Carboxylic Groups as Cofactors in the Lanthanide-Catalyzed Hydrolysis of Phosphate Esters. Stabilities of Europium(III) Complexes with Aza-benzo-15-crown-5 Ether Derivatives and Their Catalytic Activity vs Bis(p-nitrophenyl)phosphate and DNA

The activities of N-acetylneuraminate 9-phosphate synthase and N-acetylneuraminate 9-phosphatase, the two enzymes involved in the final steps of the biosynthetic pathway of N-acetylneuraminic acid, were measured with the substrates N-acetyl[14C]mannosamine 6-phosphate and N-acetyl[14C]neuraminic acid 9-phosphate respectively. Subcellular localization studies in rat liver indicated that both enzymes are localized in the cytosolic fraction after homogenization in sucrose medium. To test the possibility of misinterpretation due to the hydrolysis of N-acetylneuraminic acid 9-phosphate by non-specific phosphatases, the hydrolysis of various phosphate esters by the cytosolic fraction was tested. Only p-nitrophenyl phosphate was hydrolysed; however, competition studies with N-acetylneuraminic acid 9-phosphate and p-nitrophenyl phosphate indicated that two different enzymes were involved and that no competition existed between the two substrates. In various other rat tissues N-acetylneuraminate-9-phosphate synthase and N-acetylneuraminate 9-phosphatase activities were detected, suggesting that N-acetylmannosamine 6-phosphate is a general precursor for N-acetylneuraminic acid biosynthesis in all the tissues studied.

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Acid phosphatase activity demonstrated by intact Angiostrongylus cantonensis with special reference to its function

Parasitology ◽

10.1017/s0031182000053816 ◽

1979 ◽

Vol 79 (3) ◽

pp. 417-423 ◽

Cited By ~ 3

Author(s):

Jun Maki ◽

Toshio Yanagisawa

Keyword(s):

Acid Phosphatase ◽

External Medium ◽

Reciprocal Inhibition ◽

Angiostrongylus Cantonensis ◽

Phosphate Esters ◽

Glucose Phosphate ◽

Nitrophenyl Phosphate ◽

Inhibition Studies ◽

Hydrolysis Of

SUMMARYIntact Angiostrongylus cantonensis is able to hydrolyse glucose-phosphate esters, mononucleotides and p-nitrophenyl phosphate as well as β-glycerophosphate in vitro. Reciprocal inhibition studies suggest that the hydrolysis of such substrates is due to a non-specific phosphomonoesterase. Molybdate ions, which exert no effect on either the uptake of glucose or the production of lactate, inhibit the hydrolysis of glucose-1- phosphate in the external medium and simultaneously lower the production of lactate by the intact worms in vitro.

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ChemInform Abstract: HYDROLYSIS OF PHOSPHATE ESTERS BOUND TO COBALT(III). KINETICS AND MECHANISM OF INTRAMOLECULAR ATTACK OF HYDROXIDE ON COORDINATED 4-NITROPHENYL PHOSPHATE

Chemischer Informationsdienst ◽

10.1002/chin.198412297 ◽

1984 ◽

Vol 15 (12) ◽

Author(s):

D. R. JONES ◽

L. F. LINDOY ◽

A. M. SARGESON

Keyword(s):

Kinetics And Mechanism ◽

Phosphate Esters ◽

Nitrophenyl Phosphate ◽

Hydrolysis Of

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Hydrolysis of phosphate esters bound to cobalt(III). Kinetics and mechanism of intramolecular attack of hydroxide on coordinated 4-nitrophenyl phosphate

Journal of the American Chemical Society ◽

10.1021/ja00363a021 ◽

1983 ◽

Vol 105 (25) ◽

pp. 7327-7336 ◽

Cited By ~ 70

Author(s):

David R. Jones ◽

Leonard F. Lindoy ◽

Alan M. Sargeson

Keyword(s):

Kinetics And Mechanism ◽

Phosphate Esters ◽

Nitrophenyl Phosphate ◽

Hydrolysis Of

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The presence of a Zn2+-dependent acid p-nitrophenyl phosphatase in bovine liver. Isolation and some properties

Biochemical Journal ◽

10.1042/bj2350265 ◽

1986 ◽

Vol 235 (1) ◽

pp. 265-268 ◽

Cited By ~ 12

Author(s):

F Panara

Keyword(s):

Catalytic Activity ◽

Bovine Liver ◽

Phosphate Esters ◽

Acid Phosphatases ◽

Bivalent Cations ◽

Apparent Homogeneity ◽

Nitrophenyl Phosphate ◽

Mammalian Tissues ◽

Optimum Ph ◽

The Common

The presence of a Zn2+-dependent acid p-nitrophenyl phosphatase (EC 3.1.3.2) in bovine liver was described. The enzyme was purified to apparent homogeneity and migrates as a single band during electrophoresis on polyacrylamide gel. The enzyme requires Zn2+ ions for catalytic activity, other bivalent cations have little or no effect. The enzyme, of Mr 118,000, optimum pH 6-6.2 and pI 7.4-7.5, was inhibited by EDTA, tartrate, adenine and ATP, but not by fluoride. The common phosphate esters are poor substrates for the enzyme, which hydrolyses preferentially p-nitrophenyl phosphate and o-carboxyphenyl phosphate. The Zn2+-dependent acid p-nitrophenyl phosphatase of bovine liver was different from the high-Mr acid phosphatases previously detected in mammalian tissues.

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Immobilized Nanoparticles-Mediated Enzymatic Hydrolysis of Cellulose for Clean Sugar Production: A Novel Approach

Current Nanoscience ◽

10.2174/1573413714666180611081759 ◽

2019 ◽

Vol 15 (3) ◽

pp. 296-303 ◽

Cited By ~ 5

Author(s):

Swapnil Gaikwad ◽

Avinash P. Ingle ◽

Silvio Silverio da Silva ◽

Mahendra Rai

Keyword(s):

Catalytic Activity ◽

Enzymatic Hydrolysis ◽

Immobilized Enzyme ◽

Free Enzyme ◽

Magnetic Nanomaterials ◽

Sugar Production ◽

Cellulase Enzyme ◽

Enzymatic Hydrolysis Of Cellulose ◽

Hydrolysis Of Cellulose ◽

Hydrolysis Of

Background: Enzymatic hydrolysis of cellulose is an expensive approach due to the high cost of an enzyme involved in the process. The goal of the current study was to apply magnetic nanomaterials as a support for immobilization of enzyme, which helps in the repeated use of immobilized enzyme for hydrolysis to make the process cost-effective. In addition, it will also provide stability to enzyme and increase its catalytic activity. Objective: The main aim of the present study is to immobilize cellulase enzyme on Magnetic Nanoparticles (MNPs) in order to enable the enzyme to be re-used for clean sugar production from cellulose. Methods: MNPs were synthesized using chemical precipitation methods and characterized by different techniques. Further, cellulase enzyme was immobilized on MNPs and efficacy of free and immobilized cellulase for hydrolysis of cellulose was evaluated. Results: Enzymatic hydrolysis of cellulose by immobilized enzyme showed enhanced catalytic activity after 48 hours compared to free enzyme. In first cycle of hydrolysis, immobilized enzyme hydrolyzed the cellulose and produced 19.5 ± 0.15 gm/L of glucose after 48 hours. On the contrary, free enzyme produced only 13.7 ± 0.25 gm/L of glucose in 48 hours. Immobilized enzyme maintained its stability and produced 6.15 ± 0.15 and 3.03 ± 0.25 gm/L of glucose in second and third cycle, respectively after 48 hours. Conclusion: This study will be very useful for sugar production because of enzyme binding efficiency and admirable reusability of immobilized enzyme, which leads to the significant increase in production of sugar from cellulosic materials.

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Renal sodium-potassium adenosine triphosphatase. Optical localization and x-ray microanalysis.

Journal of Histochemistry & Cytochemistry ◽

10.1177/23.11.127810 ◽

1975 ◽

Vol 23 (11) ◽

pp. 828-839 ◽

Cited By ~ 28

Author(s):

R Beeuwkes ◽

S Rosen

Keyword(s):

Atpase Activity ◽

Electron Probe ◽

Sequential Analysis ◽

Relative Sensitivity ◽

Initial Reaction ◽

Initial Product ◽

Sodium Potassium ◽

Nitrophenyl Phosphate ◽

Hydrolysis Of ◽

Convoluted Tubules

The distribution of sodium-potassium adenosine triposphatase (Na-K-ATPase) activity in kidney sections has been studied by a method based on the hydrolysis of p-nitrophenyl phosphate in alkaline medium containing dimethyl sulfoxide. The products at each stage in the reaction sequence have been subjected to electron probe microanalysis. The initial product was identified as a mixture of KMgPO4 and Mg(PO4)2, and sequential analysis demonstrated the linearity of conversion of this product to a visible form. In human, rabbit and rat kidneys the distribution of activity was found to be essentially identical, with highest levels located in thick ascending limbs and distal convoluted tubules. The initial reaction was completely potassium dependent and was inhibited by ouabain in concentrations reflecting the relative sensitivity of microsomal Na-K-ATPase in each species. Measurement of initial product phosphorus by means of the electron probe is presented as a practical technique for direct quantitation of Na-K-ATPase activity in identified tubule segments.

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