title: Energy and Electron Transfer Systems of Chlamydomonas reinhardi. I. Photosynthetic and Respiratory Cytochrome Systems of the Pale Green Mutant.
abstract: The role of cytochromes in photosynthetic electron transfer system has been studied using the pale green mutant of Chlamydomonas reinhardi (ATCC 18302). The existence of cytochromes b(563) and f is confirmed, while no significant amount of ascorbate-reducible cytochrome b(559) is detected in this mutant. The presence of cytochrome c and a small amount of a-type cytochrome is determined in these cells.Light-induced oxidation of cytochrome b(563) is eliminated by oxygen-induced oxidation, and oxygen-induced oxidation is greatly diminished under illumination. Antimycin A diminishes the oxygen-induced oxidation of cytochrome b(563), but does not affect light-induced oxidation. In the aerobic state in the presence of 2-heptyl-4-hydroxyquinoline-N-oxide, cytochrome b(563) is reduced by illumination with far red light; this reduction is not inhibited by 3-(4'-chlorophenyl)-1,1-dimethylurea.A tentative scheme for the electron transfer system in chloroplasts, which involves a cyclic pathway via cytochrome b(563) and its interaction with oxygen, is proposed.
authors.affiliation: Johnson Research Foundation, University of Pennsylvania, Philadelphia, Pennsylvania 19104.
authors.forename: T
authors.initials: T
authors.lastname: Hiyama
authors.forename: M
authors.initials: M
authors.lastname: Nishimura
authors.forename: B
authors.initials: B
authors.lastname: Chance