.8. The molecular weight of free cathepsin R is 25000–30000. [ABSTRACT FROM AUTHOR]
- Published
- 1982
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