A Microtiter-Plate Urease Inhibition Assay-Sensitive, Rapid and Cost-Effective Screening for Heavy Metals in Water

Wittekindt, E.; Werner, Marilyn G.; Reinicke, Andreas; Herbert, Allergan; Hansen, P.M.T.

doi:10.1080/09593331708616423

Cited by 26 publications

(11 citation statements)

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“…Urease inhibition was first studied with Hg(II), since it has been reported in the literature as being the most potent inhibitor for the urease enzyme, along with Cu(II) and Ag (I) (Krajewska, 1991;Andres and Narayanaswamy, 1995;Wittekindt et al, 1996). The effect of Hg(II) on the enzyme GLDH was examined in this work in order to check the inhibition this metal can produce on the enzyme.…”

Section: Urease Spectrophotometric Assaymentioning

confidence: 98%

“…Assays based on the inhibition of urease show a high selectivity for the sensitive and effect-based screening of heavy metals (Jung et al, 1995;Wittekindt et al, 1996;Brack et al, 2000). Most urease inhibition assays are based on the measurement of either pH changes (Shi et al, 1997;Kormos and Lengauer, 2000;Krawczyk et al, 2000) or ammonia production (Gil and Piedade, 1992;Soldatkin et al, 2000).…”

Section: Introductionmentioning

confidence: 98%

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Development of urease and glutamic dehydrogenase amperometric assay for heavy metals screening in polluted samples

Rodriguez

Bolbot

Tothill

2004

Biosensors and Bioelectronics

125

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Section: Urease Spectrophotometric Assaymentioning

confidence: 98%

Section: Introductionmentioning

confidence: 98%

Development of urease and glutamic dehydrogenase amperometric assay for heavy metals screening in polluted samples

Rodriguez

Bolbot

Tothill

2004

Biosensors and Bioelectronics

125

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“…Some heavy metals can also inhibit the urease activity by binding to sulfhydryl groups of the active site of urease, forming metal-sulfide equivalents [6]. Since the urease activity may be used to assess the ecological status in soils monitoring programs, some investigations have been made to measure the influence of some organic or inorganic pollutants on urease activity [6][7][8][9][10]. Samborska et al have studied the influence of different oxidation states of chromium(VI, III) on soil urease activity [7].…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…The urease activity is associated mainly with soil organic matter that may denature the entire protein structure [6]. Some heavy metals can also inhibit the urease activity by binding to sulfhydryl groups of the active site of urease, forming metal-sulfide equivalents [6]. Since the urease activity may be used to assess the ecological status in soils monitoring programs, some investigations have been made to measure the influence of some organic or inorganic pollutants on urease activity [6][7][8][9][10].…”

Section: Introductionmentioning

confidence: 99%

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The Interaction of Chromium(VI) with Urease in Solution

Zhang

Wang

2010

Biol Trace Elem Res

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The interaction between K(2)Cr(2)O(7) and urease was investigated using fluorescence, UV-vis absorption, and circular dichroism (CD) spectroscopy. The experimental results showed that the fluorescence quenching of urease by K(2)Cr(2)O(7) was a result of the formation of K(2)Cr(2)O(7)-urease complex. The apparent binding constant K (A) between K(2)Cr(2)O(7) and urease at 295, 302, and 309 K were obtained to be 2.14 × 10(4), 1.96 × 10(4), and 1.92 × 10(4) L mol(-1), respectively. The thermodynamic parameters, ΔH° and ΔS° were estimated to be -5.90 kJ mol(-1), 43.67 J mol(-1) K(-1) according to the Van't Hoff equation. The electrostatic interaction played a major role in stabilizing the complex. The distance r between donor (urease) and acceptor (K(2)Cr(2)O(7)) was 5.08 nm. The effect of K(2)Cr(2)O(7) on the conformation of urease was analyzed using UV-vis absorption, CD, synchronous fluorescence spectroscopy, and three-dimensional fluorescence spectra, the environment around Trp and Tyr residues were altered.

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Enzymatic Kinetic Determinations

Hüttl

2000

Encyclopedia of Analytical Chemistry

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Kinetic methods for analytical applications can be divided into noncatalytic and catalytic methods. Enzyme kinetic determinations are a special type of catalytic methods. Enzymatic reactions are used analytically to determine enzyme activities – for instance in the diagnosis of diseases, substrate concentrations in food industry or medicine and concentrations of effectors – for example in trace analysis. Due to the high selectivity of enzymatic analysis the importance of this method in various fields is growing rapidly. The widest use is observed in clinical chemistry and in food chemistry. This article can only give a general survey of the great potential of enzymatic analysis, with references to more detailed literature. Enzymatic reactions are characterized by some special features, explained after the introduction. The theoretical background for kinetic determination is the comprehension of the principles on enzymatic kinetics. In section 3 the simplest mechanism, outlined by Michaelis and Menten and several transformations of this equation will be described. In this section two kinetic parameters, enzyme activity and the Michaelis constant, will be introduced. Section 4 deals with substances, so called effectors, influencing the rate of an enzymatic reaction. Simple mechanisms of these effectors will be shown. The different methods for determination of substrates, enzymes and effectors, illustrated by many examples, are represented in section 5. While substrate concentrations can be determined using both ways, equilibrium or kinetic methods, the determination of enzymes and effectors can only be performed by kinetic approaches. In the last two sections the application of immobilized enzymes in flow systems and biosensor development will be shown.

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A Microtiter-Plate Urease Inhibition Assay-Sensitive, Rapid and Cost-Effective Screening for Heavy Metals in Water

Cited by 26 publications

References 0 publications

Development of urease and glutamic dehydrogenase amperometric assay for heavy metals screening in polluted samples

Development of urease and glutamic dehydrogenase amperometric assay for heavy metals screening in polluted samples

The Interaction of Chromium(VI) with Urease in Solution

Enzymatic Kinetic Determinations

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