Absence of glucokinase in Methanomonas sp. as a cause for their inability to grow on glucose

1972 ◽  
Vol 18 (12) ◽  
pp. 1907-1913 ◽  
Author(s):  
Kei Amemiya
Keyword(s):  
Phosphate Esters ◽  
Resting Cells ◽  
Obligate Methylotroph ◽  
Enzymatic Assays ◽  
Autotrophic Bacteria ◽  
Toxic Product ◽  
A Cell ◽  
Flow Through ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Autotrophic Bacterium

Many obligate autotrophic bacteria can be grown on glucose using a dialysis flow-through system. Methanomonas methanooxidans, an obligate methylotroph, exhibits many of the properties of an obligate autotrophic bacterium but we have been unable to grow it on glucose using dialysis. In the obligate autotrophic bacteria, the dialysis procedure seems to be removing a toxic product of glucose metabolism but this does not seem to be the case with the methylotroph. Enzymatic assays on a cell-free extract from methane-grown or methane plus glucose-grown cells showed only phosphoglucoisomerase activity, while glucokinase and glucose-6-phosphate dehydrogenase activity were not detected. Studies with resting cells showed that glucose was not oxidized, although the phosphate esters of glucose, fructose, ribose, and gluconate were oxidized. CO2 fixation occurred only in the presence of glucose-6-phosphate. The rate of oxygen consumed and CO2 fixed on glucose-6-phosphate were almost identical with that when methanol was used as the substrate. When the phosphate esters of glucose, fructose, and ribose were used as the sole energy source, only glucose-6-phosphate supported growth to any extent; in fact, the amount of growth was essentially the same as that obtained with methanol. The results from this study suggest that the inability of this organism to grow on glucose may be due to the absence of adequate glucokinase.

scholarly journals THE PRESENCE OF AN ENDOGENOUS RESPIRATION IN THE AUTOTROPHIC BACTERIA

1942 ◽  
Vol 25 (4) ◽  
pp. 617-622 ◽  
Author(s):  
K. G. Vogler
Keyword(s):  
Oxygen Uptake ◽  
Organic Materials ◽  
Endogenous Respiration ◽  
Thiobacillus Thiooxidans ◽  
Autotrophic Bacteria ◽  
Autotrophic Bacterium

It is shown that there exists in the autotrophic bacterium Thiobacillus thiooxidans a measurable oxygen uptake in the absence of the specific nutrient (sulfur). This respiration is shown to be due to the utilization of organic materials which must have been previously synthesized by the chemosynthetic process, providing evidence that autotrophic bacteria contain a dissimilatory process which involves the breakdown of organic materials and furnishes energy for the maintenance of the cell during periods in which the specific nutrient is absent. This is entirely in accord with the work of Bömeke (1939), who provided similar types of proof for Nitrosomonas and Nitrobacter. One may conclude, therefore, that autotrophic bacteria possess an endogenous respiration which involves the utilization of previously synthesized organic materials.

Perchlorate Reduction by Autotrophic Bacteria Attached to Zerovalent Iron in a Flow-Through Reactor

2007 ◽  
Vol 41 (3) ◽  
pp. 990-997 ◽  
Author(s):  
Xueyuan Yu ◽  
Christopher Amrhein ◽  
Marc A. Deshusses ◽  
Mark R. Matsumoto
Keyword(s):  
Zerovalent Iron ◽  
Perchlorate Reduction ◽  
Autotrophic Bacteria ◽  
Flow Through

scholarly journals Site-Specific Cleavage of RNAs Derived from the PIM1 3′-UTR by a Metal-Free Artificial Ribonuclease

Molecules ◽  
2019 ◽  
Vol 24 (4) ◽  
pp. 807 ◽  
Author(s):  
Felix Zellmann ◽  
Laura Thomas ◽  
Ute Scheffer ◽  
Roland Hartmann ◽  
Michael Göbel
Keyword(s):  
Competitive Inhibition ◽  
Reaction Rates ◽  
Phosphate Esters ◽  
Rna Cleavage ◽  
Site Specificity ◽  
Cleavage Rate ◽  
Short Oligonucleotide ◽  
A Cell ◽  
Artificial Nuclease ◽  
Oligonucleotide Conjugates

Oligonucleotide conjugates of tris(2-aminobenzimidazole) have been reported previously to cleave complementary RNA strands with high levels of sequence and site specificity. The RNA substrates used in these studies were oligonucleotides not longer than 29-mers. Here we show that ~150–400-mer model transcripts derived from the 3′-untranslated region of the PIM1 mRNA reacted with rates and specificities comparable to those of short oligonucleotide substrates. The replacement of DNA by DNA/LNA mixmers further increased the cleavage rate. Tris(2-aminobenzimidazoles) were designed to interact with phosphates and phosphate esters. A cell, however, contains large amounts of phosphorylated species that may cause competitive inhibition of RNA cleavage. It is thus important to note that no loss in reaction rates was observed in phosphate buffer. This opens the way to in-cell applications for this type of artificial nuclease. Furthermore, we disclose a new synthetic method giving access to tris(2-aminobenzimidazoles) in multigram amounts.

scholarly journals Involvement of p40phox in activation of phagocyte NADPH oxidase through association of its carboxyl-terminal, but not its amino-terminal, with p67phox.

1996 ◽  
Vol 184 (3) ◽  
pp. 893-902 ◽  
Author(s):  
S Tsunawaki ◽  
S Kagara ◽  
K Yoshikawa ◽  
L S Yoshida ◽  
T Kuratsuji ◽  
...  
Keyword(s):  
Nadph Oxidase ◽  
Inhibitory Effect ◽  
Human Neutrophils ◽  
Resting Cells ◽  
Amino Terminal ◽  
Src Homology 3 ◽  
Phagocyte Nadph Oxidase ◽  
A Cell ◽  
Src Homology ◽  
Tight Association

Phagocyte NADPH oxidase, dormant in resting cells, is activated upon cell stimulation to produce superoxide anion, a precursor of microbicidal oxidants. Active NADPH oxidase is found on the membrane as an enzyme complex, composed of membrane-integrated cytochrome b558 (gp91phox and p22phox subunits) and two cytosolic factors (p47phox and p67phox), each of the latter containing two src homology 3 (SH3) domains. Recently, we radioactively identified a third cytosolic factor, p40phox, as a molecule that associates with p67phox in human neutrophils. Although it has been found that this p40phox protein is defective in patients with chronic granulomatous disease (CGD) who lack p67phox, evidence to functionally relate it to the NADPH oxidase system has hitherto been lacking. In this study, we raised separate antibodies against both the COOH- and NH2-terminal polypeptides of p40phox as well as against the COOH-terminal polypeptide of p67phox to examine the mode of interaction between p40phox and p67phox in a complex. The antibody against the COOH terminus of p67phox was able to communoprecipitate p40phox in conjunction with p67phox itself as was expected. Very interestingly, however, the antibody against the COOH terminus of p40phox completely dissociated the p67phox molecule from the p40phox-p67phox complex unit without any detectable coimmunoprecipitation of p67phox, despite their tight association, whereas that against the NH2 terminus of p40phox had absolutely no dissociation effect. Similar results were found regarding their effects on the O2-generating ability of cytosol in a cell-free activation system, i.e., inhibition was noted with the COOH terminus antibody but not with that for the NH2 terminus of p40phox. However, this dissociation did not affect the translocation of the cytosolic components including p47phox to the membrane. Once the NADPH oxidase was activated, the antibody for the COOH terminus did not show any inhibitory effect on catalysis by the activated enzyme. The stimulators of NADPH oxidase, MA and SDS, did not dissociate the p40phox-p67phox complex. These results provide the first demonstration that p40phox is practically involved in the activation of NADPH oxidase through the association of its COOH-terminal, but not its NH2-terminal, with p67phox.

Mechanism of Action of Divicine in a Cell-free System and in Glucose-6-phosphate Dehydrogenase-deficient Red Cells

1984 ◽  
Vol 12 (4) ◽  
pp. 331-336 ◽  
Author(s):  
Margaret A. Baker ◽  
Amalia Bosia ◽  
Gianpiero Pescarmona ◽  
Franco Turrini ◽  
Paolo Arese
Keyword(s):  
Mechanism Of Action ◽  
Red Cells ◽  
Free System ◽  
Cell Free System ◽  
A Cell ◽  
Glucose 6 Phosphate Dehydrogenase

scholarly journals Evidence that essential thrombocythemia is a clonal disorder with origin in a multipotent stem cell

Blood ◽  
1981 ◽  
Vol 58 (5) ◽  
pp. 916-919 ◽  
Author(s):  
PJ Fialkow ◽  
GB Faguet ◽  
RJ Jacobson ◽  
K Vaidya ◽  
S Murphy
Keyword(s):  
Stem Cell ◽  
Essential Thrombocythemia ◽  
Myelogenous Leukemia ◽  
Hematopoietic Tissue ◽  
Multipotent Stem Cells ◽  
Myeloid Metaplasia ◽  
Multipotent Stem Cell ◽  
Agnogenic Myeloid Metaplasia ◽  
A Cell ◽  
Glucose 6 Phosphate Dehydrogenase

Essential thrombocythemia is characterized by proliferation of hematopoietic tissue predominantly involving megakaryocytes and resulting in marked thrombocytosis. The disorder has some clinical and laboratory features that resemble those seen in the clonal multipotent stem cell disorders chronic myelogenous leukemia, polycythemia vera, and agnogenic myeloid metaplasia. It has been argued that essential thrombocythemia should be classified together with those disorders as a myeloproliferative syndrome. However, without knowledge of the numbers and types of cells that are involved in essential thrombocythemia, this suggestion remains speculative. Three patients with thrombocytosis were studied. The diagnosis of essential thrombocythemia was considered to be firm in two patients and probable in the third one. The X-linked glucose-6-phosphate dehydrogenase locus was used as a cell marker. Whereas both A and B types of glucose-6-phosphate dehydrogenase were found in nonhematopoietic tissues, only a single-enzyme type was found in the granulocytes, red cells, and platelets from each patient. These data indicate that the disorders in these three patients are clonal and involve multipotent stem cells.

scholarly journals Evidence that essential thrombocythemia is a clonal disorder with origin in a multipotent stem cell

Blood ◽  
1981 ◽  
Vol 58 (5) ◽  
pp. 916-919 ◽  
Author(s):  
PJ Fialkow ◽  
GB Faguet ◽  
RJ Jacobson ◽  
K Vaidya ◽  
S Murphy
Keyword(s):  
Stem Cell ◽  
Essential Thrombocythemia ◽  
Myelogenous Leukemia ◽  
Hematopoietic Tissue ◽  
Multipotent Stem Cells ◽  
Myeloid Metaplasia ◽  
Multipotent Stem Cell ◽  
Agnogenic Myeloid Metaplasia ◽  
A Cell ◽  
Glucose 6 Phosphate Dehydrogenase

Abstract Essential thrombocythemia is characterized by proliferation of hematopoietic tissue predominantly involving megakaryocytes and resulting in marked thrombocytosis. The disorder has some clinical and laboratory features that resemble those seen in the clonal multipotent stem cell disorders chronic myelogenous leukemia, polycythemia vera, and agnogenic myeloid metaplasia. It has been argued that essential thrombocythemia should be classified together with those disorders as a myeloproliferative syndrome. However, without knowledge of the numbers and types of cells that are involved in essential thrombocythemia, this suggestion remains speculative. Three patients with thrombocytosis were studied. The diagnosis of essential thrombocythemia was considered to be firm in two patients and probable in the third one. The X-linked glucose-6-phosphate dehydrogenase locus was used as a cell marker. Whereas both A and B types of glucose-6-phosphate dehydrogenase were found in nonhematopoietic tissues, only a single-enzyme type was found in the granulocytes, red cells, and platelets from each patient. These data indicate that the disorders in these three patients are clonal and involve multipotent stem cells.

A Microfabricated Chip for the Study of Cell Electroporation

2000 ◽  
Author(s):  
Yong Huang ◽  
Boris Rubinsky
Keyword(s):  
Silicon Nitride ◽  
Cell Membrane ◽  
Irreversible Electroporation ◽  
Biological Cells ◽  
Cell Electroporation ◽  
Electrical Potentials ◽  
Silicon Nitride Membrane ◽  
Micro Hole ◽  
A Cell ◽  
Flow Through

Abstract It has been observed that when certain electrical potentials are applied across a cell they can induce the formation of pores in the cell membrane and consequently increase the permeability of the cell to macromolecules. This phenomenon is known as electroporation. Since the first report on gene transfer by electroporation1, it has become a standard method for introduction of macromolecules into cells2 3 4. Currently, electroporation is normally done in batches of cells between electrodes and there is little control over the permeabilization of individual cells. Therefore, it is very difficult to study the fundamental biophysics of cell membrane electro-permeabilization and to design optimal electroporation protocols for individual cells2 3 . Although the biophysics of electroporation are still not fully understood, indirect evidence shows that micro aqueous pores with diameters of tens to hundreds of angstroms are created in the cell membrane due to the electrical field induced structural rearrangement of the lipid bilayer5. It occurred to us that if electroporation induces pores in the cell membrane, then in a state of electroporation, a measurable current should flow through the individual cell. From this idea, we have developed a new micro-electroporation technology that employs a “bionic” chip to study and control the electroporation process in individual cells. The micro-electroporation chip, shown schematically in Figure 1, is designed and fabricated using standard silicon microfabrication technology. Each chip is a three-layer device that consists of two translucent poly silicon electrodes and a silicon nitride membrane, which all together form two fluid chambers. The two chambers are interconnected only through a micro hole through the dielectric silicon nitride membrane. In a typical process, the two chambers are filled with conductive solutions and one chamber contains biological cells. Individual cells can be captured in the micro hole and thus incorporated into the electrical circuit between the two electrodes of the chip. When the cell is in its normal state no current flows through the insulating lipid bilayer and consequently between the electrodes. However, when the electrical potential across the electrodes is sufficient to induce electroporation, a measurable current will flow through the pores of the cell membrane and between the electrodes. Measuring the currents through the bionic chip in real time will reveal the information of the state of electropermeabilization in cell membrane. The breakdown potential of irreversible electroporation, the most critical parameter in electroporation process, can be detected by analyzing current signals as well. Figure 2 illustrates a typical electrical signature in an irreversible electroporation process. Once the target cell is electroporated by the application of sufficient electroporation electrical potentials, macromolecules that are normally impermeant to cell membrane can be uploaded into the cell. Figure 3 shows how a cell entrapped in a hole is loaded during electroporation with a fluorescent die. With the ability to manipulate individual cells and detect the electrical potentials that induce electroporation in each cell, the chip can be used to study the fundamental biophysics of membrane electropermeabilization on the single cell level and in biotechnology, for controlled introduction of macromolecules, such as DNA fragments, into individual cells. We anticipate that this new technology will change the way in which electroporation is done and will provide key understanding of the biophysical processes that lead to cell electroporation. This paper will discuss the design, fabrication of the micro-electroporation chip, the experiment system as well as experiments carried out to precisely detect the parameters of electroporation of individual biological cells.

scholarly journals STUDIES ON THE METABOLISM OF AUTOTROPHIC BACTERIA

1942 ◽  
Vol 26 (1) ◽  
pp. 89-102 ◽  
Author(s):  
K. G. Vogler ◽  
G. A. LePage ◽  
W. W. Umbreit
Keyword(s):  
Sulfuric Acid ◽  
Organic Acids ◽  
Bacterial Cell ◽  
Sulfur Oxidation ◽  
Energy Of Activation ◽  
Detectable Effect ◽  
Intact Cells ◽  
Thiobacillus Thiooxidans ◽  
Autotrophic Bacteria ◽  
Autotrophic Bacterium

The data of this paper indicate that: 1. The "energy of activation" (µ) of sulfur oxidation by the autotrophic bacterium, Thiobacillus thiooxidans, is similar to that of other respirations. 2. The pH of the menstruum does not influence the respiration on sulfur between the limits of pH 2 to 4.8 once contact between the bacterial cell and the sulfur particle has been established but it does influence the rate at which such contact occurs. 3. The pO2 has little effect upon the respiration of this organism. 4. Most organic materials have no detectable effect upon the respiration of Thiobacillus thiooxidans, but the organic acids of terminal respiration seem to stimulate the respiration in the absence of oxidizable sulfur and certain of them inhibit sulfur oxidation. 5. In so far as inhibitor studies on intact cells are trustworthy, sulfur oxidation goes through iron-containing systems similar to cytochrome. It is possible that the oxygen contained in the sulfuric acid formed during sulfur oxidation is derived from the oxygen of the water.

scholarly journals Glucose-6-Phosphate Dehydrogenase Regulation in Anoxia Tolerance of the Freshwater Crayfish Orconectes virilis

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Benjamin Lant ◽  
Kenneth B. Storey
Keyword(s):  
Protein Kinase ◽  
Antioxidant Defense ◽  
Pentose Phosphate ◽  
Kinetic Properties ◽  
Freshwater Crayfish ◽  
Orconectes Virilis ◽  
Rate Determining Step ◽  
Flow Through ◽  
Glucose 6 Phosphate Dehydrogenase

Glucose-6-phosphate dehydrogenase (G6PDH), the enzyme which catalyzes the rate determining step of the pentose phosphate pathway (PPP), controls the production of nucleotide precursor molecules (R5P) and powerful reducing molecules (NADPH) that support multiple biosynthetic functions, including antioxidant defense. G6PDH from hepatopancreas of the freshwater crayfish (Orconectes virilis) showed distinct kinetic changes in response to 20 h anoxic exposure. Km values for both substrates decreased significantly in anoxic crayfish; Km NADP+ dropped from 0.015±0.008 mM to 0.012±0.008 mM, and Km G6P decreased from 0.13±0.02 mM to 0.08±0.007 mM. Two lines of evidence indicate that the mechanism involved is reversible phosphorylation. In vitro incubations that stimulated protein kinase or protein phosphatase action mimicked the effects on anoxia on Km values, whereas DEAE-Sephadex chromatography showed the presence of two enzyme forms (low- and high-phosphate) whose proportions changed during anoxia. Incubation studies implicated protein kinase A and G in mediating the anoxia-responsive changes in G6PDH kinetic properties. In addition, the amount of G6PDH protein (measured by immunoblotting) increased by ∼60% in anoxic hepatopancreas. Anoxia-induced phosphorylation of G6PDH could contribute to modifying carbon flow through the PPP under anoxic conditions, potentially maintaining NADPH supply for antioxidant defense during prolonged anoxia-induced hypometabolism.

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