Inhibition of PS II activity by copper and its effect on spectral properties on intact cells in Anacystis nidulans

1995 ◽  
Vol 35 (4) ◽  
pp. 435-439 ◽  
Author(s):  
A Gupta
Keyword(s):  
Spectral Properties ◽  
Anacystis Nidulans ◽  
Intact Cells ◽  
Ps Ii ◽  
Ps Ii Activity

Isolierung von PS II-Partikeln mit in vivo Eigenschaften aus Euglena gracilis, Stamm Z / Isolation of PS II-Particels with in vivo Characteristics from Euglena gracilis, Stamm Z

1982 ◽  
Vol 37 (3-4) ◽  
pp. 256-259 ◽  
Author(s):  
F. Schuler ◽  
P. Brandt ◽  
W. Wießner
Keyword(s):  
Euglena Gracilis ◽  
Fluorescence Emission ◽  
Improved Method ◽  
Ps Ii ◽  
Ps I ◽  
Emission And Absorption Spectra ◽  
Chlorophyll Protein ◽  
Ps Ii Activity ◽  
Photosystem Ii Particles

Abstract An improved method for isolation of (photosystem II)-particles from Euglena gracilis, strain Z was established. PS II-particles isolated by ultrasonic treatment and following differential centrifugation show fluorescence emission and absorption spectra identical with in vivo properties of Euglena gracilis. These PS II-particles have only PS II-activity and contain CP a, the typical chlorophyll-protein-complex of PS II. No contamination of PS I-components are detectable.

scholarly journals Reversible particle movements associated with unstacking and restacking of chloroplast membranes in vitro.

1976 ◽  
Vol 71 (1) ◽  
pp. 136-158 ◽  
Author(s):  
L A Staehelin
Keyword(s):  
Plasma Membranes ◽  
Structural Changes ◽  
Freeze Fracture ◽  
Chloroplast Membranes ◽  
Ps Ii ◽  
Membrane Particles ◽  
Intramembranous Particles ◽  
Membrane Surfaces ◽  
Ps Ii Activity

Freeze-fracture and freeze-etch techniques have been employed to study the supramolecular structure of isolated spinach chloroplast membranes and to monitor structural changes associated with in vitro unstacking and restacking of these membranes. High-resolution particle size histograms prepared from the four fracture faces of normal chloroplast membranes reveal the presence of four distinct categories of intramembranous particles that are nonrandomly distributed between grana and stroma membranes. The large surface particles show a one to one relationship with the EF-face particles. Since the distribution of these particles between grana and stroma membranes coincides with the distribution of photosystem II (PS II) activity, it is argued that they could be structural equivalents of PS II complexes. An interpretative model depicting the structural relationship between all categories of particles is presented. Experimental unstacking of chloroplast membranes in low-salt medium for at least 45 min leads to a reorganization of the lamellae and to a concomitant intermixing of the different categories of membrane particles by means of translational movements in the plane of the membrane. In vitro restacking of such experimentally unstacked chloroplast membranes can be achieved by adding 2-20 mM MgCl2 or 100-200 mM NaCl to the membrane suspension. Membranes allowed to restack for at least 1 h at room temperature demonstrate a resegregation of the EF-face particles into the newly formed stacked membrane regions to yield a pattern and a size distribution nearly indistinguishable from the normally stacked controls. Restacking occurs in two steps: a rapid adhesion of adjoining stromal membrane surfaces with little particle movement, and a slower diffusion of additional large intramembranous particles into the stacked regions where they become trapped. Chlorophyll a:chlorophyll b ratios of membrane fraction obtained from normal, unstacked, and restacked membranes show that the particle movements are paralleled by movements of pigment molecules. The directed and reversible movements of membrane particles in isolated chloroplasts are compared with those reported for particles of plasma membranes.

Energy transduction by the cytoplasmic membrane of intact cells of the cyanobacterium Anacystis nidulans

1983 ◽  
Vol 70 (12) ◽  
pp. 615-616 ◽  
Author(s):  
R. Muchl ◽  
G. Schmetterer ◽  
W. H. Nitschmann ◽  
G. A. Peschek
Keyword(s):  
Cytoplasmic Membrane ◽  
Anacystis Nidulans ◽  
Energy Transduction ◽  
Intact Cells

Photosynthetische Reaktionen in lyophilisierten Zellen der Blaualge Anacystis

1965 ◽  
Vol 20 (9) ◽  
pp. 879-885 ◽  
Author(s):  
Bernt Gerhardt ◽  
Achim Trebst
Keyword(s):  
Simple Procedure ◽  
Anacystis Nidulans ◽  
Intact Cells ◽  
Atp Formation ◽  
Cyclic Photophosphorylation ◽  
Photosynthetic Activities ◽  
Bluegreen Algae ◽  
Isolated Chloroplasts

Intact cells of the bluegreen algae Anacystis nidulans photoreduce p-benzoquinone under O2-evolution but not ferricyanide. Catalytic amounts of a quinone catalyze the photoreduction of ferricyanide; the more positive its redoxpotential the better is the stimulation.By the simple procedure of lyophilizing Anacystis in 5% sucrose and resuspending in 4·10—2-m. magnesiumchloride a preparation is obtained which exhibits the same photosynthetic activities as known from isolated chloroplast fragments, i. e. they evolve oxygen and photoreduce ferricyanide, quinones and NADP *; these Hill- reactions are coupled to ATP-formation; they catalyze pseudocyclic and cyclic photophosphorylation. Rates compare favorably with those of isolated chloroplasts except for the NADP-system.A number of known inhibitors like DCMU, KCN, dinitrophenol, salicylaldoxime and ammoniumchloride were checked and found to behave in principal as in photosynthetic chloroplast reactions.

Interaction of pretilachlor with PS-II activity of the cyanobacterium Desmonostoc muscorum PUPCCC 405.10

2020 ◽  
Vol 60 (6) ◽  
pp. 532-542
Author(s):  
Gurdeep Kaur Swatch ◽  
Davinder Pal Singh ◽  
Jasvirinder Singh Khattar ◽  
Pradipta Kumar Mohapatra
Keyword(s):  
Ps Ii ◽  
Ps Ii Activity

Effect of Irradiation and Immobilization on Spinach Chloroplast Activities

1980 ◽  
Vol 35 (5-6) ◽  
pp. 477-481 ◽  
Author(s):  
T. Fujimura ◽  
F. Yoshii ◽  
I. Kaetsu ◽  
Y. Inoue ◽  
K. Shibata
Keyword(s):  
Low Temperature ◽  
Active Center ◽  
Polymer Matrix ◽  
O2 Evolution ◽  
Hydrophilic Polymer ◽  
Spinach Chloroplast ◽  
Ps Ii ◽  
Thermo Stability ◽  
Ps Ii Activity ◽  
Isolated Chloroplasts

Abstract The effect of y-ray irradiation and immobilization by means of radiation polymerization on PS II activity (O2 evolution) of isolated chloroplasts from spinach was investigated. Reduction of O2 evolution activity by irradiation was small at lower temperatures below – 24 °C, but the activity decreased slightly by freezing at extremely low temperature below –78 °C. So the optimum low temperature range for the treatment was observed. The immobilized chloroplast in a hydrophilic polymer matrix showed the stable duration of O2 evolution activity more than 700 h at 4 °C . Thermo-stability of chloroplast was also improved greatly by immobilization. The active center of PS II in immobilized chloroplasts was retained even after 60 min standing at 50 °C.

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