IMMUNOCHEMICAL ANALYSIS OF CHLOROPLAST POLYPEPTIDES FROM MARITIME PINE

Chloroplast polypeptides have been purified to electrophoretic homogeneity from maritime pine cotyledons (Pinus pinaster aiton). Antibodies against the light harvesting chlorophyll a-b binding protein (LHCP) located in the thylakoid membrane and the stromatic ribulose bisphosphate carboxylase/oxygenase (Rubisco holoenzyme) were raised in rabbits by injecting pure preparations. Monospecificity of antibodies was determined by a double immunodiffusion test and further purification was achieved by immunoselection of IgGs with purified proteins immobilized on nitrocellulose membranes. Antisera were used to determine steady-state levels of polypeptides during plant development by slot-blot quantitation. Our data showed that developing Pinus pinaster seedlings accumulated chloroplast proteins in the dark, but no such accumulation was observed in dark-grown Ginkgo biloba seedlings.