Cytochrome b559 contained within the isolated reaction centre of photosystem II can, under anaerobic conditions, be directly reduced by photoinduced electron transfer from exogenously added flavins. This chlorophyll-independent reaction occurs when glucose oxidase is present. Glucose oxidase is a flavin-containing enzyme (its prosthetic group being flavin-adenine dinucleotide) and is often used as part of an oxygen trap together with glucose and catalase. Thus, studies using this chemical trap to create anaerobic conditions should take into account the possibility of inducing a non-photosynthetic electron transfer process in isolated photosystem II complexes. However, the flavin-catalyzed process is restricted to excitation with blue light and can be used as a convenient non-chemical method to modify the redox state of cytochrome b559.
- Cytochrome b559
- Gel electrophoresis
- Photosystem II
ASJC Scopus subject areas
- Physical and Theoretical Chemistry