Abstract
Ferredoxin-reducing substance (FRS), a new electron-transfer component of the photosynthetic electron-transport chain, appears to function on the reducing side of photosystem I. It protects against the inhibition of photosystem I reactions by antibodies specifically inhibiting anthraquinone and NADP reduction. An antigenic substance prepared from ether-extracted chloroplasts, with some properties similar to those of FRS, protects only against the antibody specifically blocking anthraquinone reduction. When chloroplast fragments depleted of FRS catalyze a Mehler-type reaction, maximal rates of oxygen uptake occur only when both FRS and methyl viologen are present; either alone is insufficient. These findings support the view that FRS accepts electrons from the system I photoact and in a subsequent dark reaction transfers them to low-potential redox carriers such as ferredoxin or methyl viologen. It is one of a number of preparations from chloroplasts which catalyze reactions associated with photosynthetic electron transport. Based on their properties, it is suggested that they may have a limited common identity.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
