Passive diffusion of nucleosides into Micrococcus sodonensis membrane vesicles

1980 ◽  
Vol 58 (6) ◽  
pp. 457-460 ◽  
Author(s):  
M. A. Pickard
Keyword(s):  
Energy Source ◽  
Membrane Vesicles ◽  
Passive Diffusion ◽  
Membrane Bound ◽  
Nucleoside Uptake ◽  
Membrane Bound Enzymes ◽  
Isolated Membrane Vesicles

Nucleoside entry into isolated membrane vesicles of Micrococcus sodonensis (luteus) was studied using 14C-labelled nucleosides: adenosine, inosine, cytidine, uridine, guanosine, and thymidine. All nucleosides were recovered unmetabolized from the vesicles except adenosine and cytidine which were partly deaminated by membrane-bound enzymes. Vesicle preparations actively transported proline but no energy source was found capable of supporting concentrative nucleoside uptake. The entry of nucleosides into M. sodonensis vesicles was not saturable, nor was there competition between the nucleosides studied for entry. It was concluded that nucleoside entry into M. sodonensis vesicles occurs by passive diffusion.

Purification and Some Properties of the Soluble and Membrane-Bound Adenosine Deaminases of Micrococcus sodonensis ATCC 11880 and their Distribution within the Family Micrococcaceae

1975 ◽  
Vol 53 (3) ◽  
pp. 344-353 ◽  
Author(s):  
M. A. Pickard
Keyword(s):  
Adenosine Deaminase ◽  
Gel Filtration ◽  
Membrane Vesicles ◽  
Soluble Enzyme ◽  
Adenosine Deaminases ◽  
Adenosine Deaminase Activity ◽  
The Family ◽  
Adenosine Transport ◽  
Membrane Bound ◽  
Isolated Membrane Vesicles

In Micrococcus sodonensis and some other Micrococcus species, adenosine deaminase is present both as a membrane-bound and a soluble enzyme. The membrane-bound adenosine deaminase can be extracted with n-butanol, and may account for up to 5% of the total cellular adenosine deaminase activity. In a number of comparative tests, no differences between the two enzyme forms could be found, thus they are believed to be similar molecular species. The purified membrane-bound or soluble enzyme had a molecular weight, obtained by gel-filtration, of 130 000 and was inactive toward adenine and adenine mononucleotides. It appears, therefore, to be more closely related to the calf-intestine enzyme than the Aspergillus oryzae form in respect to size and substrate specificity. Attempts to correlate membrane-bound adenosine deaminase activity with adenosine transport in isolated membrane vesicles of M. sodonensis indicated no obvious relationship between the two activities.

Metabolism and Transport of Purine Nucleosides by Membrane Preparations of Micrococcus sodonensis

1974 ◽  
Vol 52 (2) ◽  
pp. 83-89 ◽  
Author(s):  
M. A. Pickard ◽  
Lucille Phillippe ◽  
J. N. Campbell
Keyword(s):  
Adenosine Deaminase ◽  
Membrane Vesicles ◽  
Purine Nucleoside ◽  
Nucleoside Transport ◽  
Marked Contrast ◽  
Adenosine Concentration ◽  
Membrane Bound ◽  
Uptake And Metabolism ◽  
Isolated Membrane Vesicles ◽  
Bacterial Systems

The uptake and metabolism of adenosine-8-14C was studied using isolated membrane vesicles prepared from Micrococcus sodonensis. When the adenosine concentration was 1.0 mM, a concentration that caused prolonged bacteriostasis in growing cells, the membranes vesicles initially accumulated adenosine and inosine to similar levels but rapidly became enriched with inosine. However, when the external adenosine concentration was lowered to 0.1 mM, the vesicle contents were almost entirely inosine. No compounds other than adenosine and inosine were detected. These effects were shown to be the result of a membrane-bound adenosine deaminase and are in marked contrast to the phosphoribosyltransferase-linked mechanisms of purine nucleoside transport in other bacterial systems.

Some Aspects of the Polyhexamethyleneguanidine Salts Effect on Cell Cultures

2014 ◽  
Vol 1 (1) ◽  
pp. 62-67 ◽  
Author(s):  
M. Mandygra ◽  
A. Lysytsia
Keyword(s):  
Proliferative Activity ◽  
Cell Monolayer ◽  
Eukaryotic Cell ◽  
Culture Methods ◽  
Cellular Processes ◽  
Negative Effect ◽  
Membrane Bound ◽  
Membrane Bound Enzymes ◽  
Anion Type ◽  
Cell Culture Methods

Aim. To investigate the effect of polyhexamethyleneguanidine (PHMG) to eukaryotic cell culture. Methods. The passaged bovine tracheal cells culture (TCC) and primary culture of chicken embryo fi broblasts (FCE) were used in the experiments. TCC and FCE monolayers were treated with aqueous solutions of PHMG chloride or succinate. The method of PHMG polycation adsorption to the cells’ plasma membrane together with microscopy were applied. Results. The dependence of PHMG effect on the eukaryotic cells on the agent concentration, duration of exposure and the anion type has been fi xed. The PHMG concentration of 10 –5 per cent (0.1 μg/ml) never causes degradation of the previously formed cell monolayer, while the higher concentrations damage it. The conditions of the PHMG chloride and succinate’s negative effect on cell proliferation and inhibition of monolayer formation were determined. The hypothesis that under certain conditions PHMG stimulates the proliferative activity of the cells has been confi rmed. Stimulation may be associated with non-specifi c stress adaptation of cells. In this case, it is due to modifi cations of the cell membrane after PHMG adsorption to it. Conclusions. PHMG polycation binds with the membrane’s phosphoglycerides fi rmly and irreversibly. A portion of the lipids are removed from participation in the normal cellular processes at that. At the same time, the synthesis of new lipids and membrane-bound enzymes is probably accelerated. The phospholip ids’ neogenesis acceleration can stimulate mitosis under certain conditions. The obtained results can be used in the biotechnologies.

Rotavirus interaction with isolated membrane vesicles.

1994 ◽  
Vol 68 (6) ◽  
pp. 4009-4016 ◽  
Author(s):  
M C Ruiz ◽  
S R Alonso-Torre ◽  
A Charpilienne ◽  
M Vasseur ◽  
F Michelangeli ◽  
...  
Keyword(s):  
Membrane Vesicles ◽  
Isolated Membrane Vesicles

scholarly journals Improving cell-free glycoprotein synthesis by characterizing and enriching native membrane vesicles

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jasmine M. Hershewe ◽  
Katherine F. Warfel ◽  
Shaelyn M. Iyer ◽  
Justin A. Peruzzi ◽  
Claretta J. Sullivan ◽  
...  
Keyword(s):  
Gene Expression ◽  
Escherichia Coli ◽  
Synthetic Biology ◽  
Membrane Protein ◽  
Membrane Vesicles ◽  
Processing Methods ◽  
Glycoprotein Synthesis ◽  
On Demand ◽  
Free Gene ◽  
Membrane Bound

AbstractCell-free gene expression (CFE) systems from crude cellular extracts have attracted much attention for biomanufacturing and synthetic biology. However, activating membrane-dependent functionality of cell-derived vesicles in bacterial CFE systems has been limited. Here, we address this limitation by characterizing native membrane vesicles in Escherichia coli-based CFE extracts and describing methods to enrich vesicles with heterologous, membrane-bound machinery. As a model, we focus on bacterial glycoengineering. We first use multiple, orthogonal techniques to characterize vesicles and show how extract processing methods can be used to increase concentrations of membrane vesicles in CFE systems. Then, we show that extracts enriched in vesicle number also display enhanced concentrations of heterologous membrane protein cargo. Finally, we apply our methods to enrich membrane-bound oligosaccharyltransferases and lipid-linked oligosaccharides for improving cell-free N-linked and O-linked glycoprotein synthesis. We anticipate that these methods will facilitate on-demand glycoprotein production and enable new CFE systems with membrane-associated activities.

scholarly journals Regulation of membrane-bound enzymes of glycosphingolipid biosynthesis

1984 ◽  
Vol 25 (13) ◽  
pp. 1541-1547
Author(s):  
J D Burczak ◽  
R M Soltysiak ◽  
C C Sweeley
Keyword(s):  
Membrane Bound ◽  
Membrane Bound Enzymes ◽  
Glycosphingolipid Biosynthesis
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