The principles of enzymes stabilization

Martínek, Karel; Levashov, Andrey V.; Klyachko, Natalia L.; Пантин, Владимир Игоревич; Березин, И.В.

doi:10.1016/0005-2744(81)90151-0

Cited by 191 publications

(61 citation statements)

References 45 publications

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“…Consequently, separation of photoproducts is achieved, and back-electron-transfer reactions are hindered. Another important feature is that the enzyme stability in reversed micelles is sometimes greater than in aqueous solution (7,9). This was also the case in our system with hydrogenase from D. vulgaris.…”

Section: Resultssupporting

confidence: 61%

“…Several authors have reported that enzymes can be dissolved in organic solvents with the aid of surfactants while retaining their activity (7)(8)(9). According to recent models (14,15), the protein is confined to the water pool in the reversed micelle.…”

Section: Resultsmentioning

confidence: 99%

“…Hence, the study of structural and catalytic properties of enzymes can be extended to organic media. To date, several enzymes, such as trypsin, a-chymotrypsin, lactate dehydrogenase, peroxidase, and lysozyme have been encapsulated in the aqueous core of reversed micelles (7)(8)(9).…”

mentioning

confidence: 99%

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Photosensitized production of hydrogen by hydrogenase in reversed micelles

Hilhorst

Laane

Veeger

1982

Proc. Natl. Acad. Sci. U.S.A.

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Hydrogenase (hydrogen:ferricytochrome c3 oxidoreductase, EC 1. 12.2. 1) from Desulfovibrio vulgaris was encapsulated in reversed micelles with cetyltrimethylammonium bromide as surfactant and a chloroform/octane mixture as solvent. Reducing equivalents for hydrogenase-catalyzed hydrogen production were provided-by vectorial photosensitized electron.transfer from a donor (thiophenol) in the organic phase through a surfactant-Ru2, sensitizer located in the interphase to methyl viologen concentrated in the aqueous core ofthe reversed micelle. The results show that reversed micelies provide a microenvironment that (i) stabilizes hydrogenase against inactivation and (ii) allows an efficient vectorial photosensitized electron and proton flow from the organic phase to hydrogenase in the aqueous phase.It has been well established that surfactant molecules dissolved in organic solvents aggregate to reversed micelles in the presence of small amounts of water. Reversed micelles are of multiple interest for they create a microenvironment that provides a unique reaction medium.An area of active current research is the photochemical investigation of these organized structures with the aim of obtaining structural characteristics (1-3) and of modeling natural processes such as photosynthesis (4-6). The latter objective is of particular interest because it includes potential applications such as solar energy conversion and storage. Essential for efficient solar energy conversion and storage is the separation of photoproducts formed in photosensitized electron transfer reactions. Recently, Willner et aL (5) showed that effective separation ofphotoproducts can be achieved in a reversed micellar system by vectorial photosensitized electron transfer from a donor in the organic phase to an acceptor in the water pool and vice versa.In addition, the application of reversed micelles in enzyme catalysis increases. Reversed micelles have been shown to provide a microenvironment for enzymes that protects them from the unfavorable action of organic solvents by means of surfactants. Hence, the study of structural and catalytic properties of enzymes can be extended to organic media. To date, several enzymes, such as trypsin, a-chymotrypsin, lactate dehydrogenase, peroxidase, and lysozyme have been encapsulated in the aqueous core of reversed micelles (7-9).In this study we entrapped hydrogenase (hydrogen:ferricytochrome c3 oxidoreductase, EC 1.12.2.1) from Desulfovibrio vulgaris in a reversed cetyltrimethylammonium bromide micelle; the objective was to obtain a highly organized system for an efficient coupling between hydrogenase and a photochemical system that produces reducing equivalents and protons necessary for hydrogenase action.

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Section: Resultssupporting

confidence: 61%

Section: Resultsmentioning

confidence: 99%

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Photosensitized production of hydrogen by hydrogenase in reversed micelles

Hilhorst

Laane

Veeger

1982

Proc. Natl. Acad. Sci. U.S.A.

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“…EI-Nokaly35) indicated that at high surfactant concentrations (low W o ), the high-molecular-weight triacylglycerols may be too bulky to penetrate the interfacial film to be interesterified by lipase. Martinek et al 22) showed that by varying the concentration of water and maintaining a constant concentration of the surfactant, interfacial structure and other characteristics of micelles can be much altered. Luisi and Staub 37 ) concluded that the radii of the reverse micelles as well as several of their physical properties depend most on the ratios of the molar concentrations of water and surfactant.…”

Section: Effect Of Water Concentration On Interesterijication Reactionmentioning

confidence: 99%

Interestification of Butterfat by Lipase fromRhizopus niveusin Reverse Micellar Systems

Safari

Kermasha

Lamboursain

et al. 1994

Bioscience, Biotechnology, and Biochemistry

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“…A modificação de enzimas com polietilenoglicol que resulta em um pó solúvel em benzeno ou em hidrocarbonetos clorados, também tem sido empregada [18][19][20][21][22] . Outras técnicas que superam os problemas da baixa solubilidade dos substratos, são o uso de surfactantes e micelas reversas [23][24][25][26][27][28][29][30][31][32][33][34][35][36] . Na última década, muitos estudos têm se voltado para a utilização de microemulsões para imobilização de enzimas [37][38][39][40][41][42][43][44] .…”

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Organo-gel: um novo sistema para a imobilização de lipases e sua aplicação em síntese orgânica

et al. 1997

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o C. This methodology is described as a new alternative for the use of enzymes in organic solvents. High enzymic stability has been observed. We have also used this methodology for the successful resolution of chiral secondary alcohols. This is a convenient way of using this catalyst in organic solvents which employs small amounts of the enzyme (250µg/mL).Keywords: lipases; immobilization; organogels. DIVULGAÇÃO INTRODUÇÃOA habilidade das enzimas para atuarem como catalisadores já tem sido considerada por muitos anos, particularmente pela indústria farmacêutica [1][2][3][4] . A imobilização de enzimas é uma das técnicas mais importantes na aplicação de catálise enzimática para reações sintéticas em solventes orgânicos [5][6][7][8][9][10] . Por razões prática e econômica, é muitas vezes vantajoso usar enzimas imobilizadas visto que, com poucas exceções, elas são insolú-veis em solventes orgânicos 11 . Uma das grandes vantagens da imobilização é poder utilizar o catalisador repetidamente sem considerável perda da atividade catalítica 12 . Considerando a compatibilidade com a enzima, géis hidrofílicos têm sido frequentemente empregados como suportes enzimáticos. Às vezes, a enantiosseletividade é aumentada 12 . Alguns sistemas que já foram usados para imobilizar enzimas são Eupergit C 13 , celite 11,14,15 , quitosana e quitina 11 , agarose, Chromosorb e Sepharose 13,16,17 . A modificação de enzimas com polietilenoglicol que resulta em um pó solúvel em benzeno ou em hidrocarbonetos clorados, também tem sido empregada [18][19][20][21][22] . Outras técnicas que superam os problemas da baixa solubilidade dos substratos, são o uso de surfactantes e micelas reversas [23][24][25][26][27][28][29][30][31][32][33][34][35][36] . Na última década, muitos estudos têm se voltado para a utilização de microemulsões para imobilização de enzimas [37][38][39][40][41][42][43][44] . Uma microemulsão é uma dispersão isotrópica e opticamente transparente de óleo em água (O/W) ou de água em óleo (W/O), onde o óleo é um solvente orgânico (hexano, heptano). O nome "microemulsão" deriva do fato de que gotas de óleo no sistema (O/W), ou gotas de água no sistema (W/O), possuem um diâmetro que varia de 50 a 500 Å 45,46 . Como as microemulsões são sistemas organizados, elas são fáceis de serem preparadas. A estabilidade da microemulsão depende da razão da concentração de água pelo surfactante adicionado ao meio, representado por W 0 , onde:A gota de microemulsão pode ser efetivamente considerada como um microreator. Robinson e col., estudando as propriedades das microemulsões, concluiram que a sua estabilidade depende da concentração de óleo, água e surfactante presentes no meio 43 . Haering, Luise 42 , Quellet e col. [47][48][49][50][51] descreveram o efeito da solubilização de gelatina em uma microemulsão água / óleo (W/O) na formação do gel. Este é obtido pelo resfriamento de uma solução previamente aquecida a 55°C de Aerosol-OT (sulfosuccinato sódico de bis-2-etilhexila) em solvente orgâni-co (hexano, heptano) e uma solução aquosa de gelatin...

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The principles of enzymes stabilization

Cited by 191 publications

References 45 publications

Photosensitized production of hydrogen by hydrogenase in reversed micelles

Photosensitized production of hydrogen by hydrogenase in reversed micelles

Interestification of Butterfat by Lipase fromRhizopus niveusin Reverse Micellar Systems

Organo-gel: um novo sistema para a imobilização de lipases e sua aplicação em síntese orgânica

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