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'Immobilized Enzymes' in keywords

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1	Author	E. Horozova, N. Dimcheva, Z. Jordanova	Requires cookie*
	Title	Peroxidase-Like Activity of Catalase Immobilized on Carbon Materials
	Abstract	The immobilization of catalase was carried out from enzyme solutions in acid (pH < 3.5) and alkaline (pH > 1 1) medium on two kinds of soot differing by the average size of the particles. Under these conditions the peroxidase-like activity of immobilized catalase in the oxidation of phenol has been studied. The effect of the initial concentration of the substrate on the rate of the process catalysed by catalase immobilized on the soot of finer-grained structure has been studied. The relationships obtained are described by the equation of Mi-chaelis-M enten. The kinetic parameters (the constant of Michaelis -K m, the maximum reac tion rate -Vmax, the rate constant -k and the activation energy -Ea) of the process were calculated. It was found that catalase absorbed on the soot of larger globular particles does not take part in the peroxidase oxidation of phenol.
	Reference	Z. Naturforsch. 53c, 863—8 (1998); received March 3/May 15 1998
	Published	1998
	Keywords	Catalase, Immobilized Enzyme, Carbon Materials, Peroxidase-Like Activity
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	TEI-XML for	default:Reihe_C/53/ZNC-1998-53c-0863.pdf
	Identifier	ZNC-1998-53c-0863
	Volume	53

2	Author	E. Horozova, N. Dimcheva, Z. Jordanova	Requires cookie*
	Title	Enzymatic and Electrochemical Reactions of Xanthine Oxidase Immobilized on Carbon Materials
	Abstract	A n optimum way o f immobilizing xanthine oxidase on graphite was found where a redox transformation of the enzyme was observed. The nature o f the redox maxima was hypothe sized on the basis of the dependence of the half-wave potential (E p/2) on the pH of the solution. The enzymatic activity of xanthine oxidase adsorbed on two kinds o f soot was studied by the oxidation o f xanthine. The kinetic and activation parameters of the enzyme reaction were determined.
	Reference	Z. Naturforsch. 52c, 159—164 (1997); received November ll/
	Published	1997
	Keywords	Xanthine Oxidase, Immobilized Enzyme, Carbon Materials, Electrochemical and Catalytic Activity
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	TEI-XML for	default:Reihe_C/52/ZNC-1997-52c-0159.pdf
	Identifier	ZNC-1997-52c-0159
	Volume	52

3	Author	E. Horozova, N. Dimcheva, Z. Jordanova	Requires cookie*
	Title	Adsorption, Catalytic and Electrochemical Activity o f Catalase Immobilized on Carbon Materials
	Abstract	The adsorption of catalase on two types of soot differing in their structure has been charac terized. The adsorption of this enzyme obeys the Tyomkin adsorption isotherm. It has been established that the catalase immobilized on soot and graphite takes part in the electrochem i cal oxidation of phenol. The enzyme activity of catalase immobilized on both types of soot was studied on the decomposition of hydrogen peroxide. The kinetic and activation param e ters of the processes studied have been determined.
	Reference	Z. Naturforsch. 52c, 639—644 (1997); received May 5/July 3 1997
	Published	1997
	Keywords	Catalase, Immobilized Enzyme, Carbon Materials, Electrochemical and Biocatalytic Activity
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	TEI-XML for	default:Reihe_C/52/ZNC-1997-52c-0639.pdf
	Identifier	ZNC-1997-52c-0639
	Volume	52

4	Author	Elena Horozova, Nina Dimcheva, Zinaida Jordanova	Requires cookie*
	Title	Catalytic Decomposition of 3-Chloroperoxybenzoic Acid by Immobilized Catalase in a Non-Aqueous Medium
	Abstract	Catalytic activities of catalase (C A T) immobilized on graphite -G M Z ™ , soot -"N O R IT " and "PM -100" to mediate decomposition of 3-C l-C 6H 4CO O O H (3-C P B A) in ace-tonitrile have been investigated. Under these conditions, the kinetic param eters K m, k, E a, ^ a x , and Zo were calculated. Conclusions on a probable mechanism of the catalytic process observed were drawn from the calculated values of A G , AH , and AS*. A quantitative UV-spectrophotometrical approach was used as the basic analytical tool. The electrochem ical reduction of oxygen generated in enzyme catalysed 3-C P B A decomposition was examined with polarization curves method.
	Reference	Z. Naturforsch. 55c, 55—5 (2000); received February 22/September 28 1999
	Published	2000
	Keywords	Catalase, Immobilized Enzyme, Carbon Materials, Acetonitrile Medium, Catalytic Activity
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	TEI-XML for	default:Reihe_C/55/ZNC-2000-55c-0055.pdf
	Identifier	ZNC-2000-55c-0055
	Volume	55

5	Author	P. Grunwald, W. G. Unßer, K. P. Pfaff, R. K. Rause, K. Lutz	Requires cookie*
	Title	Zur Beeinflussung der Aktivität von adsorptiv auf eloxierten Aluminiumblechen immobilisierter Urease durch die Anodisier-Bedingungen The Influence o f Anodizing Conditions on the Activity o f Urease Immobilized to Anodized Sheet A lum inium
	Abstract	The activity of urease immobilized by adsorption on anodized sheet aluminium strongly depends on the method chosen for preparation of these carriers. If oxalic acid is applied as electrolyte, only the anodizing temperature significantly influences the activity of the prepara tions. In case of the well-known GS process, however, the activity is not only affected by the temperature, but also by other conditions of anodizing, for example the current density and the electrolyte concentration. For both methods the correlation between the topography of the carrier surfaces and the activity of enzyme immobilized to the surface is described.
	Reference	Z. Naturforsch. 35c, 819—823 (1980); eingegangen am 15. Februar/6. Mai 1980
	Published	1980
	Keywords	Immobilized Enzymes, Urease, Anodized Sheet Aluminium, Surface Structure, Scanning Elec tron Microscopy
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	TEI-XML for	default:Reihe_C/35/ZNC-1980-35c-0819.pdf
	Identifier	ZNC-1980-35c-0819
	Volume	35

6	Author	ElenaG. Horozova, NinaD. Dimcheva, ZinaidaJ. Jordanova	Requires cookie*
	Title	Study of Xanthine Oxidase Immobilized Electrode Based on Modified Graphite
	Abstract	Xanthine oxidase (E . C. 1.2.3.2) was immobilized by adsorption on electrochem ically modi fied graphite plate to obtain an enzyme electrode. The current of the enzyme electrode in substrate (xanthine) solutions was found to be a result of the electrooxidation of H 20 2 gener ated in the enzyme layer. The linearity of the amperometric signal was up to a substrate concentration of 65 ^im at 0.6 V (vs. Ag/A gCl). The response time was 2 minutes. The enzyme electrode preserves 80% of its initial activity after perature.
	Reference	Z. Naturforsch. 55c, 60—6 (2000); received O ctober 5/Novem ber 10 1999
	Published	2000
	Keywords	Xanthine Oxidase, Immobilized Enzyme, Modified Graphite, Hydrogen Peroxide, Enzym e Electrode
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	TEI-XML for	default:Reihe_C/55/ZNC-2000-55c-0060.pdf
	Identifier	ZNC-2000-55c-0060
	Volume	55