Electrochemical Assay of Plasminogen Activators in Plasma Using Polyion-Sensitive Membrane Electrode Detection

Chang, Li Chien; Meyerhoff, Mark E.; Yang, Victor C.

doi:10.1006/abio.1999.4299

Cited by 11 publications

(8 citation statements)

References 20 publications

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“…Potentiometric sensors based on polymeric membrane polyion-selective electrodes have been successfully used previously to monitor various protease enzyme activities and inhibitors of given enzymes [33–37]. These sensors yield a large, non-equilibrium potentiometric response to protamine and similar polycationic oligopeptides and the magnitude of the observed potential change is related to the chain length and charge density of the polypeptides [38].…”

Section: Introductionmentioning

confidence: 99%

Detection of protease activities by flash chronopotentiometry using a reversible polycation-sensitive polymeric membrane electrode

Gemene

Meyerhoff

2011

Analytical Biochemistry

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A novel electrochemical method, termed flash chronopotentiometry (FCP), is used to develop a rapid and sensitive method to detect protease activities. In this method, an appropriate current pulse is applied across a polycation-selective polymer membrane to induce a strong flux of the polycationic peptides from the sample phase into the organic membrane of the electrode. During this current pulse, the cell potential (EMF) is monitored continuously, and is a function of the polypeptide concentration. The imposed current causes a local depletion of the polypeptide at the sample/membrane interface, which yields a drastic potential change in the observed chronopotentiogram at a characteristic time, called the transition time (τ). For a given magnitude of current, the square root of τ is directly proportional to the concentration of the polypeptide. Proteases cleave polypeptides into smaller fragments that are not favorably extracted into the membrane of the sensor. Therefore, a decrease in the transition time is observed during the proteolysis process. The degree of change in the transition time can be correlated to protease activity. To demonstrate this approach, the activities of trypsin and α-chymotrypsin are detected using protamine and synthetic polycationic oligopeptides that possess specific cleavage sites that are recognized by these proteases.

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Section: Introductionmentioning

confidence: 99%

Detection of protease activities by flash chronopotentiometry using a reversible polycation-sensitive polymeric membrane electrode

Gemene

Meyerhoff

2011

Analytical Biochemistry

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“…Electrochemical method of Protease activity Three separate DNNS-based protamine-sensitive membrane electrodes were used simultaneously to monitor the initial decrease in protamine levels (Chang et al, 1991). Experiments were performed by adding 5 (Sigma, St. Louis, MO) solution to 1 ml of Tris working buffer (50 mM Tris and 120 mM NaCl, pH 7.4) to yield a final concentration of 25 reaching a steady-state/ non-equilibrium (5 min) sample mixture containing MP was added to the solution.…”

Section: Spectrophotometric Methods Of Protease Activitymentioning

confidence: 99%

Bioremediation of Some Agricultural Wastes by Bacillus Thuringiensis for Metalloprotease Production

Rizk

Eldourghamy

Elgamal

2017

Research Journal of Applied Biotechnology

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Agricultural wastes are very rich in nutrients that can be used as complete balanced microbiological media for growing microbes in order to produce valuable commercial products. In this study, a biodegradation process of wheat bran and rice bran wastes was carried out to produce metalloprotease enzyme from B. thuringiensis 1257strain which is considered to be a hyper producer for that enzyme. Metalloprotease was partially purified by ammonium sulfate followed by application on Sephadex G-75 column. Gel filtration step resulted in more than 40 times fold purification of the purified enzyme. The enzyme activity was inhibited by EDTA (almost 80%) at 15 mM concentration. These agro-industrial wastes were used as substrates for economic production of the enzyme from B. thuringiensis compared with some bacterial isolates collected from different sites in Kafr El-Sheikh and Menofiya governorate, Egypt. Optimum temperature for enzyme activity was 40 °C. It also exhibited a broad pH activity range (6-9) with an optimum pH of 8.

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“…Three separate DNNS-based protamine-sensitive membrane electrodes were used simultaneously to monitor the initial decrease in protamine levels (Chang et al, 1999). Experiments were performed by adding 5 l of a 5 mg/ml protamine (Sigma, St. Louis, MO) solution to 1 ml of Tris working buffer (50 mM Tris and 120 mM NaCl, pH 7.4).…”

Section: Electrochemical Assay Of Streptokinasementioning

confidence: 99%

“…3). The two methods are based on detecting the amidolytic activity of plasminlibrated after plasminogen activation by streptokinaseupon synthetic chromogenic substrates (Chang et al, 1999). Although these methods are accurate and reliable, they are expensive and their total reaction time is relatively high.…”

Section: Detection Of Streptokinasementioning

confidence: 99%

In vitro Detection and Optimization of Streptokinase Production by Two Streptococcal Strains in a Relatively Low Cost Growth Medium

2012

Egypt. J. Microbiol.

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HIS STUDY sought to demonstrate the optimization of ……..streptokinase production. Enzyme production was monitored during the growth of both Streptococcus pyogenes and Streptococcus equisimilis in different media. Adjustment of the pH for culture media of S. pyogenes and S. equisimilis, every 12 hr during incubation, significantly increased the enzyme production levels, when both microbes were grown on Strep-base medium. The best carbon source for streptokinase production was glucose of both S. pyogenes and S. equisimilis, while mannitol and sorbitol were found to be less suitable carbon sources. Yeast extract, and casein could be used as the primary source of organic nitrogen for streptokinase production, when the microbes were allowed to grow on Strep-base medium. The highest levels of the enzyme production were obtained with 1.5 % (w/v) tryptone and 1.5 % (w/v) casein for S. equisimilis and S. pyogenes, respectively. Detection of streptokinase produced was by the common casein digestion method and by the more sensitive chromozym substrate digestion method. Moreover, the enzyme was assayed electrochemically using the protamine-sensitive electrode to compare different methods of detection. Results obtained from electrochemical method were very close to that obtained with other methods. These results offer an alternative and reliable method for streptokinase detection during microbial growth. It provides a faster and less expensive technique for streptokinase determination especially when there is a need to detect the enzyme in turbid media.

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Electrochemical Assay of Plasminogen Activators in Plasma Using Polyion-Sensitive Membrane Electrode Detection

Cited by 11 publications

References 20 publications

Detection of protease activities by flash chronopotentiometry using a reversible polycation-sensitive polymeric membrane electrode

Detection of protease activities by flash chronopotentiometry using a reversible polycation-sensitive polymeric membrane electrode

Bioremediation of Some Agricultural Wastes by Bacillus Thuringiensis for Metalloprotease Production

In vitro Detection and Optimization of Streptokinase Production by Two Streptococcal Strains in a Relatively Low Cost Growth Medium

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