STRUCTURE AND FUNCTION OF CHLOROPLAST PROTEINS .7. RIBULOSE-1,5-DIPHOSPHATE CARBOXYLASE OF CHLORELLA ELLIPSOIDEA

Ribulose-1, 5-diphosphate carboxylase isolated from autotrophically grown cells of the green algae, Chlorella ellipsoidea, was partially purified. The nature of the enzyme closely resembles the spinach leaf enzyme in its elution patterns on Sephadex gel filtration and DEAE-cellulose column chromatography, migration on starch gel electrophoresis, and the immunological specificity. Chlorella RuDP carboxylase exhibits essentially identical kinetic parameters of the regulatory enzyme with those of spinach enzyme: (a) homotropic effect of NaHCO3, (b) allosteric activating effect of Mg2+ with respect to NaHCO3, and (c) shift of optimum pH by elevating the Mg2+ concentrations. © 1969.