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Maturation and degradation of β‐galactosidase in the post‐Golgi compartment are regulated by cathepsin B and a non‐cysteine protease
Author(s) -
Okamura-Oho Yuko,
Zhang Sunqu,
Callahan John W,
Murata Mitsuo,
Oshima Akihiro,
Suzuki Yoshiyuki
Publication year - 1997
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(97)01461-0
Subject(s) - cathepsin b , cysteine protease , cathepsin , protease , biochemistry , cathepsin l , cysteine , chemistry , lysosome , cathepsin o , enzyme , cathepsin c , proteases , cathepsin h , cathepsin d , proteolysis , protein degradation
Lysosomal β‐galactosidase precursor is processed to a mature form and associated with protective protein in lysosomes. In this study we used two cysteine protease proinhibitors, E64‐d for cathepsins B, S, H, and L, and CA074Me for cathepsin B. They are converted intracellularly to active forms, E‐64c and CA074, respectively. Both active compounds inhibited maturation of the exogenous β‐galactosidase precursor, but E‐64c did not inhibit further degradation to an inactive 50‐kDa product. We concluded that cathepsin B participated exclusively in maturation of β‐galactosidase, and a non‐cysteine protease was involved in further degradation and inactivation of the enzyme molecule.