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Na + , K + ‐specific inhibition of protein and peptide hydrolyses by proteasomes from human hepatoma tissues
Author(s) -
Seol Jae Hong,
Park Sang Chul,
Ha Doo Bong,
Chung Chin Ha,
Tanaka Keiji,
Ichihara Akira
Publication year - 1989
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 - 10.1016/0014-5793(89)81333-x
Subject(s) - polylysine , chemistry , proteasome , peptide , intracellular , casein , biochemistry , hydrolysis , microbiology and biotechnology , biology
Proteasomes were purified from human hepatoma tissues, and their sensitivities to Na + and K + were examined. At concentrations of 10 mM or more, these cations were found to inhibit completely polylysine‐activated casein degradation by the purified proteasomes. They also strongly inhibited the hydrolyses of peptides, although to a lesser extent. On the other hand, they reversed the inhibitory and stimulatory effects of polylysine on the hydrolyses of Suc‐Leu‐Tyr‐AMC and Cbz‐Ala‐Arg‐Arg‐MNA, respectively. These results suggest that Na + and/or K + may be involved in the regulation of intracellular protein breakdown by controlling the multicatalytic activity of proteasomes.