Photo-enhanced hydrolysis of bis(4-nitrophenyl) phosphate using Cu(ii) bipyridine-capped plasmonic nanoparticles

RSC Advances ◽  
2016 ◽  
Vol 6 (47) ◽  
pp. 41618-41621 ◽  
Author(s):  
Scott A. Trammell ◽  
Rafaela Nita ◽  
Brett Martin ◽  
Martin H. Moore ◽  
Jake Fontana ◽  
...  
Keyword(s):  
Laser Irradiation ◽  
Fold Increase ◽  
Green Laser ◽  
Plasmonic Nanoparticles ◽  
Nitrophenyl Phosphate ◽  
Hydrolysis Of ◽  
Bnpp Hydrolysis

A 1000-fold increase in the rate of BNPP hydrolysis occurs under green laser irradiation of a copper(ii) complex on gold.

Preparation of a new metallomicelle catalyst for the hydrolysis of bis(4-nitrophenyl) phosphate

2013 ◽  
Vol 67 (4) ◽  
Author(s):  
Jia-Qing Xie ◽  
Ci Li ◽  
Min Wang ◽  
Bing-Ying Jiang
Keyword(s):  
Reaction Rate ◽  
Active Species ◽  
Local Concentration ◽  
Catalytic Hydrolysis ◽  
Catalytic Function ◽  
Nitrophenyl Phosphate ◽  
Spontaneous Hydrolysis ◽  
Lauryl Ether ◽  
Hydrolysis Of ◽  
Bnpp Hydrolysis

AbstractA new metallomicellar system containing cerium(III), a macrocylic polyamine ligand, and the nonionic surfactant Brij35(polyoxyethylene(23) lauryl ether) was prepared and used as a catalyst in the hydrolysis of bis(4-nitrophenyl) phosphate (BNPP). Catalytic rate of the BNPP hydrolysis was measured kinetically using the UV-VIS spectrophotometric method. The results indicate that the metallomicellar system has relatively high stability and excellent catalytic function in the BNPP hydrolysis; also, the reaction rate of the BNPP catalytic hydrolysis increased by a factor of ca. 1 × 1010 compared to the BNPP spontaneous hydrolysis due to the catalytic effect of the active species and the local concentration effect of the micelles in the metallomicellar system. Experimental results also showed that the mono-hydroxy complex containing the macrocyclic polyamine ligand and cerium(III) is the real active species in the BNPP catalytic hydrolysis, and that the micelles provide a useful catalytic environment for the reaction. On basis of the research results, the reaction mechanism of BNPP catalytic hydrolysis has been proposed.

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

1975 ◽  
Vol 23 (11) ◽  
pp. 828-839 ◽  
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.

Catalytic Hydrolysis of 4-Nitrophenyl Phosphate by Lanthanum(III)-Hectorite

Langmuir ◽  
2003 ◽  
Vol 19 (6) ◽  
pp. 2188-2192 ◽  
Author(s):  
Steven T. Frey ◽  
Benjamin M. Hutchins ◽  
Brian J. Anderson ◽  
Teresa K. Schreiber ◽  
Michael E. Hagerman
Keyword(s):  
Catalytic Hydrolysis ◽  
Nitrophenyl Phosphate ◽  
Hydrolysis Of

scholarly journals Phosphatase synthesis in Klebsiella (Aerobacter) aerogenes growing in continuous culture

1972 ◽  
Vol 127 (1) ◽  
pp. 87-96 ◽  
Author(s):  
P. G. Bolton ◽  
A. C. R. Dean
Keyword(s):  
Alkaline Phosphatase ◽  
Acid Phosphatase ◽  
Continuous Culture ◽  
Activity Profile ◽  
Glucose Effect ◽  
Ph Values ◽  
Nitrophenyl Phosphate ◽  
Wide Range ◽  
Rate Of Hydrolysis ◽  
Hydrolysis Of

1. Phosphatase synthesis was studied in Klebsiella aerogenes grown in a wide range of continuous-culture systems. 2. Maximum acid phosphatase synthesis was associated with nutrient-limited, particularly carbohydrate-limited, growth at a relatively low rate, glucose-limited cells exhibiting the highest activity. Compared with glucose as the carbon-limiting growth material, other sugars not only altered the activity but also changed the pH–activity profile of the enzyme(s). 3. The affinity of the acid phosphatase in glucose-limited cells towards p-nitrophenyl phosphate (Km 0.25–0.43mm) was similar to that of staphylococcal acid phosphatase but was ten times greater than that of the Escherichia coli enzyme. 4. PO43−-limitation derepressed alkaline phosphatase synthesis but the amounts of activity were largely independent of the carbon source used for growth. 5. The enzymes were further differentiated by the effect of adding inhibitors (F−, PO43−) and sugars to the reaction mixture during the assays. In particular, it was shown that adding glucose, but not other sugars, stimulated the rate of hydrolysis of p-nitrophenyl phosphate by the acid phosphatase in carbohydrate-limited cells at low pH values (<4.6) but inhibited it at high pH values (>4.6). Alkaline phosphatase activity was unaffected. 6. The function of phosphatases in general is discussed and possible mechanisms for the glucose effect are outlined.

Pressure Effects on the Interactions of the Sarcoplasmic Reticulum Calcium Transport Enzyme with Calcium and para-Nitrophenyl Phosphate

1987 ◽  
Vol 42 (5) ◽  
pp. 641-652 ◽  
Author(s):  
Wilhelm Hasselbach ◽  
Lore Stephan
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Calcium Transport ◽  
Activation Volume ◽  
Reaction Scheme ◽  
Pressure Effects ◽  
Calcium Dependent ◽  
Nitrophenyl Phosphate ◽  
Hydrolysis Of ◽  
Sarcoplasmic Reticulum Calcium ◽  
Effect Of Hydrostatic Pressure

The effect of hydrostatic pressure on calcium dependent p-nitrophenyl phosphate hydrolysis of the sarcoplasmic reticulum calcium transport enzyme has been investigated at different degree of enzyme saturation by calcium and Mg-p-nitrophenyl phosphate to distinguish between activation and binding volumes. The enzyme saturated by both ligands displays a significant dependence of the activation volume on pressure, rising from 20 ml/mol at atmospheric pressure (0.1 MPa) to 80 ml/mol at 100 MPa. At subsaturating concentration of Mg-p-nitrophenyl phosphate an activation volume of 35 ml/mol prevails between 0.1 and 40 MPa. At subsaturating concentration of calcium the activation volume approximates 80 ml/mol in the same pressure range. The binding volume for both substrates is likewise pressure dependent falling from 20 ml/mol to 0 ml/mol for Mg-p-nitrophenyl phosphate and rising from 67 ml/mol to 155 ml/mol for calcium. The pressure dependence of activation and binding volumes is analysed on account of a simplified reaction scheme yielding activation volumes and rate constants for individual reaction steps.

New insights into lactase and glycosylceramidase activities of rat lactase-phlorizin hydrolase

1989 ◽  
Vol 257 (4) ◽  
pp. G616-G623 ◽  
Author(s):  
H. A. Buller ◽  
A. G. Van Wassenaer ◽  
S. Raghavan ◽  
R. K. Montgomery ◽  
M. A. Sybicki ◽  
...  
Keyword(s):  
Active Sites ◽  
Specific Activity ◽  
Fold Increase ◽  
Developmental Pattern ◽  
Lactose Hydrolysis ◽  
Adult Males ◽  
Lactase Activity ◽  
Developmental Patterns ◽  
Catalytic Sites ◽  
Hydrolysis Of

Lactase-phlorizin hydrolase, a small intestinal disaccharidase, has been considered mainly an enzyme important only for the hydrolysis of lactose. After weaning in most mammals lactase-specific activity falls markedly, and, functionally, adult mammals are considered to be lactase deficient. However, the persistence of low levels of lactase activity in adulthood has never been explained. In addition, it has been suggested that lactase-phlorizin hydrolase is associated with glycosylceramidase activity when the enzyme is prepared by column chromatography, but it is unclear whether this represents copurified activities or two catalytic sites on one peptide. The developmental patterns of lactase-phlorizin hydrolase and other disaccharidases were investigated in homogenates of total rat small intestine; lactase and several glycosylceramidases were measured in immunoprecipitates from these homogenates using a monoclonal antibody. The developmental pattern of total lactase activity showed a steady 2.3-fold increase to adult levels (specific activity decreased eightfold), whereas total phlorizin-hydrolase activity increased 10.7-fold (specific activity decreased threefold). As expected, levels of both total and specific sucrase and maltase activities increased during development. In lactating rats total lactase activity showed a significant increase compared with adult males. The developmental pattern of the enzyme activities for the glycolipid substrates was similar to that found for lactase, and the immunoprecipitated enzyme showed a 40- to 55-fold higher affinity for the glycolipids than for lactose. Galactosyl- and lactosylceramide inhibited lactose hydrolysis by 38%, without a competitive pattern, suggesting two different active sites for lactose and glycolipid hydrolysis, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

A Continuous Spectrophotometric Method for Measuring the Activity of Serum Alkaline Phosphatase

1966 ◽  
Vol 12 (2) ◽  
pp. 70-89 ◽  
Author(s):  
George N Bowers ◽  
Robert B McComb
Keyword(s):  
Alkaline Phosphatase ◽  
Standard Deviation ◽  
Sample Size ◽  
Spectrophotometric Method ◽  
Serum Alkaline Phosphatase ◽  
Serum Alkaline Phosphatase Activity ◽  
Factors Affecting ◽  
Nitrophenyl Phosphate ◽  
Relative Standard ◽  
Hydrolysis Of

Abstract A continuous spectrophotometric method for measuring serum alkaline phosphatase activity is described. The effects of temperature, pH, substrate concentration, type and molarity of the buffer, sample size, cofactors, and inhibitors on the enzymatic hydrolysis of p-nitrophenyl phosphate were studied. The optimal conditions for assay of serum alkaline phosphatase at 30° were found to be 0.75 M 2-amino-2-methyl-1-propanol buffer, pH30° 10.15, 4 mmole substrate, and 100 µl. or less sample size. Studies of the factors affecting analytical precision-i.e., control of reaction temperature, of reagent manufacture, and of standardization-are discussed. The precision of this method was 2.3% (relative standard deviation) on 10 within day replicates and 5.0% on day-to-day replicates spread over a 5-week period. The range of activity for 258 apparently healthy adult blood donors was 6-110 mU./ml. (International milliunits per milliliter), with a mean of 49 and a standard deviation of 14.

Influence of C-ANF receptor and neutral endopeptidase on pharmacokinetics of ANF in rats

1991 ◽  
Vol 260 (1) ◽  
pp. R208-R216 ◽  
Author(s):  
P. J. Chiu ◽  
G. Tetzloff ◽  
M. T. Romano ◽  
C. J. Foster ◽  
E. J. Sybertz
Keyword(s):  
High Performance ◽  
Fold Increase ◽  
Neutral Endopeptidase ◽  
Volume Of Distribution ◽  
Fourfold Increase ◽  
Control Value ◽  
Enzymatic Pathways ◽  
Hydrolysis Of

The role of C-atrial natriuretic factor (ANF) receptors and neutral endopeptidase (NEP) in the pharmacokinetics and hydrolysis of 125I-labeled ANF was evaluated in rats by using C-ANF and SCH 39370 to block the nonenzymatic and enzymatic pathways, respectively. After a bolus injection of 125I-ANF, the resulting area under the plasma concentration curve (AUC) with C-ANF treatment was seven times the control value with regard to trichloroacetic acid-precipitable (TCA-ppt) radioactivity (intact ANF). SCH 39370 tended to increase AUC, but the changes were not significant. Nevertheless, SCH 39370 suppressed the appearance of TCA-soluble radioactivity (hydrolytic products), indicating that in vivo inhibition of ANF degradation had occurred. SCH 39370 plus C-ANF produced a 15-fold increase in AUC for TCA-ppt radioactivity and a reduction in plasma TCA-soluble radioactivity. High-performance liquid chromatography (HPLC) analysis confirmed that combination treatment increased intact ANF and reduced hydrolytic products in the plasma. SCH 39370 reduced clearance (C) without altering volume of distribution in steady state (Vss) and half-life (t1/2). C-ANF decreased both C and Vss leading to a fourfold increase in t1/2, which was further prolonged by SCH 39370 (7.5 times control). Bilateral nephrectomy caused a proportionally similar decrease in Vss and C without changing t1/2, suggesting significant extrarenal metabolism of ANF. SCH 39370 systemically inhibits ANF hydrolysis; the resulting increase in ANF, however, is masked by the great capacity of ANF clearance receptors but can be revealed with excess C-ANF, suggesting that the plasma ANF concentrations are determined by the interplay of the C-ANF receptor and NEP systems.

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