Surface Charge Density Changes in Isolated Photosystem II Membranes Induced by Depletion of the Extrinsic Polypeptides of the Oxygen Evolving System

1990 ◽  
Vol 45 (6) ◽  
pp. 627-632 ◽  
Author(s):  
Alexander G. Ivanov ◽  
Mira C. Busheva ◽  
Maya Y. Velitchkova
Keyword(s):  
Charge Density ◽  
Surface Charge ◽  
Surface Charge Density ◽  
Oxygen Evolving Complex ◽  
Partial Recovery ◽  
Ps Ii ◽  
Extrinsic Polypeptides ◽  
Evolving System ◽  
Oxygen Evolving System ◽  
Oxygen Evolving

Abstract Treatment of PS II particles with either 1 M NaCl or alkaline Tris (1 M , pH 8.4) caused a considerable decrease in the average net negative surface charge density, concomitant with depletion of the extrinsic 17, 24 and 33 kDa proteins of the oxygen evolving complex from the membranes. The partial recovery of the values for surface charge in both NaCl- and Tris-treated membranes was registered after reconstitution experiments with the three proteins. These results are compared with the data for the charge densities of the thylakoid membranes, to examine the role of the three extrinsic proteins in the formation of heterogeneous arrangement of surface charge across the appressed (granal) thylakoids.

Studies on the Effect of Diphenylcarbazide in Isolated Chloroplasts from Spinach

1974 ◽  
Vol 29 (11-12) ◽  
pp. 705-709 ◽  
Author(s):  
Götz Harnischfeger
Keyword(s):  
Electron Transport ◽  
Transport Parameters ◽  
Ps Ii ◽  
Transport Efficiency ◽  
Pigment System ◽  
Ps I ◽  
Evolving System ◽  
Oxygen Evolving System ◽  
Oxygen Evolving ◽  
Isolated Chloroplasts

Abstract The influence of diphenylcarbohydrazide (DPC) on electron transport parameters of chloroplasts was studied through the use of hypotonically disintegrated plastids in various states of membrane disarray. The observation that DPC acts as donator for PS II when the natural source becomes inefficient was confirmed. Contrary to prior contentions oxygen evolution is not diminished upon addition of DPC. A definite though transient influence of DPC on the pigment system was detected. At a certain state of structural disarray DPC increases the quantum yield and electron transport efficiency through PS II, while simultaneously decreasing the activity of PS I. The effect is not based on addition or removal of individual pigments to the pigment complexes. The analysis of light inten­sity curves and fluorescence kinetics suggest a better migration of trapped light to open reaction centers. The results are discussed for possible implications on the analysis of the oxygen evolving system as well as on spillover mechanisms.

scholarly journals Mapping Surface Charge Distribution of Single-Cell via Charged Nanoparticle

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1519
Author(s):  
Leixin Ouyang ◽  
Rubia Shaik ◽  
Ruiting Xu ◽  
Ge Zhang ◽  
Jiang Zhe
Keyword(s):  
Cell Surface ◽  
Charge Density ◽  
Surface Charge ◽  
Charge Distribution ◽  
Surface Charge Density ◽  
Single Cells ◽  
Fluorescent Light ◽  
Fluorescent Nanoparticles ◽  
Cell Surface Charge ◽  
Surface Charge Distribution

Many bio-functions of cells can be regulated by their surface charge characteristics. Mapping surface charge density in a single cell’s surface is vital to advance the understanding of cell behaviors. This article demonstrates a method of cell surface charge mapping via electrostatic cell–nanoparticle (NP) interactions. Fluorescent nanoparticles (NPs) were used as the marker to investigate single cells’ surface charge distribution. The nanoparticles with opposite charges were electrostatically bonded to the cell surface; a stack of fluorescence distribution on a cell’s surface at a series of vertical distances was imaged and analyzed. By establishing a relationship between fluorescent light intensity and number of nanoparticles, cells’ surface charge distribution was quantified from the fluorescence distribution. Two types of cells, human umbilical vein endothelial cells (HUVECs) and HeLa cells, were tested. From the measured surface charge density of a group of single cells, the average zeta potentials of the two types of cells were obtained, which are in good agreement with the standard electrophoretic light scattering measurement. This method can be used for rapid surface charge mapping of single particles or cells, and can advance cell-surface-charge characterization applications in many biomedical fields.

Triboelectrification of nanocomposites using identical polymer matrixes with different concentrations of nanoparticle fillers

2021 ◽  
Author(s):  
Linards Lapčinskis ◽  
Artis Linarts ◽  
Kaspars Mālnieks ◽  
Hyunseung Kim ◽  
Kristaps Rubenis ◽  
...  
Keyword(s):  
Charge Density ◽  
Surface Charge ◽  
Surface Charge Density ◽  
Polymer Layers

In this study, we investigate triboelectrification in polymer-based nanocomposites using identical polymer matrixes containing different concentrations of nanoparticles (NPs). The triboelectric surface charge density on polymer layers increased as the...

scholarly journals Effect of Selected Anionic and Cationic Drugs Affecting the Central Nervous System on Electrical Properties of Phosphatidylcholine Liposomes: Experiment and Theory

2021 ◽  
Vol 22 (5) ◽  
pp. 2270
Author(s):  
Joanna Kotyńska ◽  
Monika Naumowicz
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Charge Density ◽  
Surface Charge ◽  
Surface Charge Density ◽  
Barbituric Acid ◽  
Membrane Surface ◽  
Adsorption Equilibria ◽  
Two Component ◽  
The Central Nervous System

Interactions between phospholipid membranes and selected drugs affecting the central nervous system (CNS) were investigated. Small, unilamellar liposomes were used as biomimetic cell membrane models. Microelectrophoretic experiments on two-component liposomes were performed using the electrophoretic light scattering technique (ELS). The effect of both positively (perphenazine, PF) and negatively (barbituric acid, BA) charged drugs on zwitterionic L-α-phosphatidylcholine (PC) membranes were analyzed. Experimental membrane surface charge density (d) data were determined as a function of pH. Quantitative descriptions of the adsorption equilibria formed due to the binding of solution ions to analyzed two-component membranes are presented. Binding constants of the solution ions with perphenazine and barbituric acid-modified membranes were determined. The results of our research show that both charged drugs change surface charge density values of phosphatidylcholine membranes. It can be concluded that perphenazine and barbituric acid are located near the membrane surface, interacting electrostatically with phosphatidylcholine polar heads.

Surface charging parameters of charged particles in symmetrical electrolyte solutions

2020 ◽  
Vol 22 (35) ◽  
pp. 20123-20142
Author(s):  
Hadi Saboorian-Jooybari ◽  
Zhangxin Chen
Keyword(s):  
Charge Density ◽  
Surface Charge ◽  
Electrolyte Solution ◽  
Surface Charge Density ◽  
Potential Surface ◽  
Research Work ◽  
Charged Particles ◽  
Electrolyte Solutions ◽  
Surface Charging ◽  
Curvature Dependence

This research work is directed at development of accurate physics-based formulas for quantification of curvature-dependence of surface potential, surface charge density, and total surface charge for cylindrical and spherical charged particles immersed in a symmetrical electrolyte solution.

A multi-dielectric-layered triboelectric nanogenerator as energized by corona discharge

Nanoscale ◽  
2017 ◽  
Vol 9 (27) ◽  
pp. 9668-9675 ◽  
Author(s):  
Jia Jia Shao ◽  
Wei Tang ◽  
Tao Jiang ◽  
Xiang Yu Chen ◽  
Liang Xu ◽  
...  
Keyword(s):  
Charge Density ◽  
Surface Charge ◽  
Corona Discharge ◽  
Surface Charge Density ◽  
High Surface ◽  
Cycling Stability ◽  
Triboelectric Nanogenerator ◽  
Excellent Cycling Stability ◽  
Vertical Contact ◽  
High Surface Charge Density

A multi-dielectric-layered vertical contact-separation mode TENG through a corona discharge approach results in outstanding output performances, i.e., a high surface charge density of 283 μC m−2 and excellent cycling stability (92.6% retention after 200 000 cycles).

Modelling soil surface charge density using mineral composition

Geoderma ◽  
2004 ◽  
Vol 121 (1-2) ◽  
pp. 123-133 ◽  
Author(s):  
C. Taubaso ◽  
M. Dos Santos Afonso ◽  
R.M. Torres Sánchez
Keyword(s):  
Charge Density ◽  
Surface Charge ◽  
Mineral Composition ◽  
Surface Charge Density ◽  
Soil Surface
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