Identification of 20S proteasome from wheat leaves

FERNÁNDEZ MURRAY P.; GIORDANO C. V.; PASSERON S.; BARNEIX A. J.

Chile

Congreso; VIII PABMB Congress; 1996

The 20S proteasome, also known as multicatalytic proteinase (MCP) is an essential protease found in all eukaryotic organisms and is responsible as the degradative core of the ubiquitin-proteasome pathway of the highly specific degradation of most cytosolic proteins. Recent accumulated evidence indicated that the protein degradation via this pathway is essential in the basic regulation of the cellular metabolism. In order to initiate the study of the role of this proteolytic system in wheat leaf senescence process, the 20 S proteasome from this source was purified to near homogeneity by DEAE-Sephacel, Q- Sepharose, Sepharose and hydroxilapatite column chromatography. Substrate specificity and inhibition/activation studies as well as structural characterization of the enzyme (native and SDS-PAGE; 2D electrophoresis, electronic microscopy) show the wheat 20S proteasome possess the canonical features of this conserved proteinase.