scholarly journals LEAD ION AND PHOSPHATASE HISTOCHEMISTRY I. NONENZYMATIC HYDROLYSIS OF NUCLEOSIDE PHOSPHATES BY LEAD ION

1966 ◽  
Vol 14 (10) ◽  
pp. 698-701 ◽  
Author(s):  
ALAN S. ROSENTHAL ◽  
HAROLD L. MOSES ◽  
DAVID L. BEAVER ◽  
SHIRLEY S. SCHUFFMAN
Keyword(s):  
Adenosine Triphosphate ◽  
Atp Hydrolysis ◽  
Linear Increase ◽  
Catalytic Action ◽  
Lead Salt ◽  
Histochemical Localization ◽  
Lead Ion ◽  
High Concentrations ◽  
Rate Limiting ◽  
Hydrolysis Of

A previously undescribed catalytic action of lead ion on the nonenzymatic hydrolysis of nucleoside phosphates has been demonstrated. Lead ion (3.6 mM) hydrolyzed adenosine triphosphate (ATP) at pH 7.2 and 37°C. The presence of magnesium and imidazole was stimulatory. The rate appeared to increase with temperature from 25-60°C. The reaction was inhibited by ethylenediaminetetraacetate. Other nucleoside phosphates were hydrolyzed, some less rapidly than ATP. Adenosine triphosphate in the presence of a rate-limiting amount of lead acted as an inhibitor at high concentrations. With a rate-limiting concentration of ATP (0.72 mM), increasing concentrations of lead ion above 0.36 mM catalyzed a linear increase in ATP hydrolysis. It is suggested that this reaction may be a source of artifact in the lead salt method for the histochemical localization of nucleoside phosphatases.

scholarly journals LEAD ION AND PHOSPHATASE HISTOCHEMISTRY II. EFFECT OF ADENOSINE TRIPHOSPHATE HYDROLYSIS BY LEAD ION ON THE HISTOCHEMICAL LOCALIZATION OF ADENOSINE TRIPHOSPHATASE ACTIVITY

1966 ◽  
Vol 14 (10) ◽  
pp. 702-710 ◽  
Author(s):  
HAROLD L. MOSES ◽  
ALAN S. ROSENTHAL ◽  
DAVID L. BEAVER ◽  
SHIRLEY S. SCHUFFMAN
Keyword(s):  
Plasma Membrane ◽  
Atpase Activity ◽  
Adenosine Triphosphatase ◽  
Lead Nitrate ◽  
Histochemical Localization ◽  
Lead Ion ◽  
Membrane Localization ◽  
Fixed Tissue ◽  
Plasma Membrane Localization ◽  
Hydrolysis Of

The lead method of Wachstein and Meisel for the histochemical localization of adenosine triphosphatase (ATPase) involves the incubation of sections of fixed tissue in reaction mixtures containing ATP, lead nitrate, magnesium sulfate and a Tris-maleate buffer, pH 7.2. Both fixation and the presence of lead ion were shown to inhibit tissue ATPase activity markedly and to inactivate the sodium- plus potassium-dependent membrane ATPase. In addition, recent studies have demonstrated that lead ion, in the concentration used in the Wachstein-Meisel system, will catalyze the hydrolysis of ATP. Studies on the effect of this nonenzymatic reaction on the histochemical localization of ATPases demonstrated that plasma membrane localization occurred only with lead and ATP concentrations which gave significant nonenzymatic hydrolysis of ATP by lead. In addition, nuclear and mitochondrial localization without accompanying plasma membrane localization could be obtained in formalin-fixed tissue with decreased concentrations of lead or with increased concentrations of ATP in the reaction mixture. The amount of lead-catalyzed hydrolysis was in the same order of magnitude as fixed tissue ATPase activity and could quantitatively account for the amount of phosphate needed to give recognizable localization of lead salt deposits in sections of fixed tissue.

THE HYDROLYSIS OF ADENOSINE TRIPHOSPHATE BY BRAIN SUSPENSIONS

1954 ◽  
Vol 32 (1) ◽  
pp. 471-483 ◽  
Author(s):  
Hanna M. Pappius ◽  
K. A. C. Elliott
Keyword(s):  
Atpase Activity ◽  
Adenosine Triphosphate ◽  
Atp Hydrolysis ◽  
Standard Procedure ◽  
High Energy ◽  
Unit Weight ◽  
Bicarbonate Buffer ◽  
Low Magnesium ◽  
Optimum Ph ◽  
Hydrolysis Of

Adenosine triphosphate (ATP) hydrolysis by unfractionated brain suspensions has been measured manometrically and chemically in bicarbonate buffer. Both magnesium and, less strongly, calcium accelerate ATP hydrolysis by brain suspensions. The effectiveness of low magnesium or calcium concentrations is decreased by relatively high ATP concentrations. The optimum pH for phosphate liberation is about 8. The ratio of carbon dioxide evolved to inorganic phosphate liberated depends on the pH. Evidence is given that the suspensions contain a Mg-activated ATPase which is strongly inhibited by calcium, a Ca-activated ATPase, and a Mg-activated PPase which is strongly inhibited by calcium but is different from the Mg-ATPase. These enzymes were not obtained in "latent" form nor activated by glutathione. Ethylenediamine tetraacetate can inhibit Ca-ATPase completely but is less effective on the Mg-ATPase and can release the latter from calcium inhibition. Other inhibitors have been tested.The ATPase activity of cerebral cortex of mouse, rat, cat, beef, and man has been measured by a standard procedure. The activity per unit weight decreases with increasing size of the animal parallel to the decrease in the oxygen uptake rate. Calculations show that the ATPase activity is high enough to release all high energy phosphate which could be produced by esterification coupled with respiration.

Synthesis and hydrolysis of ATP by the mitochondrial ATP synthase

1988 ◽  
Vol 66 (7) ◽  
pp. 677-682 ◽  
Author(s):  
M. Tuena de Gômez-Puyou ◽  
Orlando B. Martins ◽  
A. Gômez-Puyou
Keyword(s):  
Atp Synthase ◽  
Atp Hydrolysis ◽  
Atp Synthesis ◽  
Control Synthesis ◽  
Inhibitor Protein ◽  
Atpase Inhibitor ◽  
Mitochondrial Atp Synthase ◽  
High Concentrations ◽  
Hydrolysis Of

A brief summary of the factors that control synthesis and hydrolysis of ATP by the mitochondrial H+-ATP synthase is made. Particular emphasis is placed on the role of the natural ATPase inhibitor protein. It is clear from the existing data obtained with a number of agents that there is no correlation between variations of the rate of ATP hydrolysis and ATP synthesis as driven by respiration. The mechanism by which each condition differentially affects the two activities is not entirely known. For the case of the natural ATPase inhibitor protein, it appears that the protein controls the kinetics of the enzyme. This control seems essential for achieving maximal accumulation of ATP during electron transport in systems that contain relatively high concentrations of ATP.

THE HYDROLYSIS OF ADENOSINE TRIPHOSPHATE BY BRAIN SUSPENSIONS

1954 ◽  
Vol 32 (5) ◽  
pp. 471-483 ◽  
Author(s):  
Hanna M. Pappius ◽  
K. A. C. Elliott
Keyword(s):  
Atpase Activity ◽  
Adenosine Triphosphate ◽  
Atp Hydrolysis ◽  
Standard Procedure ◽  
High Energy ◽  
Unit Weight ◽  
Bicarbonate Buffer ◽  
Low Magnesium ◽  
Optimum Ph ◽  
Hydrolysis Of

Adenosine triphosphate (ATP) hydrolysis by unfractionated brain suspensions has been measured manometrically and chemically in bicarbonate buffer. Both magnesium and, less strongly, calcium accelerate ATP hydrolysis by brain suspensions. The effectiveness of low magnesium or calcium concentrations is decreased by relatively high ATP concentrations. The optimum pH for phosphate liberation is about 8. The ratio of carbon dioxide evolved to inorganic phosphate liberated depends on the pH. Evidence is given that the suspensions contain a Mg-activated ATPase which is strongly inhibited by calcium, a Ca-activated ATPase, and a Mg-activated PPase which is strongly inhibited by calcium but is different from the Mg-ATPase. These enzymes were not obtained in "latent" form nor activated by glutathione. Ethylenediamine tetraacetate can inhibit Ca-ATPase completely but is less effective on the Mg-ATPase and can release the latter from calcium inhibition. Other inhibitors have been tested.The ATPase activity of cerebral cortex of mouse, rat, cat, beef, and man has been measured by a standard procedure. The activity per unit weight decreases with increasing size of the animal parallel to the decrease in the oxygen uptake rate. Calculations show that the ATPase activity is high enough to release all high energy phosphate which could be produced by esterification coupled with respiration.

Properties Of The Plasma Membrane Atpases Of The Halophilic Archaebacteria Haloferax Mediterranei And Haloferax Volcanii

1992 ◽  
Vol 47 (11-12) ◽  
pp. 835-844 ◽  
Author(s):  
Michaela Dane ◽  
Kerstin Steinert ◽  
Kordula Esser ◽  
Susanne Bickel-Sandkötter ◽  
Francisco Rodriguez-Valera
Keyword(s):  
Atp Hydrolysis ◽  
Ph Value ◽  
Cross Reactivity ◽  
Methanosarcina Barkeri ◽  
Haloferax Volcanii ◽  
Haloferax Mediterranei ◽  
Atpase Subunits ◽  
Halophilic Archaebacteria ◽  
High Concentrations ◽  
Hydrolysis Of

Both, Haloferax mediterranei and Haloferax volcanii membranes contain ATPases which are capable of hydrolyzing ATP in presence of Mg2+ or Mn2+. The ATPases require high concentrations of NaCl, a pH value of 9, and high temperatures up to 60 °C. Free manganese ions inhibited the enzyme activity of either ATPase. The ATPases of Hf. mediterranei and Hf. volcanii, respectively, show different sensitivities to inhibitors of ATP hydrolysis. ATP hydrolysis of isolated Hf. mediterranei ATPase was inhibited by NaN3, which was reported to be specific for F-ATPases, by nitrate and N-ethylmaleimide (NEM), which are specific inhibitors of V-ATPases. ATP hydrolysis of Haloferax mediterranei membranes was not inhibited by DCCD , but [14C]DCCD was bound to a 14 kDa peptide of the isolated, partially purified enzyme. Furthermore, the ATPase was inactivated by preincubation with 7-chloro-4-nitrobenzofurazan (NBD-Cl). The ATPase activity of Hf. volcanii membranes was inhibited by NEM but not by nitrate and NaN3. SDS gel electrophoresis of the partially purified enzyme of Haloferax mediterranei showed putative ATPase subunits of 53.5, 49, 42, 22, 21, 14, 12, and 7.5 kDa. Immunoblots showed cross reactivity between a 53 kDa peptide and anti-β (chloroplast F1), as well as between 53, 50 and 47 kDa peptides and an ATPase antibody of Methanosarcina barkeri. The results will be discussed in context with the placement of the archaebacterial ATPases (A-ATPases) between F- and V-ATPases

scholarly journals A HISTOCHEMICAL STUDY OF ADENOSINE TRIPHOSPHATASE IN THE TOAD (BUFO SPINULOSUS) GASTRIC MUCOSA

1970 ◽  
Vol 18 (5) ◽  
pp. 340-353 ◽  
Author(s):  
CECILIA KOENIG S. ◽  
JUAN D. VIAL C.
Keyword(s):  
Gastric Mucosa ◽  
Atpase Activity ◽  
Adenosine Triphosphatase ◽  
Atp Hydrolysis ◽  
Lead Ion ◽  
Outer Side ◽  
Reaction Products ◽  
Fresh Tissue ◽  
Toad Bufo ◽  
Hydrolysis Of

Adenosine triphosphatase (ATPase) activity was studied by histochemical methods in the gastric mucosa of Bufo spinulosus. Two types of activity were established. One is activated by Mg++, and is localized mainly at the intercellular boundaries and the basal zone of the oxyntic-peptic cells; the reaction products are found only on the outer side of the cells. The other is activated by HCO3– and is mainly localized at the microvilli at the apical zone of the oxyntic-peptic cells. The intensity and/or distribution of the reactions are influenced by histamine stimulation. Control experiments demonstrated that: the microsomal fraction of gastric mucosa contained a Mg++-requiring ATPase activity which was enhanced by addition of HCO3–; 25% of the ATPase activity of fresh tissue was maintained after fixation and incubation in presence of lead ion; the medium employed in the histochemical studies did not enhance the lead-catalyzed, nonenzymatic hydrolysis of ATP by more than 20% when compared with spontaneous ATP hydrolysis; and incubation in media with different ATP-Pb ratios did not significantly alter the location of the staining.

scholarly journals Engineering of Streptoalloteichus tenebrarius 2444 for Sustainable Production of Tobramycin

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4343
Author(s):  
Lena Mitousis ◽  
Hannes Maier ◽  
Luka Martinovic ◽  
Andreas Kulik ◽  
Sigrid Stockert ◽  
...  
Keyword(s):  
Aminoglycoside Antibiotic ◽  
Biosynthetic Gene Cluster ◽  
Genetically Engineered ◽  
Sustainable Production ◽  
Biosynthetic Gene ◽  
Strain Development ◽  
Antibiotic Agent ◽  
Phenotypic Stability ◽  
High Concentrations ◽  
Hydrolysis Of

Tobramycin is a broad-spectrum aminoglycoside antibiotic agent. The compound is obtained from the base-catalyzed hydrolysis of carbamoyltobramycin (CTB), which is naturally produced by the actinomycete Streptoalloteichus tenebrarius. However, the strain uses the same precursors to synthesize several structurally related aminoglycosides. Consequently, the production yields of tobramycin are low, and the compound’s purification is very challenging, costly, and time-consuming. In this study, the production of the main undesired product, apramycin, in the industrial isolate Streptoalloteichus tenebrarius 2444 was decreased by applying the fermentation media M10 and M11, which contained high concentrations of starch and dextrin. Furthermore, the strain was genetically engineered by the inactivation of the aprK gene (∆aprK), resulting in the abolishment of apramycin biosynthesis. In the next step of strain development, an additional copy of the tobramycin biosynthetic gene cluster (BGC) was introduced into the ∆aprK mutant. Fermentation by the engineered strain (∆aprK_1-17L) in M11 medium resulted in a 3- to 4-fold higher production than fermentation by the precursor strain (∆aprK). The phenotypic stability of the mutant without selection pressure was validated. The use of the engineered S. tenebrarius 2444 facilitates a step-saving, efficient, and, thus, more sustainable production of the valuable compound tobramycin on an industrial scale.

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