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  • 1
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 27 (1985), S. 232-237 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Firefly luciferase from Photinus pyralis has been covalently bound to a collagen strip via an acylazide activation process. Immobilization performed in the presence of both substrates ATP and luciferin allows to increase the activity retained on the strip. The best activity exhibited by immobilized luciferase was obtained in a 0.05M Tris-acetate buffer, pH 7.75. The pH optimum and the activation energy of luciferase have been found unchanged after immobilization. In the chosen stirring conditions, no diffusional limitations of substrates appear. ATP measurements can be performed with collagen-bound luciferase in the range 1.10-11 M-3.10-6 M. It was possible to store the strips at 4°C in a dehydrated form; then, the bound enzyme retains 20% of its initial activity after eight months. Human blood ATP was measured with this collagen-bound luciferase and the results were found in good agreement with those obtained by soluble luciferase.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 28 (1986), S. 1154-1158 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The kinetic properties of collagen-bound firefly luciferase have been investigated. Under definite hydrodynamic conditions with low agitation in the reaction medium, the observed behavior is modified compared to the enzyme free in solution: reducing the stirring rate decreases the observed enzymatic activity. But diffusional resistances alone cannot account for these atypical kinetics though mass transfer may certainly play an important role during the transient state of the bioluminescent reaction. After immobilization, the time necessary to reach the steady state increased from 300 ms to 3 min and the two substrates, luciferin and ATP, behave differently with respect to the enzyme: The nature of the saturating substrate first in contact with the bound enzyme is not indifferent suggesting that immobilization can reveal behaviors or mechanisms which are not visualized with the free enzyme.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Biotechnology letters 8 (1986), S. 305-310 
    ISSN: 1573-6776
    Source: Springer Online Journal Archives 1860-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary Taking into account substrate diffusion limitations, computer simulation profiles of product distribution on both sides of a porous enzymic membrane are presented. In compartmentalized enzyme membrane systems like biosensors, the geometry of the system, membrane characteristics and hydrodynamic conditions play a prominent role in the product distribution relative to the substrate diffusional limitations.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Bioluminescence and Chemiluminescence 4 (1989), S. 543-550 
    ISSN: 0884-3996
    Keywords: Fibre-optic ; biosensor ; bioluminescence ; chemiluminescence ; immobilized enzymes ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: The potential of immobilized enzyme membranes in biosensors has been explored in our group for several years. Although part of our work has been mainly devoted to electrochemical transducers and oxidases for the design of enzyme electrodes, the demand for ultrasensitive and highly selective sensors led us to consider the use of luminescent enzyme systems associated to optical transduction. When considering the need for operational and reliable biosensors in biotechnology, immobilization and stability of the sensing element still remain, in most cases, an unavoidable problem. We recently proposed a very fast and reliable procedure for preparing enzymatic membranes from Pall (Biodyne Immunoaffinity membranes) supplied in a pre-activated form. Both the firefly and bacterial systems as well as peroxidase for the chemiluminescent determination of various analytes, could be bound to such a support.Based on this approach, a fibre-optic sensor with immobilized enzymes has been designed which permits bio- or chemiluminescent analysis of ATP, NADH or H2O2 respectively. With the NADH-based system, other analytes could be detected using coupled dehydrogenases. This device appears very promising and includes the convenience of both the luminescence sensitivity as well as the handling of the biosensor design.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Bioluminescence and Chemiluminescence 5 (1990), S. 57-63 
    ISSN: 0884-3996
    Keywords: Fibre-optic ; biosensor ; bacterial bioluminescence ; immobilized enzymes ; NADH-based microassays ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: We have investigated highly selective and ultrasensitive biosensors based on luminescent enzyme systems linked to optical transducers. A fibre-optic sensor with immobilized enzymes was designed; the solid-phase bioreagent was maintained in close contact with the tip of a glass fibre bundle connected to the photomultiplier tube of a luminometer. A bacterial luminescence fibre-optic sensor was used for the microdetermination of NADH. Various NAD(P)-dependent enzymes, sorbitol dehydrogenase, alcohol dehydrogenase and malate dehydrogenase, were co-immobilized on preactivated polyamide membranes with the bacterial system and used for the microdetermination of sorbitol, ethanol and oxaloacetate at the nanomolar level with a good precision.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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