Studies on the production of (S)-(+)-solketal (2,2-dimethyl-1,3-dioxolane-4-methanol) by enantioselective oxidation of racemic solketal with Comamonas testosteroni

Geerlof, Arie; Stoorvogel, J.; Jongejan, Jaap A.; Leenen, E.J.T.M.; Dooren, T. J. G. M. van; Tweel, W.J.J. van den; Duine, Johannis A.

doi:10.1007/bf00170216

Cited by 19 publications

(6 citation statements)

References 34 publications

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“…All strains of C. testosteroni investigated so far contain QH-EDH, those of C. acidovorans or C. terrigena do not (Geerlof et al, 1994b). QH-EDH is produced in the apo form, that is one haem c molecule/enzyme molecule is present but PQQ is not (Groen et al, 1986).…”

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confidence: 96%

Description of the Kinetic Mechanism and the Enantioselectivity of Quinohaemoprotein Ethanol Dehydrogenase from Comamonas testosteroni in the Oxidation of Alcohols and Aldehydes

Geerlof

Rakels

Straathof

et al. 1994

European Journal of Biochemistry

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Initial rate studies were performed on the oxidation of (racemic) alcohols as well as aldehydes by quinohaemoprotein ethanol dehydrogenase, type 1, from Comamonas testosteroni with potassium ferricyanide as electron acceptor. The data could be fitted with an equation derived for a mechanism (hexa-uni ping-pong) in which alcohols are oxidized to the corresponding carboxylic acids and the intermediate aldehyde becomes released from the enzyme. However, for some substrates it was necessary to assume that they exert uncompetitive inhibition. The same model was used to fit the data of conversion processes. Reversible inactivation of the enzyme takes place during the conversion, the extent being inversely proportional to the concentration of ferricyanide present at the start. From the values of the kinetic parameters obtained for (R)-and (S)-solketal [2,2-dimethyl-4-(hydroxymethyl)-l,3-dioxolane] and their corresponding aldehydes, it appeared that the second step in (S)-solketal conversion is much faster than the first one and that opposite enantiomeric preferences exist for the alcohol and the aldehyde substrates. Since the initial rate measurements as well as the progress curve analysis gave similar kinetic parameter values and product analysis revealed intermediates in the amounts predicted, it is concluded that the kinetic and enantioselective behaviour of the enzyme is adequately described by the model presented here. Finally, the results indicate that both kinetic approaches should be used in conversions with consecutive reactions since they provide complementary information.Quinohaemoprotein alcohol dehydrogenases catalyze the oxidation of a broad range of (primary) alcohols as well as aldehydes. As reflected by their name, they contain two different types of cofactor, namely pyrroloquinoline quinone (PQQ) and haem c. This type of alcohol dehydrogenase occurs in Acetobacter (Adachi et al., 1978a), Gluconobacter (Adachi et al., 1978b), Pseudomonas (Matsushita et al., 1993), and Comamonas (Groen et al., 1986) bacteria grown on alcohols with oxygen as electron acceptor. Significant differences exist between the enzymes of this group with respect to structure and specificity. For that reason, the enzyme from Comamonas testosteroni is indicated as quinohaemo- Abbreviations. E, enantiomeric ratio; EL, midpoint potential under physiological conditions (at 1 mM, 25°C and pH 7); QH-EDH, quinohaemoprotein ethanol dehydrogenase; (R)-BrMePrOH, (R)-3-bromo-2-methyl-1 -propano1 ; PQQ, pyrroloquinoline quinone (2,7,9-tricarboxy-lH-pyrrolo[2,3-flquinoline-4,5-dione).

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confidence: 96%

Description of the Kinetic Mechanism and the Enantioselectivity of Quinohaemoprotein Ethanol Dehydrogenase from Comamonas testosteroni in the Oxidation of Alcohols and Aldehydes

Geerlof

Rakels

Straathof

et al. 1994

European Journal of Biochemistry

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“…Comparable studies with other quinohemoprotein ADHs were preferentially carried out using industrial relevant alcohols as substrates, e.g., solketal and glycidol (14)(15)(16)(17)29). QH-EDH from C. testosteroni, which showed the highest activity and E value for solketal, had the same preference for the R-(Ϫ)-alcohol as that observed for THFA-DH.…”

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confidence: 99%

Catalytic and Molecular Properties of the Quinohemoprotein Tetrahydrofurfuryl Alcohol Dehydrogenase from Ralstonia eutropha Strain Bo

2001

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The quinohemoprotein tetrahydrofurfuryl alcohol dehydrogenase (THFA-DH) from Ralstonia eutropha strain Bo was investigated for its catalytic properties. The apparent k cat /K m and K i values for several substrates were determined using ferricyanide as an artificial electron acceptor. The highest catalytic efficiency was obtained with n-pentanol exhibiting a k cat /K m value of 788 ؋ 10 4 M ؊1 s ؊1 . The enzyme showed substrate inhibition kinetics for most of the alcohols and aldehydes investigated. A stereoselective oxidation of chiral alcohols with a varying enantiomeric preference was observed. Initial rate studies using ethanol and acetaldehyde as substrates revealed that a ping-pong mechanism can be assumed for in vitro catalysis of THFA-DH. The gene encoding THFA-DH from R. eutropha strain Bo (tfaA) has been cloned and sequenced. The derived amino acid sequence showed an identity of up to 67% to the sequence of various quinoprotein and quinohemoprotein dehydrogenases. A comparison of the deduced sequence with the N-terminal amino acid sequence previously determined by Edman degradation analysis suggested the presence of a signal sequence of 27 residues. The primary structure of TfaA indicated that the protein has a tertiary structure quite similar to those of other quinoprotein dehydrogenases.

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“…8). 28, 29 Unfortunately, however, only low levels of substrate concentration are allowed, otherwise severe inhibition occurs 30. Although this can be circumvented by using cells with higher aldehyde dehydrogenase content (the aldehyde forms are more inhibitory than the alcohol forms), this is only partial, so that further research is necessary before practical applications can be expected.…”

Section: Applicationsmentioning

confidence: 99%

Cofactor diversity in biological oxidations: Implications and applications

Duine

2001

Chem. Record

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Until recently, it was generally believed that enzymatic oxidation and reduction requires the participation of either a nicotinamide (NAD(P)+) or a flavin (FAD, FMN), in agreement with the existence of NAD(P)/H-dependent dehydrogenases/reductases and flavoprotein dehydrogenases/reductases/oxidases. However, during the past 20 years, the unraveling of the enzymology of the oxidation and reduction of C1-compounds by bacteria has led to the discovery of many new redox cofactors, some of them discussed here as they have a wider physiological significance than just enabling enzymatic C1-conversions to occur. A good example is the quinone cofactors, encompassing PQQ (2,7,9-tricarboxy-1H-pyrrolo[2,3-f]-quinoline-4,5-dione), TTQ (tryptophyl tryptophanquinone), TPQ (topaquinone), LTQ (lysyl topaquinone), and several others whose structures have still to be elucidated. Another example is mycothiol (1-O-(2'-[N-acetyl-L-cysteinyl]amido-2'-deoxy-alpha-D-glucopyranosyl)-D-myo-inosoitol), the counterpart of glutathione, once thought to be a universal coenzyme. Because these novel cofactors assist in reactions that can also be catalyzed by already known enzyme "classic cofactor" combinations, and first indications suggest that the chemistry of the reactions is not unique, one may wonder about the evolutionary background for this cofactor diversity. However, as will be illustrated by examples, from a practical point of view the diversity is beneficial, as it has increased the arsenal of enzymes suitable for application.

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Studies on the production of (S)-(+)-solketal (2,2-dimethyl-1,3-dioxolane-4-methanol) by enantioselective oxidation of racemic solketal with Comamonas testosteroni

Cited by 19 publications

References 34 publications

Description of the Kinetic Mechanism and the Enantioselectivity of Quinohaemoprotein Ethanol Dehydrogenase from Comamonas testosteroni in the Oxidation of Alcohols and Aldehydes

Description of the Kinetic Mechanism and the Enantioselectivity of Quinohaemoprotein Ethanol Dehydrogenase from Comamonas testosteroni in the Oxidation of Alcohols and Aldehydes

Catalytic and Molecular Properties of the Quinohemoprotein Tetrahydrofurfuryl Alcohol Dehydrogenase from Ralstonia eutropha Strain Bo

Cofactor diversity in biological oxidations: Implications and applications

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