Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Studies on the thermal inactivation of immobilized enzymes (1986)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 28 (1986), S. 511-522 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The thermal inactivation of a great number of immobilized enzymes shows a biphasic kinetics, which distinctly differs from the first-order inactivation kinetics of the corresponding soluble enzymes. As shown for α-amylase, chymotrypsin, and trypsin covalently bound to silica, polystyrene, or polyacrylamide, the dependence of the remaining activities on the heating time can be well described by the sum of two exponential terms. To interpret this mathematical model function, the catalytic properties of immobilized enzymes (number of active sites in silica-bound trypsin, KM and Ea values in silica-bound α-amylase and chymotrypsin) at different stages of inactivation and the influence of various factors (coupling conditions, addition of denaturants or stabilizers, etc.) on the thermal inactivation of silica-bound α-amylase were studied. Furthermore, conformational alterations in the thermal denaturation of spin-labeled soluble and silica-bound β-amylase were compared by electron spin resonance (ESR) studies. The results suggest that the biphasic inactivation kinetics reflects two different pathways according to which catalytically identical enzyme molecules are predominantly inactivated.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260280407
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Invertase-catalyzed reactions in alcoholic solutions (1990)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 35 (1990), S. 1006-1010 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The formation of alkyl β-D-fructofuranosides by invertase from sucrose in aqueous solutions of methanol, ethanol, or n-propanol is studied for the dependence on alcohol and invertase concentrations as well as on reaction time. The yield of alkyl β-D-fructosides is shown to be controlled by three competitive reactions: the alcoholysis of sucrose, the hydrolysis of sucrose, and the hydrolysis of alkyl β-D-fructosides. Both the conversion rate of sucrose and the fraction of alkyl β-D-fructosides in the product mixture are dependent on the chain length of the alcohols. They decrease in the sequence methanol 〉 ethanol 〉 n-propanol. Alkyl β-D-fructosides are also formed by invertase starting from alcoholic solutions of fructose.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260351008
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Protein adsorption and leakage in carrier-enzyme systems (1991)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 37 (1991), S. 280-287 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The capability of binding enzymes adsorptively to unmodified and silanized silica and glass as well as modified polystyrene carriers was studied for α-amylase, β-amylase, and α-chymotrypsin. In most cases a high percentage of protein was bound very firmly under considerable loss of activity. The leakage of protein from the carriers was studied by measuring the intrinsic protein fluorescence on β-amylase adsorptively bound to aminopropyl silica, aminomethyl, and hexadecylaminomethyl polystyrene. It was compared with the leakage of β-amylase covalently bound to the same carriers via glutaraldehyde, trichloro-triazine, or benzoquinone. In the absence and in the presence of substrate, at 25 and at 60°C, the leakage rates of the adsorptively bound enzymes were not higher than in the covalently bound systems. The poorest binding stability was found in benzoquinone-coupled β-amylase derivatives. It is even reduced at higher temperatures, whereas the temperature did not show any remarkable influence on the leakage of the other derivatives. In adsorptively as well as in all the covalently bound systems, the presence of substrate did not promote the protein leakage.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260370311
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...