Effect of organic solvents on stability and activity of two related alcohol dehydrogenases: a comparative study

Miroliaei, Mehran; Nemat‐Gorgani, Mohsen

doi:10.1016/s1357-2725(01)00109-1

Cited by 57 publications

(31 citation statements)

References 27 publications

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“…Bovara et al [3] reported that water activity ranging from <0.1 to 0.53 does not influence the enantioselectivity of enzymes in organic solvents using lipase PS and lipoprotein lipase as models. Miroliaei and Nemat-Gorgani [20] reported that the thermophilic alcohol dehydrogenase from Thermoanaerobacter brockii remains approx. 80% of its original activity at 90˝C in n-octane (log P = 4.183).…”

Section: Effect Of Log P Value Of Organic Solventmentioning

confidence: 99%

“…Kamat et al [89] studied the effect of pressure on the lipase activity in SC-fluoroform, and found that the activity reached maximum value near the critical point of fluoroform, and then gradually approached zero as pressure increased. In our previous work, we evaluated the effects of SC-CO 2 pretreatment, including pressure (6 and 10 MPa), exposure time (20,30, and 150 min) and temperature (35 and 40˝C), on the conformation (e.g., secondary and tertiary structures) and catalytic properties (e.g., residual activity, kinetics constants (K m and V max ), activation energies (E α ), thermo-stability, and organic solvent tolerance) of two commercial enzymes CALB and lipase PS in their solution forms. Results showed that the catalytic activities and kinetic constants of both lipases were markedly altered by SC-CO 2 pretreatment due to the changes of α-helix content in the secondary structure as well as tertiary structure of the enzymes [8].…”

Section: Effects Of Pressure and Temperature On The Structure And Actmentioning

confidence: 99%

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Enzyme Stability and Activity in Non-Aqueous Reaction Systems: A Mini Review

et al. 2016

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Abstract:Enormous interest in biocatalysis in non-aqueous phase has recently been triggered due to the merits of good enantioselectivity, reverse thermodynamic equilibrium, and no water-dependent side reactions. It has been demonstrated that enzyme has high activity and stability in non-aqueous media, and the variation of enzyme activity is attributed to its conformational modifications. This review comprehensively addresses the stability and activity of the intact enzymes in various non-aqueous systems, such as organic solvents, ionic liquids, sub-/super-critical fluids and their combined mixtures. It has been revealed that critical factors such as Log P, functional groups and the molecular structures of the solvents define the microenvironment surrounding the enzyme molecule and affect enzyme tertiary and secondary structure, influencing enzyme catalytic properties. Therefore, it is of high importance for biocatalysis in non-aqueous media to elucidate the links between the microenvironment surrounding enzyme surface and its stability and activity. In fact, a better understanding of the correlation between different non-aqueous environments and enzyme structure, stability and activity can contribute to identifying the most suitable reaction medium for a given biotransformation.

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Section: Effect Of Log P Value Of Organic Solventmentioning

confidence: 99%

Section: Effects Of Pressure and Temperature On The Structure And Actmentioning

confidence: 99%

Enzyme Stability and Activity in Non-Aqueous Reaction Systems: A Mini Review

et al. 2016

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“…These data suggest that inactivation of inorganic pyrophosphatase by alcohols depends on the hydrophobicity of the solvent. Other investigators have made similar observations using pure organic solvents (Lopes and Sola-Penna 2001, Klibanov 1989, Miroliaei and Nemat-Gorgani 2002, Fágáin 1995, Zaks and Klibanov 1988, Ahern and Klibanov 1985, Lopes et al 1999, Volkin et al 1991. These investigators have concluded that in high hydrophobic media, enzyme exposes hydrophobic regions that would lead to an inactivation of the catalyst.…”

Section: Resultsmentioning

confidence: 74%

“…Since the characterized properties of an enzyme in aqueous environment may be dramatically altered by the substitution of water with organic solvents (Klibanov 1989) a clear understanding of the structure-function relationship between the solvent of choice and the enzyme would provide useful in-700 RODRIGO GRAZINOLI-GARRIDO and MAURO SOLA-PENNA formation for many practical purposes (Miroliaei and Nemat-Gorgani 2002). It has been suggested that both the unfolding and inactivation events of the conventional N↔U→I model can be markedly decreased in hydrophobic media (Fágáin 1995).…”

Section: Introductionmentioning

confidence: 99%

Inactivation of yeast inorganic pyrophosphatase by organic solvents

Grazinoli-Garrido

Sola‐Penna

2004

An. Acad. Bras. Ciênc.

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A number of application for enzymes in organic solvents have been developed in chemical processing, food related conversions and analyses. The only unsolved problem related to nonaqueous enzymology is the notion that enzymes in organic solvent are mostly far less active than in water. Therefore, studies concerning the mechanisms by which enzymes are inactivated by organic solvents would reveal a clear understanding of the structure-function relationship of this phenomenon. Here we analyzed the effects of a series of alcohols (methanol, ethanol, 1-propanol and 2-propanol) and acetone on the activity of yeast inorganic pyrophosphatase. We observed that solvents inactivated the enzyme in a dose-dependent manner. This inactivation is also dependent on the hydrophobicity of the solvent, where the most hydrophobic solvent is also the most effective one. The I 50 for inactivation by n-alcohols are 5.9 ± 0.4, 2.7 ± 0.1 and 2.5 ± 0.1 M for methanol, ethanol and 1-propanol, respectively. Inactivation was less effective at 37 • C than at 5 • C, when the I 50 for inactivation by methanol, ethanol and 1-propanol are 4.5±0.2, 2.1±0.2 and 1.7±0.1 M, respectively. Our proposal is that solvent binds to the enzyme structure promoting the inactivation by stabilizing an unfolded structure, and that this binding is through the hydrophobic regions of either the protein or the solvent.

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“…33,34 For instance, the addition of alcohol is known to stabilize the helical structures of proteins, but to destabilize their tertiary structures; 2,35 -39 the combined effects may induce partially folded structures. Cytochrome c has been reported to assume a compact denatured conformer in 25% methanol at pH 3; 38 this state has no specific tertiary structure, but it has a secondary structural content.…”

Section: -19mentioning

confidence: 99%

Using mass spectrometry to probe the subtle differences in conformations of several cytochromes c in aqueous and methanol solutions

Wang

2004

J. Mass Spectrom.

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We have detected, using electrospray mass spectrometry, minor changes in the H/D exchange rates in various solvents for cytochromes c obtained from five different species. We compared the exchange rates exhibited by these proteins by mixing horse cytochrome c with each of the other four species and monitoring their exchanges simultaneously by mass spectrometry. The use of horse cytochrome c as a reference allowed us to make very accurate comparisons of the small differences in hydrogen exchange rates among the various species. The exchange experiments were performed in water and methanol at several concentrations in an effort to determine whether the cytochromes c of these five species have different conformations in specific solvents, which would cause their exchange rates to differ. Therefore, monitoring the level of exchange as a function of time in both water and water-methanol mixtures is a method for detecting subtle structural changes of proteins in their native or unfolded intermediate states.

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Effect of organic solvents on stability and activity of two related alcohol dehydrogenases: a comparative study

Cited by 57 publications

References 27 publications

Enzyme Stability and Activity in Non-Aqueous Reaction Systems: A Mini Review

Enzyme Stability and Activity in Non-Aqueous Reaction Systems: A Mini Review

Inactivation of yeast inorganic pyrophosphatase by organic solvents

Using mass spectrometry to probe the subtle differences in conformations of several cytochromes c in aqueous and methanol solutions

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