Abstract
Cytochrome c reducing substance (CRS), a redox substance discovered in photoreactive lamellar fragments, was purified by Sephadex column chromatography. Chromatographic behaviours of CRS of Anabaena and spinach were essentially the same. Purified CRS of Anabaena showed an absorption spectrum having one absorption maximum around 260 mμ. The absorption peak disappeared on addition of excess amount of borohydride. Similar absorption change on borohydride addition was observed with spinach CRS preparation. Purified preparations of Anabaena and spinach CRS supported photophosphorylation in spinach broken chloroplasts. The phosphorylation was found to couple the electron flow from water to molecular oxygen.