scholarly journals Transport of glycine betaine in the extremely haloalkaliphilic sulphur bacterium Ectothiorhodospira halochloris

1992 ◽  
Vol 138 (10) ◽  
pp. 1993-1998 ◽  
Author(s):  
P. Peters ◽  
E. Tel-Or ◽  
H. G. Truper
Keyword(s):  
Glycine Betaine ◽  
Ectothiorhodospira Halochloris

scholarly journals Characterization of Glycine SarcosineN-Methyltransferase and Sarcosine DimethylglycineN-Methyltransferase

2001 ◽  
Vol 67 (5) ◽  
pp. 2044-2050 ◽  
Author(s):  
Antti Nyyssölä ◽  
Tapani Reinikainen ◽  
Matti Leisola
Keyword(s):  
Escherichia Coli ◽  
Osmotic Pressure ◽  
Glycine Betaine ◽  
The Other ◽  
Substrate Specificities ◽  
Methyl Group ◽  
High Substrate ◽  
Ectothiorhodospira Halochloris ◽  
High Concentrations

ABSTRACT Glycine betaine is accumulated in cells living in high salt concentrations to balance the osmotic pressure. Glycine sarcosineN-methyltransferase (GSMT) and sarcosine dimethylglycineN-methyltransferase (SDMT) of Ectothiorhodospira halochloris catalyze the threefold methylation of glycine to betaine, with S-adenosylmethionine acting as the methyl group donor. These methyltransferases were expressed inEscherichia coli and purified, and some of their enzymatic properties were characterized. Both enzymes had high substrate specificities and pH optima near the physiological pH. No evidence of cofactors was found. The enzymes showed Michaelis-Menten kinetics for their substrates. The apparent Km andV max values were determined for all substrates when the other substrate was present in saturating concentrations. Both enzymes were strongly inhibited by the reaction productS-adenosylhomocysteine. Betaine inhibited the methylation reactions only at high concentrations.

Structural analysis of the photosynthetic membrane from Ectothiorhodospira halochloris

1983 ◽  
Vol 41 ◽  
pp. 740-741
Author(s):  
H. Engelhardt ◽  
R. Guckenberger ◽  
W. Baumeister
Keyword(s):  
Lattice Structure ◽  
Bacterial Species ◽  
Hexagonal Lattice ◽  
Reaction Centre ◽  
Photosynthetic Membrane ◽  
Rhodopseudomonas Viridis ◽  
Photosynthetic Membranes ◽  
Ectothiorhodospira Halochloris ◽  
Main Components

Bacterial photosynthetic membranes contain, apart from lipids and electron transport components, reaction centre (RC) and light harvesting (LH) polypeptides as the main components. The RC-LH complexes in Rhodopseudomonas viridis membranes are known since quite seme time to form a hexagonal lattice structure in vivo; hence this membrane attracted the particular attention of electron microscopists. Contrary to previous claims in the literature we found, however, that 2-D periodically organized photosynthetic membranes are not a unique feature of Rhodopseudomonas viridis. At least five bacterial species, all bacteriophyll b - containing, possess membranes with the RC-LH complexes regularly arrayed. All these membranes appear to have a similar lattice structure and fine-morphology. The lattice spacings of the Ectothiorhodospira haloohloris, Ectothiorhodospira abdelmalekii and Rhodopseudomonas viridis membranes are close to 13 nm, those of Thiocapsa pfennigii and Rhodopseudomonas sulfoviridis are slightly smaller (∼12.5 nm).

scholarly journals Application of Exogenous Protectants Mitigates Salt-Induced Na+ Toxicity and Sustains Cotton (Gossypium hirsutum L.) Seedling Growth: Comparison of Glycine Betaine and Salicylic Acid

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 380
Author(s):  
Abdoul Kader Mounkaila Hamani ◽  
Jinsai Chen ◽  
Mukesh Kumar Soothar ◽  
Guangshuai Wang ◽  
Xiaojun Shen ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Glycine Betaine ◽  
Growth Parameters ◽  
Biomass Accumulation ◽  
Nacl Stress ◽  
Soil Salinization ◽  
Sodium Toxicity ◽  
Negative Effect ◽  
Effective Conditions ◽  
A Current

Soil salinization adversely affects agricultural productivity. Mitigating the adverse effects of salinity represents a current major challenge for agricultural researchers worldwide. The effects of exogenously applied glycine betaine (GB) and salicylic acid (SA) on mitigating sodium toxicity and improving the growth of cotton seedlings subjected to salt stress remain unclear. The treatments in a phytotron included a control (CK, exogenously untreated, non-saline), two NaCl conditions (0 and 150 mM), four exogenous GB concentrations (0, 2.5, 5.0, and 7.5 mM), and four exogenous SA concentrations (0, 1.0, 1.5, and 2.0 mM). The shoot and roots exposed to 150 mM NaCl without supplementation had significantly higher Na+ and reduced K+, Ca2+, and Mg2+ contents, along with lowered biomass, compared with those of CK. Under NaCl stress, exogenous GB and SA at all concentrations substantially inversed these trends by improving ion uptake regulation and biomass accumulation compared with NaCl stress alone. Supplementation with 5.0 mM GB and with 1.0 mM SA under NaCl stress were the most effective conditions for mitigating Na+ toxicity and enhancing biomass accumulation. NaCl stress had a negative effect on plant growth parameters, including plant height, leaf area, leaf water potential, and total nitrogen (N) in the shoot and roots, which were improved by supplementation with 5.0 mM GB or 1.0 mM SA. Supplementation with 5.0 mM exogenous GB was more effective in controlling the percentage loss of conductivity (PLC) under NaCl stress.

Foliar Application of Abscisic Acid and Sulfonamide Compounds Induced Drought Tolerance in Watermelon

2015 ◽  
Vol 723 ◽  
pp. 705-710
Author(s):  
Wei Shun Cheng ◽  
Dan Li Zeng ◽  
Na Zhang ◽  
Hong Xia Zeng ◽  
Xian Feng Shi ◽  
...  
Keyword(s):  
Abscisic Acid ◽  
Drought Stress ◽  
Drought Tolerance ◽  
Ascorbate Peroxidase ◽  
Glycine Betaine ◽  
Foliar Application ◽  
Citrullus Lanatus ◽  
Recovery Phase ◽  
Daily Application

The effects of exogenous abscisic acid and two sulfonamide compounds: Sulfacetamide and Sulfasalazine were studied on tolerance of watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai var. lanatus] under drought stress and compared with abscisic acid effects. Eight-week old plants were treated with ABA (10 and 25 mg/L), Sulfacetamide (25, 50 and 100 mg/L) and Sulfasalazine (25,50 and 100 mg/L). Solutions were sprayed daily and sampling was done at 0 h, 48 h, 96 h, 144 h and 48 h after re-watering (recovery phase or 192 h). Treated plants showed relatively greater drought tolerance. This indicates that, Sulfacetamide and Sulfasalazine may improve resistance in watermelon, like ABA, increasing levels of proline, glycine betaine and malondialdehyde and the activity of ascorbate peroxidase. Daily application of Sulfasalazine and Sulfacetamide during drought stress period was effective in increasing watermelon plants tolerance to drought as was ABA.

scholarly journals BetS Is a Major Glycine Betaine/Proline Betaine Transporter Required for Early Osmotic Adjustment in Sinorhizobium meliloti

2002 ◽  
Vol 184 (10) ◽  
pp. 2654-2663 ◽  
Author(s):  
Alexandre Boscari ◽  
Karine Mandon ◽  
Laurence Dupont ◽  
Marie-Christine Poggi ◽  
Daniel Le Rudulier
Keyword(s):  
Glycine Betaine ◽  
Sinorhizobium Meliloti ◽  
Transport Systems ◽  
High Osmolarity ◽  
Carnitine Transporter ◽  
Rapid Acquisition ◽  
Common Structure ◽  
Pcr Product ◽  
Transport Kinetic ◽  
In Cells

ABSTRACT Hybridization to a PCR product derived from conserved betaine choline carnitine transporter (BCCT) sequences led to the identification of a 3.4-kb Sinorhizobium meliloti DNA segment encoding a protein (BetS) that displays significant sequence identities to the choline transporter BetT of Escherichia coli (34%) and to the glycine betaine transporter OpuD of Bacillus subtilis (30%). Although the BetS protein shows a common structure with BCCT systems, it possesses an unusually long hydrophilic C-terminal extension (169 amino acids). After heterologous expression of betS in E. coli mutant strain MKH13, which lacks choline, glycine betaine, and proline transport systems, both glycine betaine and proline betaine uptake were restored, but only in cells grown at high osmolarity or subjected to a sudden osmotic upshock. Competition experiments demonstrated that choline, ectoine, carnitine, and proline were not effective competitors for BetS-mediated betaine transport. Kinetic analysis revealed that BetS has a high affinity for betaines, with Km s of 16 ± 2 μM and 56 ± 6 μM for glycine betaine and proline betaine, respectively, in cells grown in minimal medium with 0.3 M NaCl. BetS activity appears to be Na+ driven. In an S. meliloti betS mutant, glycine betaine and proline betaine uptake was reduced by about 60%, suggesting that BetS represents a major component of the overall betaine uptake activities in response to salt stress. β-Galactosidase activities of a betS-lacZ strain grown in various conditions showed that betS is constitutively expressed. Osmotic upshock experiments performed with wild-type and betS mutant cells, treated or not with chloramphenicol, indicated that BetS-mediated betaine uptake is the consequence of immediate activation of existing proteins by high osmolarity, most likely through posttranslational activation. Growth experiments underscored the crucial role of BetS as an emerging system involved in the rapid acquisition of betaines by S. meliloti subjected to osmotic upshock.

Accumulation of natural and synthetic betaines by a mammalian renal cell line

1996 ◽  
Vol 74 (2) ◽  
pp. 283-287 ◽  
Author(s):  
K. Randall ◽  
M. Lever ◽  
B. A. Peddie ◽  
S. T. Chambers
Keyword(s):  
Osmotic Stress ◽  
Glycine Betaine ◽  
Mdck Cells ◽  
Intracellular Accumulation ◽  
Madin Darby Canine Kidney ◽  
Renal Cell Line ◽  
High Concentrations ◽  
Inhibition Studies ◽  
Darby Canine Kidney ◽  
Canine Kidney

Intracellular accumulation of different betaines was compared in osmotically stressed Madin Darby canine kidney (MDCK) cells to model the betaine accumulation specificity of the mammalian inner medulla and to show how this accumulation differed from that of bacteria. All betaines accumulated less than glycine betaine. Arsenobetaine (the arsenic analogue of glycine betaine) accumulated to 12% of the glycine betaine levels and the sulphur analogue dimethylthetin accumulated to >80%. Most substituted glycine betaine analogues accumulated to 2–5% of intracellular glycine betaine concentrations, however, serine betaine accumulated to <0.5% of glycine betaine levels. Inhibition studies to distinguish the betaine ports were performed by the addition of proline. Butyrobetaine and carnitine accumulation was not proline sensitive, whereas that of omer betaines was. As with glycine betaine, the accumulation of propionobetaine and dimethylthetin was proline sensitive and osmoregulated. Pyridinium betaine was accumulated by both proline-sensitive and -insensitive systems, with a small increase under osmotic stress. High concentrations (10 times that of glycine betaine) of the dietary betaines proline betaine and trigonelline inhibited total betaine accumulation. Because α-substituted betaines are accumulated by bacteria and not by MDCK cells, these betaines may be the basis for design of antimicrobial agents.Key words: MDCK cells, betaine accumulation, osmolytes, betaine analogues.

scholarly journals Gbu Glycine Betaine Porter and Carnitine Uptake in Osmotically Stressed Listeria monocytogenes Cells

2002 ◽  
Vol 68 (11) ◽  
pp. 5647-5655 ◽  
Author(s):  
Mary Lou Mendum ◽  
Linda Tombras Smith
Keyword(s):  
Listeria Monocytogenes ◽  
Transport System ◽  
Glycine Betaine ◽  
Compatible Solutes ◽  
High Salt ◽  
Uptake System ◽  
Food Borne ◽  
Protein Mutants ◽  
Carnitine Uptake ◽  
Do So

ABSTRACT The food-borne pathogen Listeria monocytogenes grows actively under high-salt conditions by accumulating compatible solutes such as glycine betaine and carnitine from the medium. We report here that the dominant transport system for glycine betaine uptake, the Gbu porter, may act as a secondary uptake system for carnitine, with a Km of 4 mM for carnitine uptake and measurable uptake at carnitine concentrations as low as 10 μM. This porter has a Km for glycine betaine uptake of about 6 μM. The dedicated carnitine porter, OpuC, has a Km for carnitine uptake of 1 to 3 μM and a V max of approximately 15 nmol/min/mg of protein. Mutants lacking either opuC or gbu were used to study the effects of four carnitine analogs on growth and uptake of osmolytes. In strain DP-L1044, which had OpuC and the two glycine betaine porters Gbu and BetL, triethylglycine was most effective in inhibiting growth in the presence of glycine betaine, but trigonelline was best at inhibiting growth in the presence of carnitine. Carnitine uptake through OpuC was inhibited by γ-butyrobetaine. Dimethylglycine inhibited both glycine betaine and carnitine uptake through the Gbu porter. Carnitine uptake through the Gbu porter was inhibited by triethylglycine. Glycine betaine uptake through the BetL porter was strongly inhibited by trigonelline and triethylglycine. These results suggest that it is possible to reduce the growth of L. monocytogenes under osmotically stressful conditions by inhibiting glycine betaine and carnitine uptake but that to do so, multiple uptake systems must be affected.

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