A new strategy for the study of oligomeric enzymes: γ-glutamyltransferase in reversed micelles of surfactants in organic solvents

Two isoenzymes of Candida rugosa lipase, having the same mol.wt., size and similar aminoacid sequence, were studied in reverse micelles of AOT. The results demonstrated the relevance of lipase hydrophobicity in reactions in anionic micelles. This is a key factor in mitigating the inhibition effect of charged micelles. The more hydrophobic isolipase A was a better biocatalyst for hydrolytic processes in these systems. Its a-helix content increased from 31% to 49% of the total structure in reverse micelles. A fluorescence study indicated a more apolar environment for the more hydrophobic isolipase A. Emission spectra of this isolipase in the AOT systems were blue shifted. At ~0 values where each isolipase presented its maximum activity, a decrease of the emission intensity of Trp was found. An enzyme and substrate dependence of optimal ¢o o is reported. The different interaction of isolipases A and B with the micellar system produced an opposite coo dependence to their stabilities. The more hydrophobic lipase A had higher stability at higher droplet sizes.

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“…Lipases A and B have the same molecular mass, similar amino *Corresponding author. Fax: (34) (1) 5854760.…”

Section: Introductionmentioning

confidence: 99%

Influence of the hydrophobicity of lipase isoenzymes from Candida rugosa on its hydrolytic activity in reverse micelles

1995

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“…If the dimensions of the internal cavity of the micelle are less than the dimensions of the protein globule, the micelle is formed around the protein molecule with retaining the initial value of the hydration degree (the model of induced coincidence) (3,11,12). The varying of the [water]/[surt'actant] ratio allows the associates of the enzyme with different oligomeric state to be obtained or, on the contrary, the dissociation of the enzymes under mild conditions to be provoked (1)(2)(3)(4)(5)(6)(7). Entrapping the oligomeric enzyme in the internal cavity of the hydrated reversed micelle may result in the significant changes in the packing of the subunits and, as a result, the changes in the dimensions and shape of the oligomeric complexes.…”

Section: Introductionmentioning

confidence: 99%

“…The systems of hydrated reversed miceUes of surfactant in organic solvent are very suitable models for studying the oligomeric state of multisubunit enzymes (1)(2)(3)(4)(5)(6)(7)(8). Hydrated reversed rnicelles of aerosol OT (AOT) in octane are characterized by sharp distribution over the micelle dimensions, the dimensions of the internal cavity of the micelles are strictly determined by the degree of hydration of surfactant, i.e., the ratio [water]/[surfactant] = w0 (9)(10).…”

Section: Introductionmentioning

confidence: 99%

Sedimentation analysis of muscle glycogen phosphorylase b entrapped in hydrated reversed micelles of aerosol OT in octane

Kurganov

Chebotareva

1999

IUBMB Life

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SUMMARY:The oligomeric state and formation of supramolecular structures of glycogen phosphorylase b from rabbit skeletal muscles have been studied in the system of hydrated reversed micelles of aerosol OT (AOT) in octane. Sedimentation studies show that the oligomeric state of the enzyme is controlled by the degree of hydration of micelles. Monomeric, dimeric, trimeric, tetrameric, hexameric, or octameric forms of the enzyme were observed depending on the degree of micelle hydration.

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“…In elegant works of Levashov and coworkers (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11) it was demonstrated that the systems of hydrated reversed micelles of surfactant in organic solvent may serve as an effective tool for the study of the structure and function of oligomeric enzymes. The hydrated reversed micelles of aerosol OT (ACT) in octane are especially convenient for this aim.…”

Section: Introductionmentioning

confidence: 99%

Behavior of uridine phosphorylase from Escherichia coli K‐12 in hydrated reversed micelles of surfactant in organic solvent

et al. 1997

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SUMMARY:The catalytic activity of uridine phosphorylase from Escherichia coli K-12 entrapped in hydrated reversed micelles of aerosol OT (ACT) in octane has been studied as a function of the degree of hydration of micelles. It was shown that the catalytic activity reaches maximum values at ratios [H20]/[AOT ] equal to 8.4, 12.8, 16.1, and 18.6. On the basis of sedimentation data the conclusion has been made that the maximums of the catalytic activity of uridine phosphorylase correspond to monomefic, dimeric, trimeric, and tetrameric forms of the enzyme.

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A new strategy for the study of oligomeric enzymes: γ-glutamyltransferase in reversed micelles of surfactants in organic solvents

Cited by 34 publications

References 23 publications

Influence of the hydrophobicity of lipase isoenzymes from Candida rugosa on its hydrolytic activity in reverse micelles

Influence of the hydrophobicity of lipase isoenzymes from Candida rugosa on its hydrolytic activity in reverse micelles

Sedimentation analysis of muscle glycogen phosphorylase b entrapped in hydrated reversed micelles of aerosol OT in octane

Behavior of uridine phosphorylase from Escherichia coli K‐12 in hydrated reversed micelles of surfactant in organic solvent

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