Open AccessThe Ribosomal Serine Proteinase, Cathepsin R
Author(s) -
LANGNER Jüurgen,
KIRSCHKE Heidrun,
BOHLEY Peter,
WIEDERANDERS Bernd,
KORANT Bruce D.
Publication year - 1982
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1982.tb06645.x
Subject(s) - ribosome , biochemistry , ribosomal rna , serine , cathepsin , ribosomal protein , cathepsin o , enzyme , chemistry , biology , endopeptidase , microbiology and biotechnology , rna , gene
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. (in a publication from the Cold Spring Harbor Laboratory, New York) for naming new pro‐ teinases. 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 KCl washes). the cryptic proteinase is released. Activation of the released cathepsin R is effected by equilibration with 2 MNaCl/O.05 M sodium acetate, pH 4.8. The molecular weight of free cathepsin R is 25000–30000.