EurekaMag.com logo
+ Translate

Spectral and kinetic evidence for 2 early electron acceptors in photosystem i


, : Spectral and kinetic evidence for 2 early electron acceptors in photosystem i. Proceedings of the National Academy of Sciences of the United States of America 76(2): 770-773

Triton-fractionated photosystem-I particles poised at -625 mV, where the 2 bound Fe-S proteins are reduced, were studied by optical and EPR spectroscopies from 293-5.degree. K. At 5-9.degree. K, these particles exhibit 2 decay components with lifetimes of 1.3 and 130 ms in the laser pulse-induced absorption and EPR signal changes. Spectral properties of the 130 ms decay component reflect the charge separation between P-700 and some Fe-S center having a broad optical absorbance in the 400-550 nm region and a previously reported EPR signal with g = 1.78, 1.88 and 2.08. Spectral properties of the 1-msec decay component indicate photoinduced charge separation between P-700 and a chlorophyll a dimer having absorption bands at 420, 450 and 700 nm. It is assumed that these 2 acceptors participate in the electron transfer from P-700* to the bound Fe-S proteins.

(PDF 0-2 workdays service)

Accession: 006459502

Submit PDF Full Text: Here


Submit PDF Full Text

No spam - Every submission is manually reviewed

Due to poor quality, we do not accept files from Researchgate

Submitted PDF Full Texts will always be free for everyone
(We only charge for PDFs that we need to acquire)

Select a PDF file:
Close
Close

Related references

Shuvalov, V.A.; Dolan, E.; Ke, B., 1979: Spectral and kinetic evidence for two early electron acceptors in photosystem I. Triton-fractionated photosystem-I particles poised at -625 mV, where the two bound iron-sulfur proteins are reduced, have been studied by optical and electron paramagnetic resonance spectroscopies from 293 to 5 K. At 5-9 K, these particles exhibit...

Wolfgang Nitschke; Ute Feiler; Wolfgang Lockau; Günter Hauska, 1987: The photosystem of the green sulfur bacterium chlorobium limicola contains two early electron acceptors similar to photosystem i. An asymmetric EPR-line with a g factor of 2.0045 was detected after phototrapping at 196 K in membranes and in isolated photoactive P840 reaction centers of Chlorobium limicola f. thiosulfatophilum. The spectra resemble those of the electron accep...

Evans M.C.W.; Atkinson Y.E.; Ford R.C., 1985: Redox characterization of the photosystem ii electron acceptors evidence for 2 electron carriers between pheophytin and q. The oxidation reduction potential dependence of low-temperature photochemical reactions associated with the electron acceptors of photosystem II has been determined in photosystem II preparations from spinach and Chlamydomonas reinhardtii. The red...

Evans, M.; Atkinson, Y.; Ford, R., 1985: Redox characterisation of the Photosystem II electron acceptors. Evidence for two electron carries between pheophytin and Q. Biochimica et biophysica acta: bioenergetics, 806(2): 247-254

Guikema, J.A.; Yocum, C.F., 1979: Steady-state kinetic analyses of photosystem II activity catalyzed by lipophilic electron acceptors. Biochimica et Biophysica Acta 547(2): 241-251

Guikema, J.; Yocum, C., 1979: Steady-state kinetic analyses fo Photosystem II activity catalyzed by lipophilic electron acceptors. Biochimica et biophysica acta, 547(2): 241-251

Smith, N.; Mansfield, R.; Nugent, J.; Evans, M., 1986: Evidence for the existence of electron acceptors A0 and A1 in cyanobacterial photosystem 1. Progress in photosynthesis research: proceedings of the VIIth International Congress on Photosynthesis Providence Rhode Island USA August 10-15-1986 edited by J Biggins: 247

Satoh, K.; Oh-Hashi, M.; Kashino, Y.; Koike, H., 1995: Mechanism of electron flow through the Q-B site in photosystem II. 1. Kinetics of the reduction of electron acceptors at the Q-B and plastoquinone sites in photosystem II particles from the cyanobacterium Synechococcus vulcanus. Various derivatives of benzoquinone (BQ) were found to be reduced at two sites (the Q-B and plastoquinone (PQ) sites) in photosystem II particles from Synechococcus vulcanus, and the relationship between the structures of BQs and the kinetics of s...

Setif, P., Q.Y.; Bottin, H., 1995: Laser flash absorption spectroscopy study of ferredoxin reduction by photosystem I: Spectral and kinetic evidence for the existence of several photosystem I-ferredoxin complexes. The existence of three first-order phases has been previously reported for the reduction of soluble ferredoxin by photosystem I (PSI), both from the cyanobacterium Synechocystis sp. PCC 6803 (at pH 8 and in the presence of salts) (Setif, P. Q. Y.,...

Sétif, P.Q.; Bottin, H., 1995: Laser flash absorption spectroscopy study of ferredoxin reduction by photosystem I: spectral and kinetic evidence for the existence of several photosystem I-ferredoxin complexes. The existence of three first-order phases has been previously reported for the reduction of soluble ferredoxin by photosystem I (PSI), both from the cyanobacterium Synechocystis sp. PCC 6803 (at pH 8 and in the presence of salts) [Sétif, P. Q. Y....