On the location of the tetrapyrrole macrocycle of chlorophyll a in phospholipid vesicles and in hexadecane

Summary The state of chlorophyll a in phosphatidylcholine vesicles was examined. The results indicate that the chlorophylls are present in monomeric form. A kinetic study of chlorophyll reactions with K₂S₂O₈ and piperidine showed that these substances react with the porphyrin rings of pigments located on both vesicle faces, most probably within the polar headgroup region.Acknowledgments. This work was supported by the Research Committee and the Biophysics Research Group, University of Québec at Trois-Rivières.