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- Larsson, Karin M., et al.
(författare)
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Activity and stability of horse‐liver alcohol dehydrogenase in sodium dioctylsulfosuccinate/cyclohexane reverse micelles
- 1987
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Ingår i: European Journal of Biochemistry. - : Wiley. - 0014-2956 .- 1432-1033. ; 166:1, s. 157-161
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Tidskriftsartikel (refereegranskat)abstract
- Horse liver alcohol dehydrogenase (EC 1.1.1.1) solubilized in sodium dioctylsulfosuccinate (AOT)/cyclohexane reverse micelles was used for the oxidation of ethanol and reduction of cyclohexanone in a coupled substrate/coenzyme recycling system. The activity of the enzyme was studied as a function of pH and water content. The enzyme was optimally active in microemulsions prepared with buffer of pH around 8. An increase in enzymatic activity was observed as a function of increasing water content. The Km values for the substrates were calculated based on the total reaction volume. The apparent Km for ethanol in reverse micelles was about eight times lower as compared to that in buffer solution, whereas the Km for cyclohexanone was almost unaltered. Storage and operational stability were investigated. It was found that the specific activity of the alcohol dehydrogenase operating in reverse micellar solution was good for at least two weeks. The steroid eticholan‐3ß‐ol‐17‐one was also used as a substrate. In this case the reaction rate was approximately five times higher in a reverse micellar solution than in buffer.
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| 2. |
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| 3. |
- RESLOW, Mats, et al.
(författare)
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On the importance of the support material for bioorganic synthesis : Influence of water partition between solvent, enzyme and solid support in water‐poor reaction media
- 1988
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Ingår i: European Journal of Biochemistry. - : Wiley. - 0014-2956 .- 1432-1033. ; 172:3, s. 573-578
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Tidskriftsartikel (refereegranskat)abstract
- α‐Chymotrypsin was adsorbed on solid support materials and the catalytic activity of the preparations in organic solvents was studied. The activity was highly dependent on the nature of the support material and on the amount of water present in the reaction mixture. There appears to be competition for the water in the system between the enzyme, the support material and the solvent. The support materials were characterized by measuring their ability to absorb water from water‐saturated diisopropyl ether. For the quotient: (amount of water on the support)/(amount of water in the solvent) in the model system the term aquaphilicity was proposed. The activity of adsorbed chymotrypsin in diisopropyl ether decreased with increasing aquaphilicity of the support material. The same trend was observed when the activity of horse liver alcohol dehydrogenase adsorbed on different supports was measured in diisopropyl ether.
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