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.

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.

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.

Role of adenosine for reactive hyperemia in normal and stunned porcine myocardium

1992 ◽  
Vol 263 (4) ◽  
pp. H1119-H1127 ◽  
Author(s):  
K. A. Kirkeboen ◽  
G. Aksnes ◽  
K. Lande ◽  
A. Ilebekk
Keyword(s):  
Adenosine Deaminase ◽  
Reactive Hyperemia ◽  
Nucleoside Transport ◽  
Normal Myocardium ◽  
Stunned Myocardium ◽  
Segment Length ◽  
Doppler Flowmetry ◽  
Reduced Volume ◽  
Adenosine Concentration

The role of adenosine for reactive hyperemia in normal and stunned myocardium was examined in 16 open-chest barbiturate-anesthetized pigs. Interstitial adenosine concentration was reduced or enhanced by intracoronary infusion of adenosine deaminase or the nucleoside transport inhibitor R 75231, respectively. In normal myocardium, adenosine deaminase reduced volume of hyperemia (Doppler flowmetry) after a 30-s left anterior descending coronary artery (LAD) occlusion by 20% (6-34%; P < 0.05), whereas R 75231 increased volume of hyperemia by 15% (2-24%; P < 0.05). Adenosine deaminase reduced volume of hyperemia after a 2-min LAD occlusion by 27% (13-37%; P < 0.001), whereas R 75231 increased volume of hyperemia by 66% (53-159%; P < 0.001). Adenosine deaminase and R 75231 did not affect maximal hyperemia. Volume of hyperemia after a 2-min LAD occlusion was reduced in stunned myocardium (%systolic segment length shortening reduced by approximately 45%, ultrasonic technique) but not further altered by either adenosine deaminase or R 75231. These findings show that adenosine contributes to reactive hyperemia after 30-120 s of ischemia in normal myocardium and indicate that the reduced reactive hyperemia in stunned myocardium is due to reduced accumulation of adenosine during ischemia.

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 L-Arginine Intake Effect on Adenine Nucleotide Metabolism in Rat Parenchymal and Reproductive Tissues

2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
G. Kocic ◽  
J. Nikolic ◽  
T. Jevtovic-Stoimenov ◽  
D. Sokolovic ◽  
H. Kocic ◽  
...  
Keyword(s):  
Adenosine Deaminase ◽  
Adenine Nucleotide ◽  
Adenine Nucleotides ◽  
Tissue Growth ◽  
Nucleotide Metabolism ◽  
Amp Deaminase ◽  
Male Impotence ◽  
Adenine Nucleotide Metabolism ◽  
Adenosine Concentration ◽  
Male Wistar Rats

L-arginine is conditionally essetcial amino acid, required for normal cell growth, protein synthesis, ammonia detoxification, tissue growth and general performance, proposed in the treatment of men sterility and prevention of male impotence. The aim of the present paper was to estimate the activity of the enzymes of adenine nucleotide metabolism:5′-nucleotidase (5′-NU), adenosine deaminase (ADA), AMP deaminase, and xanthine oxidase (XO), during dietary intake of L-arginine for a period of four weeks of male Wistar rats. Adenosine concentration in tissues is maintained by the relative activities of the adenosine-producing enzyme,5′-NU and the adenosine-degrading enzyme-ADA adenosine deaminase. Dietary L-arginine intake directed adenine nucleotide metabolism in liver, kidney, and testis tissue toward the activation of adenosine production, by increased5′-NU activity and decreased ADA activity. Stimulation of adenosine accumulation could be of importance in mediating arginine antiatherosclerotic, vasoactive, immunomodulatory, and antioxidant effects. Assuming that the XO activity reflects the rate of purine catabolism in the cell, while the activity of AMP deaminase is of importance in ATP regeneration, reduced activity of XO, together with the increased AMP-deaminase activity, may suggest that adenine nucleotides are presumably directed to the ATP regenerating process during dietary L-arginine intake.

scholarly journals Characterization of sodium-dependent and sodium-independent nucleoside transport systems in rabbit brush-border and basolateral plasma-membrane vesicles from the renal outer cortex

1989 ◽  
Vol 264 (1) ◽  
pp. 223-231 ◽  
Author(s):  
T C Williams ◽  
A J Doherty ◽  
D A Griffith ◽  
S M Jarvis
Keyword(s):  
Brush Border ◽  
Basolateral Membrane ◽  
Membrane Vesicles ◽  
Nucleoside Transport ◽  
Transport Systems ◽  
Facilitated Diffusion ◽  
Basolateral Membrane Vesicles ◽  
Plasma Membrane Vesicles ◽  
Outer Cortex ◽  
Overshoot Phenomenon

The transport of uridine into rabbit renal outer-cortical brush-border and basolateral membrane vesicles was compared at 22 degrees C. Uridine was taken up into an osmotically active space in the absence of metabolism for both types of membrane vesicles. Uridine influx by brush-border membrane vesicles was stimulated by Na+, and in the presence of inwardly directed gradients of Na+ a transient overshoot phenomenon was observed, indicating active transport. Kinetic analysis of the saturable Na+-dependent component of uridine flux indicated that it was consistent with Michaelis-Menten kinetics (Km 12 +/- 3 microM, Vmax. 3.9 +/- 0.9 pmol/s per mg of protein). The sodium:uridine coupling stoichiometry was found to be consistent with 1:1 and involved the net transfer of positive charge. In contrast, uridine influx by basolateral membrane vesicles was not dependent on the cation present and was inhibited by nitrobenzylthioinosine (NBMPR). NBMPR-sensitive uridine transport was saturable (Km 137 +/- 20 microM, Vmax. 5.2 +/- 0.6 pmol/s per mg of protein). Inhibition of uridine flux by NBMPR was associated with high-affinity binding of NBMPR to the basolateral membrane (Kd 0.74 +/- 0.46 nM). Binding of NBMPR to these sites was competitively blocked by adenosine and uridine. These results indicate that uridine crosses the brush-border surface of rabbit proximal renal tubule cells by Na+-dependent pathways, but permeates the basolateral surface by NBMPR-sensitive facilitated-diffusion carriers.

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