Speed of superoxide in thylakoid membrane

Value 20 nm/sec
Organism Spinach Spinacia oleracea
Reference Ivanov BN. Cooperation of photosystem I with the plastoquinone pool in oxygen reduction in higher plant chloroplasts. Biochemistry (Mosc). 2008 Jan73(1):112-8PubMed ID18294139
Primary Source Takahashi M, Asada K. Superoxide production in aprotic interior of chloroplast thylakoids. Arch Biochem Biophys. 1988 Dec267(2):714-22.PubMed ID2850770
Comments During the lifetime of superoxide (~15 sec half life, see bion 103376) it is capable of diffusing inside the membrane for a long distance from the place of its generation, and the negative surface charges at the membrane boundaries impede its escape from the membrane. Since, under continuous illumination, the PQ pool is reduced along the whole membrane, the probability of reaction of the superoxide generated in PSI with PQH2 molecules is very high.
Entered by Uri M
ID 103377