Oxygenic Photoreactivity in Photosystem II Studied by Rotating Ring Disk Electrochemistry.

ABSTRACT: Protein film photoelectrochemistry has previously been used to monitor the activity of photosystem II, the water-plastoquinone photooxidoreductase, but the mechanistic information attainable from a three-electrode setup has remained limited. Here we introduce the four-electrode rotating ring disk electrode technique for quantifying light-driven reaction kinetics and mechanistic pathways in real time at the enzyme-electrode interface. This setup allows us to study photochemical H₂O oxidation in photosystem II and to gain an in-depth understanding of pathways that generate reactive oxygen species. The results show that photosystem II reacts with O₂ through two main pathways that both involve a superoxide intermediate to produce H₂O₂. The first path

SUBMITTER: Kornienko N 

PROVIDER: S-EPMC6311681 | biostudies-literature | 2018 Dec

REPOSITORIES: biostudies-literature