Results 121 to 130 of about 2,591 (159)

Effect of chlorophyllase treatment on photooxidation of P700 in chloroplast fragments

Biochimica et Biophysica Acta (BBA) - Bioenergetics, 1972
Abstract The effects of chlorophyllase (chlorophyll chlorophyllido-hydrolase, EC 3.1.1.14) treatment on the photooxidation of P700 in chloroplast fragments (180P particles) were investigated. The magnitude of steady-state photooxidation of P700 was decreased by incubation with chlorophyllase in the presence of 25% acetone. The amount of P700 in 180P
K I, Takamiya, M, Nishimura
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Characterization of P700 by FTIR Difference Spectroscopy

1990
The primary photochemical act in photosynthesis leads to the generation of the radical cation of a specialized chlorophyll (Chl) or bacteriochlorophyll (BChl) species. For purple bacteria, the primary electron donor is a pair of BChl whose molecular structure has been extensively investigated by various spectroscopic techniques and recently elucidated ...
E. Nabedryk, M. Leonhard, W. Mäntele, J. Breton   +3 more
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Primary Donor Photo-Oxidation in Photosystem I:  A Re-Evaluation of (P700⁺ − P700) Fourier Transform Infrared Difference Spectra

Biochemistry, 2001
Light-induced Fourier transform infrared (FTIR) difference spectroscopy has been used to study the photo-oxidation of the primary electron donor (P700) in PS I particles from Chlamydomonas reinhardtii and Synechocystis sp. PCC 6803. To aid in the interpretation of the spectra, PS I particles from a site-directed mutant of C.
G, Hastings, V M, Ramesh, R, Wang, V, Sivakumar, A, Webber   +4 more
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Primary Charge Separation in Photosystem I: A Two-Step Electrogenic Charge Separation Connected with P700+A0- and P700+A1- Formation

Biochemistry, 1994
A PS I membrane preparation from a PS II deficient mutant of Synechocystis sp. PCC 6803 (psb DI/DII/C) was investigated by picosecond photovoltage and fluorescence measurements. The photovoltage kinetics show two distinct phases. At low excitation energies the fast phase correlates with the fluorescence decay time constant of 22 +/- 4 ps. This phase is
B, Hecks, K, Wulf, J, Breton, W, Leibl, H W, Trissl   +4 more
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On the Electron Transfer from Plastocyanin to P700

1987
In the photosynthetic electron transfer chain the oxidized reaction center P700+ of photosystem I is reduced by the electron carrier plastocyanin. The plastocyanin-oxidase site of P700+ is located on the luminal side of the thylakoid membrane, which necessitates the use of detergent treatment or mechanical disruption to allow the access of externally ...
Wolfgang Haehnel, Rafael Ratajczak, Rowan Mitchell   +2 more
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PROTONATED SCHIFFS BASE CHLOROPHYLL: A MODEL FOR P700?

Photochemistry and Photobiology, 1984
Abstract— A Schiff's base of the Ni(II) analog of pyrochlorophyll a (PChl a) has been synthesized which exhibits a reversible bathochromic shift relative to Ni‐PChl a of 504 cm‐1. The shift approaches that observed between Chi a and P700, the photoactive pigment of photosystem I in plants, and suggests that the protonated Schiff s base may be an ...
Linda L. Maggiora, Gerald M. Maggiora
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Photosystem II activity of chloroplast fragments lacking P700

Biochimica et Biophysica Acta (BBA) - Bioenergetics, 1971
Abstract Chloroplast fragments, prepared with the detergent Triton X-100, had a pigment composition characteristic of Photosystem II. The fragments had chlorophyll a/chlorophyll b ratios of 1.7–1.9 and had no detectable P700, either by photochemical or chemical assay.
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Charge recombination between P700+ and A1- occurs directly to the ground state of P700 in a photosystem I core devoid of FX, FB, and FA

Biochemistry, 1993
The charge recombination between P700+ and electron acceptor A1- was studied by flash kinetic spectroscopy in a photosystem I core devoid of iron-sulfur centers FX, FB, and FA. We showed previously that the majority of the flash-induced absorption change at 820 nm decayed with a 10-microseconds half-time, which we assigned to the disappearance of the ...
P V, Warren, J H, Golbeck, J T, Warden
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Stark effect in P700, the primary electron donor of Photosystem I [PDF]

FEBS Letters, 1991
Quadratic Stark effect in CP1 pigment‐protein complex was examined at low temperatures in the red spectral region. The Stark spectra of samples containing P700 in reduced form exhibit a strong negative band at 704 nm, which disappears on chemical oxidation of P700.
Krawczyk, S., Maksymiec, W.
exaly   +3 more sources

P700 sensitization by low concentration of DCMU in isolated pea chloroplasts

Biochemical and Biophysical Research Communications, 1981
Abstract Using steady-state relaxation spectrophotometric technique a P700 component ( t 1 2 ∼20 ms ) has been detected which was sensitized by low concentration (10−7M) DCMU in isolated broken chloroplasts of pea. The relative quantum yield of electron flux through DCMU-sensitized P700 was similar to that with methyl viologen or NADP as ...
S, Bose, G E, Hoch
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