A. V. Bacheva, O. V. Korobkina, P. S. Nesterova, V. A. Kryachkov, A. G. Gabibov
11S Proteasome activator: isolation from
mice brain and influence on peptide substrate hydrolysis by 20S and 26S proteasome
Abstract
Purification of 11S proteasome regulator
from mice brain was optimized; subunit composition of isolated protein was
determined by Western-blot. The dependency of peptidase activity of 20S
proteasome on molar concentration of 11S regulator was examined. Michaelis
constants of hydrolysis of specific fluorescent substrates
Suc-Leu-Leu-Val-Tyr-AMC, Ac-Arg-Leu-Arg-AMC, Z-Leu-Leu-Glu-AMC by 20S
proteasome from BALB/c mice brain and by 20S-11S complex. It was shown that 11S
subparticle has almost no influence on binding of specific fluorescent
substrates by 20S proteasome, but strongly accelerates hydrolysis of all three
substrates. At the same conditions 11S proteasome regulator did not change
kinetic parameters for 26S proteasome.
Key words: proteasome, 11S proteasome
regulator, proteasome activity, subunit composition.
Copyright (C) Chemistry Dept., Moscow State University, 2002
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