Simultaneous fluorescent monitoring of proteasomal subunit catalysis.

ABSTRACT: The proteasome, a multicatalytic protease, displays distinct chymotrypsin-like, caspase-like, and trypsin-like activities at three different subunits of the multimeric complex. Fluorescent substrates for each of these active sites have been described. However, since the fluorescent properties of these substrates are very similar, it is not possible to simultaneously monitor catalysis of two or more activities. We have developed a long wavelength (lambda(ex) = 600 nm, lambda(em) = 700 nm) fluorescent substrate for the chymotrypsin-like active site via a combinatorial library strategy. This peptide-based substrate is a highly selective proteasomal chymotrypsin-like sensor, as assessed by a series of proteasomal active site mutants in yeast cell lysates. A corresponding caged analog of the se

SUBMITTER: Wakata A 

PROVIDER: S-EPMC2820722 | biostudies-literature | 2010 Feb

REPOSITORIES: biostudies-literature