Abstract: | Western immunoblot analysis of protein extracts prepared from epidermal peels, whole leaves, and mesophyll protoplasts with ubiquitin and PEPCase antibodies indicated ubiquitinated PEPCase bands and degradation products only in crude extracts which have been obtained in the presence of the proteolysis inhibitors leupeptin and hemin. After ammonium sulfate precipitation and further purification, PEPCase forms were stable and not ubiquitinated. It is assumed, that only a certain part of PEPCase is degraded via the ubiquitin-dependent proteolysis. |