Two secreted acid phosphatases (SAP1 and SAP2) were markedly up-regulated during Pi-starvation of tomato suspension and SAP2 were resolved during cat-ion-exchange FPLC of culture media proteins from 8-day-old Pi -starved cells, and purified to homogeneity and final p-nitrophenylphosphatehydrolyzing specificactivitiesof 246 and 940lmol Pi producedÆmin )1 mgÆprotein )1 , , periodic acid-Schiff staining and analyt-ical gel filtration demonstrated that SAP1 and SAP2, respectively, exist as 84 and57 kDa glycosylatedmonomers
