Superoxide Dismutase Archives

Schematic representation of oxygenic photosynthesis and the generation of superoxide during the day inside a Cyanobacterial cell. The thylakoid membrane contains Photosystem II (PSII) connected to phycobilisomes, Photosystem I (PSI), cytochrome b6f (cyt b6f), and electron transporters plastoquinone (PQ) and plastocyanin (PC). Phycobilisomes capture light energy and transfer it to PSII resulting in the hydrolysis of water and transfer of electrons to PQ, with the concomitant generation of molecular oxygen (O2) and protons (H+ ). PQ then transfers the electrons to PSI via cyt b6f and PC, thereby translocating two protons (2H+ ) across the thylakoid membrane, into the lumen. The resulting proton gradient powers the synthesis of adenosine triphosphate (ATP) via ATP synthase. PSI transfers electrons to ferredoxin (Fd), that in turn transfers electrons to ferredoxin NADP+ oxidoreductase (FNR) to generate reduced nicotinamide adenine dinucleotide phosphate (NADPH). Both NADPH and ATP are used to power cellular processes, such as CO2 fixation (Mullineaux, 2014). Increased light exposure may result in excess electrons being fed into the electron transport chain, resulting in the generation of superoxide (O2 •– ) (Latifi et al., 2009). Dismutation of O2 •– to hydrogen peroxide (H2O2) potentially occurs in different species via superoxide dimutases (SODs), in the cytoplasm, thylakoid lumen or periplasmic space (Herbert et al., 1992; Li et al., 2002; Napoli et al., 2021; Raghavan et al., 2013; Raghavan et al., 2015). Image generated in Biorender ©. -- biorxiv.org

Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biophysics, Genomics, Proteomics, Bioinformatics, Microbiology & Virology, Origin & Evolution of Life, Status Report

Early-branching Cyanobacteria Up-regulate Superoxide Dismutase Activity Under A Simulated Early Earth Anoxic Atmosphere

by Keith CowingMarch 17, 2024

The evolution of oxygenic photosynthesis during the Archean (4-2.5 Ga), required the presence of complementary reducing pathways to maintain the cellular redox balance.

Superoxide Dismutase

Early-branching Cyanobacteria Up-regulate Superoxide Dismutase Activity Under A Simulated Early Earth Anoxic Atmosphere

Preparing ExoMars For Rosalind Franklin Astrobiology Rover Delivery

Joint Dynamical-geophysical Evidence For A Limit Cycle In The Galilean Moons

JWST Transmission Spectroscopy Of TOI-3235 b: Challenges In Constraining Giant Planet Atmospheres Around M Dwarfs Amid Stellar Contamination

Searching For Habitable Exoplanets With Relative Astrometry (SHERA). I. The Case For Searching For Planets In Binary Star Systems

Callisto From JWST: CO2-rich Terrain On The Leading Hemisphere And Global Patterns Of H2O Ice