Plasmalogens in Biological Systems: Their Role in Oxidative Processes in Biological Membranes, their Contribution to Pathological Processes and Aging and Plasmalogen Analysis

2009 ◽  
Vol 16 (16) ◽  
pp. 2021-2041 ◽  
Author(s):  
J. Leßig ◽  
B. Fuchs
Keyword(s):  
Biological Systems ◽  
Biological Membranes ◽  
Oxidative Processes

scholarly journals Estimating the effectiveness of protection against UV radiation with extracts of lichen Hypogymnia physodes in biological systems in vivo

2020 ◽  
Vol 63 (6) ◽  
pp. 747-754
Author(s):  
S. V. Goncharov ◽  
A. E. Kozlov ◽  
M. V. Маtveyenkov ◽  
I. A. Cheshik
Keyword(s):  
Biochemical Parameters ◽  
Biological Systems ◽  
Control Level ◽  
High Sensitivity ◽  
Morphometric Parameters ◽  
Hypogymnia Physodes ◽  
Sh Groups ◽  
Oxidative Processes ◽  
Acetone Extracts

The reactivity of biological systems to UV-A/B and the photoprotective potential of skin applications of lichen extracts Hypogymnia physodes according to the biochemical parameters of blood and morphometric parameters of the skin were evaluated in vivo in laboratory mice. Ethanol, acetone and hexane–acetone extracts (1 % in dimethylsulfoxide) effectively absorb the UV range inducing the most erythema. On the 4th day after UV-A/Вirradiation, severe brown burns of the back skin, severe erythema and edema, scab formation were observed. In serum, there were significantly changed biochemical parameters – the prooxidant capacity, the level of nitrate/nitrite-ions NOx, advanced oxidation protein products AOPP, glutathioneperoxidase activity GPx increased, the level of SH-groups reduced. Solutions of extracts (5 %) in dimethylsulfoxide at a different degree exhibited the photoprotective effect: morphologically – in minimizing the burn symptoms of the skin (edema, erythema, scab); biochemically – in the regulation of these parameters at the control level. According to the set of biochemical and morphometric parameters, the most promising photoprotectors were acetone extracts. The prooxidant capacity, GPx, AOРР (in all cases reduced) and NOx showed a non-specificity and rather high sensitivity and are more suitable for estimating inflammatory and oxidative processes. The highest efficiency and the adequacy to the tasks and the specifications are shown by the level of protein SH-groups.

scholarly journals Barriers to the free diffusion of proteins and lipids in the plasma membrane

2015 ◽  
Vol 208 (3) ◽  
pp. 259-271 ◽  
Author(s):  
William S. Trimble ◽  
Sergio Grinstein
Keyword(s):  
Plasma Membrane ◽  
Biological Systems ◽  
Biological Membranes ◽  
Physical Nature ◽  
Functional Domains ◽  
Free Diffusion ◽  
Entire Life ◽  
Protein Components

Biological membranes segregate into specialized functional domains of distinct composition, which can persist for the entire life of the cell. How separation of their lipid and (glyco)protein components is generated and maintained is not well understood, but the existence of diffusional barriers has been proposed. Remarkably, the physical nature of such barriers and the manner whereby they impede the free diffusion of molecules in the plane of the membrane has rarely been studied in depth. Moreover, alternative mechanisms capable of generating membrane inhomogeneity are often disregarded. Here we describe prototypical biological systems where membrane segregation has been amply documented and discuss the role of diffusional barriers and other processes in the generation and maintenance of their structural and functional compartmentalization.

scholarly journals Organosilicon uptake by biological membranes

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Pepijn Beekman ◽  
Agustin Enciso-Martinez ◽  
Sidharam P. Pujari ◽  
Leon W. M. M. Terstappen ◽  
Han T. Zuilhof ◽  
...  
Keyword(s):  
Cell Membrane ◽  
Cell Membranes ◽  
Biological Systems ◽  
Biological Membranes ◽  
Analytical Techniques ◽  
Potential Effect ◽  
Organosilicon Compounds

AbstractOrganosilicon compounds are ubiquitous in everyday use. Application of some of these compounds in food, cosmetics and pharmaceuticals is widespread on the assumption that these materials are not systemically absorbed. Here the interactions of various organosilicon compounds (simeticone, hexamethyldisilazane and polydimethylsiloxane) with cell membranes and models thereof were characterized with a range of analytical techniques, demonstrating that these compounds were retained in or on the cell membrane. The increasing application of organosilicon compounds as replacement of other plastics calls for a better awareness and understanding of these interactions. Moreover, with many developments in biotechnology relying on organosilicon materials, it becomes important to scrutinize the potential effect that silicone leaching may have on biological systems.

Electron Diffraction of Wet Biological Membranes

1974 ◽  
Vol 32 ◽  
pp. 158-159
Author(s):  
S.W. Hui ◽  
D.F. Parsons
Keyword(s):  
Electron Diffraction ◽  
Data Collection ◽  
Biological Membranes ◽  
Small Areas ◽  
Electron Diffraction Technique ◽  
Electron Microscopes ◽  
Collection Time ◽  
Camera Length

The development of the hydration stages for electron microscopes has opened up the application of electron diffraction in the study of biological membranes. Membrane specimen can now be observed without the artifacts introduced during drying, fixation and staining. The advantages of the electron diffraction technique, such as the abilities to observe small areas and thin specimens, to image and to screen impurities, to vary the camera length, and to reduce data collection time are fully utilized. Here we report our pioneering work in this area.

Transmission Electron Microscopy of Protein Macromolecules

1971 ◽  
Vol 29 ◽  
pp. 424-425
Author(s):  
Henry S. Slayter
Keyword(s):  
Biological Systems ◽  
Metal Vapor ◽  
Resolving Power ◽  
Electron Microscopic ◽  
Chemical Methods ◽  
Molecular Weights ◽  
The Past ◽  
Physical Chemical ◽  
Transmission Electron

Electron microscopic methods have been applied increasingly during the past fifteen years, to problems in structural molecular biology. Used in conjunction with physical chemical methods and/or Fourier methods of analysis, they constitute powerful tools for determining sizes, shapes and modes of aggregation of biopolymers with molecular weights greater than 50, 000. However, the application of the e.m. to the determination of very fine structure approaching the limit of instrumental resolving power in biological systems has not been productive, due to various difficulties such as the destructive effects of dehydration, damage to the specimen by the electron beam, and lack of adequate and specific contrast. One of the most satisfactory methods for contrasting individual macromolecules involves the deposition of heavy metal vapor upon the specimen. We have investigated this process, and present here what we believe to be the more important considerations for optimizing it. Results of the application of these methods to several biological systems including muscle proteins, fibrinogen, ribosomes and chromatin will be discussed.

Observation of Concanavalin-A receptors on hydrated planar erythrocyte membrane film by in situ electron microscopy

1983 ◽  
Vol 41 ◽  
pp. 608-609
Author(s):  
Neng-Bo He ◽  
S.W. Hui
Keyword(s):  
Lipid Bilayers ◽  
Erythrocyte Membrane ◽  
Lipid Membranes ◽  
Surface Film ◽  
Biological Membranes ◽  
Electron Microscopic Observation ◽  
Electron Microscopic ◽  
Black Lipid Membranes ◽  
Fine Mesh ◽  
Planar Films

Monolayers and planar "black" lipid membranes have been widely used as models for studying the structure and properties of biological membranes. Because of the lack of a suitable method to prepare these membranes for electron microscopic observation, their ultrastructure is so far not well understood. A method of forming molecular bilayers over the holes of fine mesh grids was developed by Hui et al. to study hydrated and unsupported lipid bilayers by electron diffraction, and to image phase separated domains by diffraction contrast. We now adapted the method of Pattus et al. of spreading biological membranes vesicles on the air-water interfaces to reconstitute biological membranes into unsupported planar films for electron microscopic study. hemoglobin-free human erythrocyte membrane stroma was prepared by hemolysis. The membranes were spreaded at 20°C on balanced salt solution in a Langmuir trough until a surface pressure of 20 dyne/cm was reached. The surface film was repeatedly washed by passing to adjacent troughs over shallow partitions (fig. 1).

Freeze-fracture cytochemistry: A goal set by Russell Steere in 1957

1993 ◽  
Vol 51 ◽  
pp. 60-61
Author(s):  
Nicholas J Severs
Keyword(s):  
Chemical Nature ◽  
Biological Systems ◽  
Freeze Fracture ◽  
Structural Components ◽  
Major Goal ◽  
Membrane Biology ◽  
Routine Application ◽  
The Future ◽  
Freeze Etching

In his pioneering demonstration of the potential of freeze-etching in biological systems, Russell Steere assessed the future promise and limitations of the technique with remarkable foresight. Item 2 in his list of inherent difficulties as they then stood stated “The chemical nature of the objects seen in the replica cannot be determined”. This defined a major goal for practitioners of freeze-fracture which, for more than a decade, seemed unattainable. It was not until the introduction of the label-fracture-etch technique in the early 1970s that the mould was broken, and not until the following decade that the full scope of modern freeze-fracture cytochemistry took shape. The culmination of these developments in the 1990s now equips the researcher with a set of effective techniques for routine application in cell and membrane biology.Freeze-fracture cytochemical techniques are all designed to provide information on the chemical nature of structural components revealed by freeze-fracture, but differ in how this is achieved, in precisely what type of information is obtained, and in which types of specimen can be studied.

Seeking to uncover biology's chemical roots

2019 ◽  
Vol 3 (5) ◽  
pp. 435-443 ◽  
Author(s):  
Addy Pross
Keyword(s):  
Environmental Changes ◽  
Biological Systems ◽  
Significant Development ◽  
The Road ◽  
Physical Chemical ◽  
Systems Chemistry ◽  
Biological World ◽  
Inanimate Matter ◽  
The Origin Of Life ◽  
Opening Up

Despite the considerable advances in molecular biology over the past several decades, the nature of the physical–chemical process by which inanimate matter become transformed into simplest life remains elusive. In this review, we describe recent advances in a relatively new area of chemistry, systems chemistry, which attempts to uncover the physical–chemical principles underlying that remarkable transformation. A significant development has been the discovery that within the space of chemical potentiality there exists a largely unexplored kinetic domain which could be termed dynamic kinetic chemistry. Our analysis suggests that all biological systems and associated sub-systems belong to this distinct domain, thereby facilitating the placement of biological systems within a coherent physical/chemical framework. That discovery offers new insights into the origin of life process, as well as opening the door toward the preparation of active materials able to self-heal, adapt to environmental changes, even communicate, mimicking what transpires routinely in the biological world. The road to simplest proto-life appears to be opening up.

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