CHARACTERISATION OF MYOGENIC CELL MEMBRANE: II. DYNAMIC CHANGES IN MEMBRANE LIPIDS DURING THE DIFFERENTIATION OF MOUSE C2 MYOBLAST CELLS

2001 ◽  
Vol 25 (10) ◽  
pp. 971-979 ◽  
Author(s):  
M Nakanishi
2012 ◽  
Vol 9 (4) ◽  
pp. 285-292 ◽  
Author(s):  
Seyed Mohammad Nabavi ◽  
Seyed Fazel Nabavi ◽  
William N. Setzer ◽  
Heshmatollah Alinezhad ◽  
Mahboobeh Zare ◽  
...  

2008 ◽  
Vol 74 (12) ◽  
pp. 3764-3773 ◽  
Author(s):  
Dina Raafat ◽  
Kristine von Bargen ◽  
Albert Haas ◽  
Hans-Georg Sahl

ABSTRACT Chitosan is a polysaccharide biopolymer that combines a unique set of versatile physicochemical and biological characteristics which allow for a wide range of applications. Although its antimicrobial activity is well documented, its mode of action has hitherto remained only vaguely defined. In this work we investigated the antimicrobial mode of action of chitosan using a combination of approaches, including in vitro assays, killing kinetics, cellular leakage measurements, membrane potential estimations, and electron microscopy, in addition to transcriptional response analysis. Chitosan, whose antimicrobial activity was influenced by several factors, exhibited a dose-dependent growth-inhibitory effect. A simultaneous permeabilization of the cell membrane to small cellular components, coupled to a significant membrane depolarization, was detected. A concomitant interference with cell wall biosynthesis was not observed. Chitosan treatment of Staphylococcus simulans 22 cells did not give rise to cell wall lysis; the cell membrane also remained intact. Analysis of transcriptional response data revealed that chitosan treatment leads to multiple changes in the expression profiles of Staphylococcus aureus SG511 genes involved in the regulation of stress and autolysis, as well as genes associated with energy metabolism. Finally, a possible mechanism for chitosan's activity is postulated. Although we contend that there might not be a single classical target that would explain chitosan's antimicrobial action, we speculate that binding of chitosan to teichoic acids, coupled with a potential extraction of membrane lipids (predominantly lipoteichoic acid) results in a sequence of events, ultimately leading to bacterial death.


1979 ◽  
pp. 45-76 ◽  
Author(s):  
C. M. Rivera ◽  
Donald Penner

1981 ◽  
Vol 36 (11-12) ◽  
pp. 988-996 ◽  
Author(s):  
Dietmar Dorn-Zachertz ◽  
Guido Zimmer

Abstract 1-anilino-naphthalene-8 -sulfonate (ANS) fluorescence measurements have revealed that red blood cell membrane of the Rhnull type undergoes a transition at about 16 °C. In contrast, viscosity measurements of the extracted membrane lipids showed the usually observed transition at about 18 °C. Lower values of titratable sulfhydryl (SH) groups were observed in Rhnull membrane using 5,5′-dithiobis-(2-nitro-benzoic-acid) (Nbs2). In contrast, disulfide bonds in Rhnull membrane were estimated to be about 3 times the value of the controls. Spin labeling experiments using 2-(3-carboxypropyl)-4, 4 dimethyl-2-tridecyl 3-oxazolidinyl-oxyl were carried out with phospholipase A2 modified membranes. The mobile part of the spectra was significantly increased on the Rhnull membrane. In the presence of ᴅ-glucose, infrared spectrometry showed a larger reduction of the intensity of the POO-band in Rhnull membrane. In contrast to controls, binding of the reagent diethylpyrocarbonate resulted in no significant changes of the Rhnull membrane as determined by electron spin resonance (ESR) measurements. ᴅ-glucose transport activity was found to be at the upper level of a group of Rh positive and Rh negative persons. It is suggested that the intensity of the polar protein-lipid interaction is reduced in Rhnull membrane.


Blood ◽  
1976 ◽  
Vol 47 (2) ◽  
pp. 189-195 ◽  
Author(s):  
TA Lane ◽  
SK Ballas ◽  
ER Burka

Abstract Human reticulocytes are capable of synthesizing membrane lipids from 14C-glycerol de novo. In both sickle and nonsickle reticulocytes the majority of 14C-glycerol was incorporated into phospholipids, primarily phosphatidylserine and phosphatidylcholine. Incorporation into sphingomyelin was minimal. The most abundant neutral lipid synthesized was triglyceride. In the absence of sickling, the rate of lipid synthesis in sickle reticulocytes was similar to that of nonsickle reticulocytes. With the induction of sickling under anoxic conditions sickle reticulocytes showed a prompt increase in the rate of lipid synthesis to an average of 69% above control values, while nonsickle reticulocytes under similar conditions decreased the rate of lipid synthesis. An increase in the rate of membrane lipid synthesis is associated in the mammalian erythroid cell with cell membrane damage. The findings further confirm that lesions of the erythroid cell membrane in sickle cell anemia are secondary to the sickling process itself.


2020 ◽  
Vol 21 (11) ◽  
pp. 3935 ◽  
Author(s):  
Kerstin Rastädter ◽  
David J. Wurm ◽  
Oliver Spadiut ◽  
Julian Quehenberger

The microbial cell membrane is affected by physicochemical parameters, such as temperature and pH, but also by the specific growth rate of the host organism. Homeoviscous adaption describes the process of maintaining membrane fluidity and permeability throughout these environmental changes. Archaea, and thereby, Sulfolobus spp. exhibit a unique lipid composition of ether lipids, which are altered in regard to the ratio of diether to tetraether lipids, number of cyclopentane rings and type of head groups, as a coping mechanism against environmental changes. The main biotechnological application of the membrane lipids of Sulfolobus spp. are so called archaeosomes. Archaeosomes are liposomes which are fully or partly generated from archaeal lipids and harbor the potential to be used as drug delivery systems for vaccines, proteins, peptides and nucleic acids. This review summarizes the influence of environmental parameters on the cell membrane of Sulfolobus spp. and the biotechnological applications of their membrane lipids.


1995 ◽  
Vol 65 (1) ◽  
pp. 56-58 ◽  
Author(s):  
A. Körner ◽  
S. Petrovic ◽  
H. Höcker

1982 ◽  
Vol 201 (3) ◽  
pp. 515-521 ◽  
Author(s):  
P S J Cheetham ◽  
P Dunnill ◽  
M D Lilly

The physical properties and the methods used for interconversion of three forms of cholesterol oxidase extracted from Nocardia rhodochrous by treatment with Triton X-100, trypsin or buffer alone provide evidence that these forms differ chiefly in the possession or absence of a hydrophobic anchor region connected by a trypsin-sensitive region. The hydrophobic domain normally integrates the enzyme into the cell membrane and confers amphipathic properties on the solubilized enzyme, causing adsorption to hydrophobic resins, aggregation when detergent is removed and formation of mixed micelles with detergent and cholesterol resulting in surface-dilution kinetic behaviour and activation by relatively high concentrations of water-miscible solvents. By contrast, only the enzymic fragment is extracted with trypsin and it behaves as a conventional soluble enzyme and does not aggregate or interact with hydrophobic resins, detergents or water-miscible solvents. As no phospholipid could be detected in the enzyme extracts, the detergent appears to act as a substitute for the cell-membrane lipids that would normally interact with the hydrophobic region. This cholesterol oxidase is an example of a prokaryotic enzyme possessing two closely associated catalytic functions, dehydrogenase and isomerase activities, and an anchoring function.


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