The ATP/Mg2+ Balance Affects the Degradation of Short Fluorogenic Substrates by the 20S Proteasome.

ABSTRACT: Proteasomes hydrolyze most cellular proteins. The standard reaction to determine proteasome activity in cellular lysate or elsewhere contains AMC-conjugated peptide substrate, ATP, Mg2+, and DTT. ATP and Mg2+ are included to maintain 26S proteasome functionality. However, most cellular proteasomes are 20S proteasomes, and the effects of ATP on the turnover of fluorogenic substrates by 20S complexes are largely unknown. Here, we evaluated the effect of ATP alone or in combination with Mg2+ on the degradation of AMC-conjugated fluorogenic substrates by purified 20S proteasomes. Degradation of substrates used to determine chymotrypsin-, caspase- and trypsin-like proteasome activities was gradually decreased with the rise of ATP concentration from 0.25 to 10 mM. These effects were not associat

SUBMITTER: Morozov A 

PROVIDER: S-EPMC8875927 | biostudies-literature | 2022 Feb

REPOSITORIES: biostudies-literature