Ribulose 1,5-diphosphate carboxylase from Oenothera. Purification and a peptide mapping procedure for the subunits

Research paper by Anthony A. Holder

Indexed on: 01 Nov '76Published on: 01 Nov '76Published in: Carlsberg research communications


Ribulose 1,5-diphosphate carboxylase has been purified from fully expanded leaves ofOenothera. The isolation procedure overcame the problems which resulted from a high content of mucilage and phenolic compounds in the leaves. Protein extraction into dilute buffer containing a phenol adsorbant and reducing agents followed by a combination of gel filtration and ion exchange chromatography allowed the enzyme to be essentially purified to homogeneity. The purified RuDP carboxylase had a specific activity of 1.5 μmoles CO2 fixed. min−1. mg−1 at pH 7.8 and 25°. The two subunits could be dissociated in detergent solutions and were found to have molecular weights and amino acid compositions similar to the respective subunits from other sources. A two-dimensional mapping procedure employing ion exchange and paper chromatography was used to partially characterize the tryptic peptides of the RuDP carboxylase subunits; this technique may be useful in interspecific comparisons of the primary structure of the two subunits fromOenothera species.