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Reverse micellar modified mixed anionic and zwitterionic surfactant system for antibiotic extraction. Sep Purif Technol 2019. [DOI: 10.1016/j.seppur.2019.115816] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Chin M, Somasundaran P. Enzyme Activity and Structural Dynamics Linked to Micelle Formation: A Fluorescence Anisotropy and ESR Study. Photochem Photobiol 2013; 90:455-62. [DOI: 10.1111/php.12207] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Accepted: 10/24/2013] [Indexed: 11/27/2022]
Affiliation(s)
- Michael Chin
- Earth and Environmental Engineering; Columbia University; New York NY
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4
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Yeung PSW, Eskici G, Axelsen PH. Infrared spectroscopy of proteins in reverse micelles. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2012; 1828:2314-8. [PMID: 23098833 DOI: 10.1016/j.bbamem.2012.10.019] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2012] [Accepted: 10/14/2012] [Indexed: 11/28/2022]
Abstract
Reverse micelles are a versatile model system for the study of crowded microenvironments containing limited water, such as those found in various tissue spaces or endosomes. They also preclude protein aggregation. Reverse micelles are amenable to study by linear and nonlinear infrared spectroscopies, which have demonstrated that the encapsulation of polypeptides and enzymatically active proteins into reverse micelles leads to conformational changes not seen in bulk solution. The potential value of this model system for understanding the folding and kinetic behavior of polypeptides and proteins in biologically important circumstances warrants increased study of reverse micelle systems by infrared spectroscopy. This article is part of a Special Issue entitled: FTIR in membrane proteins and peptide studies.
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Affiliation(s)
- Priscilla S-W Yeung
- Department of Pharmacology, University of Pennsylvania, Philadelphia, PA 19104, USA
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Naskar B, Dan A, Ghosh S, Aswal V, Moulik SP. Revisiting the self-aggregation behavior of cetyltrimethylammonium bromide in aqueous sodium salt solution with varied anions. J Mol Liq 2012. [DOI: 10.1016/j.molliq.2012.03.020] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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6
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Yeung PSW, Axelsen PH. The Crowded Environment of a Reverse Micelle Induces the Formation of β-Strand Seed Structures for Nucleating Amyloid Fibril Formation. J Am Chem Soc 2012; 134:6061-3. [DOI: 10.1021/ja3004478] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Priscilla S.-W. Yeung
- Departments of †Pharmacology, ‡Biochemistry and
Biophysics, and §Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United
States
| | - Paul H. Axelsen
- Departments of †Pharmacology, ‡Biochemistry and
Biophysics, and §Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United
States
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Hebbar HU, Hemavathi AB, Sumana B, Raghavarao KSMS. Reverse Micellar Extraction of Bromelain from Pineapple (Ananas comosusL. Merryl) Waste: Scale-up, Reverse Micelles Characterization and Mass Transfer Studies. SEP SCI TECHNOL 2011. [DOI: 10.1080/01496395.2011.572110] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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8
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Verhaert RMD, Hilhor R. Enzymes in reversed micelles: 4. Theoretical analysis of a one-substrate/one-product conversion and suggestions for efficient application. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/recl.19911100519] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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9
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Marhuenda-Egea FC, Piera-velázquez S, Cadenas C, Cadenas E. Kinetic Studies of an Extremely Halophilic Enzyme Entrapped in Reversed Micelles. BIOCATAL BIOTRANSFOR 2009. [DOI: 10.3109/10242420009015245] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Ballesteros A, Bornscheuer U, Capewell A, Combes D, Condoret JS, Koenig K, Kolisis FN, Marty A, Menge U, Scheper T, Stamatis H, Xenakis A. Review Article Enzymes in Non-Conventional Phases. BIOCATAL BIOTRANSFOR 2009. [DOI: 10.3109/10242429509040103] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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11
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Valis TP, Xenakis A, Kolisis FN. Comparative Studies of Lipase fromRhizopus Delemarin Various Microemulsion Systems. ACTA ACUST UNITED AC 2009. [DOI: 10.3109/10242429209065247] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Thomas P. Valis
- The National Hellenic Research Foundation, Institute of Biological Research, 48. Vas. Constantinou Ave., 11635, Athens, Greece
| | - Aristotelis Xenakis
- The National Hellenic Research Foundation, Institute of Biological Research, 48. Vas. Constantinou Ave., 11635, Athens, Greece
| | - Fragiskos N. Kolisis
- Dept. Chem. Eng., National Technical University of Athens, 9 Iroon Polytechniou Str., Campus, Zographou, 15773, Greece
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Avramiotis S, Lianos P, Xenakis A. Trypsin In Lecithin Based w/o Microemulsions. Fluorescence and Enzyme Activity Studies. BIOCATAL BIOTRANSFOR 2009. [DOI: 10.3109/10242429609110282] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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13
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Jing L, Li XJ, Han YC, Chu Y. The esterification in cyclohexane/DBSA/water microemulsion system. Colloids Surf A Physicochem Eng Asp 2008. [DOI: 10.1016/j.colsurfa.2008.05.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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14
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Biasutti MA, Abuin EB, Silber JJ, Correa NM, Lissi EA. Kinetics of reactions catalyzed by enzymes in solutions of surfactants. Adv Colloid Interface Sci 2008; 136:1-24. [PMID: 17706582 DOI: 10.1016/j.cis.2007.07.001] [Citation(s) in RCA: 141] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2006] [Revised: 06/30/2007] [Accepted: 07/02/2007] [Indexed: 11/20/2022]
Abstract
The effect of surfactants, both in water-in-oil microemulsions (hydrated reverse micelles) and aqueous solutions upon enzymatic processes is reviewed, with special emphasis on the effect of the surfactant upon the kinetic parameters of the process. Differences and similarities between processes taking place in aqueous and organic solvents are highlighted, and the main models currently employed to interpret the results are briefly discussed.
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Shaw AK, Pal SK. Activity of Subtilisin Carlsberg in macromolecular crowding. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2007; 86:199-206. [PMID: 17110125 DOI: 10.1016/j.jphotobiol.2006.10.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2006] [Revised: 10/06/2006] [Accepted: 10/10/2006] [Indexed: 11/17/2022]
Abstract
Enzymatic activity of a proteolytic enzyme Subtilisin Carlsberg (SC) in anionic sodium dodecyl sulfate (SDS) micellar medium has been explored and found to be retarded compared to that in bulk buffer. Circular dichroism (CD) study reveals that SDS, which is a potential protein denaturant, has an insignificant denaturation effect on SC. The structural integrity of the protein offers an opportunity to study the functionality of the enzyme SC in a macromolecular crowding of micelles. Dynamic light scattering (DLS) data indicates no sandwich-like micelle-SC complex formation ruling out the possibility of interaction of the enzyme with the hydrophobic core of the micelle. However, steady state and time resolved emission studies on specific and nonspecific fluorescent probes indicate the proximity effect at the surface of the enzyme due to macromolecular crowding of the micelles. The agreement of retarded enzymatic activity in the micellar crowd with a theoretical model ascribed to the facts that substrates are compartmentalized in the micelles and enzyme interacts with the micelle through stern layer.
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Affiliation(s)
- Ajay Kumar Shaw
- Unit for Nano Science and Technology, Department of Chemical, Biological and Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700 098, India
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Rodakiewicz-Nowak J, Ito M. Effect of AOT on enzymatic activity of the organic solvent resistant tyrosinase from Streptomyces sp. REN-21 in aqueous solutions and water-in-oil microemulsions. J Colloid Interface Sci 2006; 284:674-9. [PMID: 15780309 DOI: 10.1016/j.jcis.2004.10.052] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2004] [Accepted: 10/20/2004] [Indexed: 11/17/2022]
Abstract
The effect of AOT (sodium-bis(2-ethylhexyl sulfosuccinate)) on enzymatic activity of the organic solvent resistant tyrosinase (OSRT) in aqueous phosphate buffer solutions and in water-in-oil microemulsions of the water/AOT/isooctane system has been investigated. In contrast to mushroom tyrosinase, AOT does not activate OSRT in aqueous solutions, altering its activity very little at concentrations lower than 2 mM. Increasing contents of AOT in isooctane reduce the observed initial reaction rates of oxidation of t-butylcatechol (tBC) and 4-methylcatechol (4-MC). Similarly to mushroom tyrosinase, the effect has been described using an equation based on preferential binding of the substrates by surfactant interface layers. The apparent Michaelis-Menten substrate binding constants increase linearly with AOT concentration (with slopes of 0.12+/-0.02 and 0.051+/-0.006 for tBC and 4-MC, respectively), and the effective enzyme turnover number in the microemulsions remains practically constant.
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Affiliation(s)
- Janina Rodakiewicz-Nowak
- Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, 30 239 Kraków, Poland.
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Abuin E, Lissi E, Duarte R. Kinetics of N-glutaryl-L-phenylalanine p-nitroanilide hydrolysis catalyzed by α-chymotrypsin in aqueous solutions of dodecyltrimethylammonium bromide. J Colloid Interface Sci 2005; 283:539-43. [PMID: 15721931 DOI: 10.1016/j.jcis.2004.08.177] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2003] [Accepted: 08/26/2004] [Indexed: 11/20/2022]
Abstract
The rate of hydrolysis of N-glutaryl-L-phenylalanine p-nitroanilide (GPNA) catalyzed by alpha-chymotrypsin (alpha-CT) has been measured in aqueous solutions of dodecyltrimethylammonium bromide (DTAB) at concentrations below and above the critical micelle concentration, as well as in the absence of surfactant. Under all the conditions employed, the reaction follows a Michaelis-Menten mechanism. The presence of the surfactant leads to superactivity below and above the critical micelle concentration (CMC), with a maximum reaction rate taking place near the CMC when the results are treated in terms of the analytical concentration of the substrate. A similar behavior was observed by working with the enzyme partially deactivated in the presence of 4 M urea. After correction to take into account the partitioning of the substrate between the micelles and the external media, the activity of the enzyme tends to remain almost constant above the corresponding CMCs. This results from a compensation of a decrease in the catalytic constant (k(cat)) and a decrease in the Michaelis constant (K(M)). The behavior of alpha-CT in the hydrolysis of GPNA in DTAB solutions is at variance with that previously reported for the hydrolysis of 2-naphthyl acetate in solutions of the same surfactant (E. Abuin, E. Lissi, R. Duarte, Langmuir 19 (2003) 5374). An explanation of the different effects of the surfactant on the behavior of the enzyme with both substrates is advanced, taking into account the complexity of the mechanism of the alpha-CT-mediated reaction, more specifically, in terms of different rate-limiting steps for the formation of the measured products.
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Affiliation(s)
- Elsa Abuin
- Facultad de Química y Biología, Universidad de Santiago de Chile, Casilla 40, Correo 33, Santiago, Chile.
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Chen CW, Ou-Yang CC. Bounded water kinetic model of ?-galactosidase in reverse micelles. Bioprocess Biosyst Eng 2004; 26:307-13. [PMID: 15322894 DOI: 10.1007/s00449-004-0367-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
In the present investigation, beta-galactosidase was solubilized into Aerosol OT (AOT)/isooctane reverse micelles. Kinetic data for the hydrolysis of o-nitrophenyl-beta-D-galactopyranoside (ONPG) at different pH values and molar ratios of water to AOT (Wo) were collected. It was observed that the usual kinetic model used for beta-galactosidase catalysis in aqueous systems failed to represent the experimental data. A bounded water model, however, showed a better correlation between enzymatic activity and Wo. In contrast to the aqueous system, controlling the water concentration in the reverse micelles allows the rate constants for the reaction between water molecules and glycosyl-enzyme complexes to be evaluated.
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Affiliation(s)
- C Will Chen
- Department of Bioengineering, Tatung University, 40 Chungshan Road, 3rd Section, Taipei, Taiwan, Republic of China.
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20
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Luchter-Wasylewska E, Iciek M. Positive cooperativity in substrate binding of human prostatic acid phosphatase entrapped in AOT–isooctane–water reverse micelles. J Colloid Interface Sci 2004; 273:632-7. [PMID: 15082403 DOI: 10.1016/j.jcis.2004.01.075] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2003] [Accepted: 01/29/2004] [Indexed: 10/26/2022]
Abstract
The kinetics of 1-naphthyl phosphate and phenyl phosphate hydrolysis, catalyzed by human prostatic acid phosphatase (PAP) entrapped in AOT-isooctane-water reverse micelles, has been studied over surfactant hydration degree (w0) range 5 to 35. Continuous spectrophotometric acid phosphatase assays, previously prepared, were employed. PAP was catalytically active over the whole w0 studied range. In order to determine steady-state reaction constants the experimental data were fitted to Hill rate equation. Positive cooperativity in substrate binding was observed, as it was earlier found in aqueous solutions. The extent of cooperativity (expressed as the value of the Hill cooperation coefficient h) increased from 1 to 4, when the micellar water-pool size was growing, at fixed enzyme concentration. In the plots of catalytic activity (kcat) versus w0, the maxima have been found at w0=10 (pH 5.6) and 23 (pH 3.8). It is suggested that catalytically active monomeric and dimeric PAP forms are entrapped in reverse micelles of w0=10 and 23, respectively.
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Affiliation(s)
- Ewa Luchter-Wasylewska
- Institute of Medical Biochemistry, Jagiellonian University, Collegium Medicum, Kopernika 7, 31-034 Kraków, Poland.
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Viparelli P, Alfani F, Gallifuoco A, Cantarella M. Effect of quaternary ammonium salts on the hydrolysis of N-glutaryl-l-phenylalanine catalysed by α-chymotrypsin. ACTA ACUST UNITED AC 2004. [DOI: 10.1016/j.molcatb.2004.02.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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22
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Chen C, Ou-Yang CC, Yeh CW. Synthesis of galactooligosaccharides and transgalactosylation modeling in reverse micelles. Enzyme Microb Technol 2003. [DOI: 10.1016/s0141-0229(03)00155-8] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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23
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Effect of cationic and non-ionic surfactants on the hydrolysis of N-glutaryl-l-phenylalanine catalysed by chymotrypsin iso-enzymes. ACTA ACUST UNITED AC 2003. [DOI: 10.1016/s1381-1177(02)00125-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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24
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Marhuenda-Egea FC, Piera-Velázquez S, Cadenas C, Cadenas E. Reverse micelles in organic solvents: a medium for the biotechnological use of extreme halophilic enzymes at low salt concentration. ARCHAEA (VANCOUVER, B.C.) 2002; 1:105-11. [PMID: 15803648 PMCID: PMC2685557 DOI: 10.1155/2002/626457] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2001] [Accepted: 03/08/2002] [Indexed: 11/17/2022]
Abstract
Alkaline p-nitrophenylphosphate phosphatase (pNPPase) from the halophilic archaeobacterium Halobacterium salinarum (previously halobium) was solubilized at low salt concentration in reverse micelles of hexadecyltrimethyl-ammoniumbromide in cyclohexane with 1-butanol as co-surfactant. The enzyme maintained its catalytic properties under these conditions. The thermodynamic "solvation-stabilization hypothesis" has been used to explain the bell-shaped dependence of pNPPase activity on the water content of reverse micelles, in terms of protein-solvent interactions. According to this model, the stability of the folded protein depends on a network of hydrated ions associated with acidic residues at the protein surface. At low salt concentration and low water content (the ratio of water concentration to surfactant concentration; w0), the network of hydrated ions within the reverse micelles may involve the cationic heads of the surfactant. The bell-shaped profile of the relationship between enzyme activity and w0 varied depending on the concentrations of NaCl and Mn2+.
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Melo EP, Aires-Barros MR, Cabral JM. Reverse micelles and protein biotechnology. BIOTECHNOLOGY ANNUAL REVIEW 2002; 7:87-129. [PMID: 11686050 DOI: 10.1016/s1387-2656(01)07034-x] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Reverse micelles are nanometer-sized (1-10 nm) water droplets dispersed in organic media obtained by the action of surfactants. Surfactant molecules organize with the polar part to the inner side able to solubilize water and the apolar part in contact with the organic solvent. Proteins can be solubilized in the water pool of reverse micelles. Studies on the structure-function relationships of proteins in reverse micelles are very important since the microenvironment in which the protein is solubilized has physico-chemical properties distinct from a bulk aqueous solution. Some of the unique characteristics of reverse micelles make them very useful for biotechnological applications. Charge and hydrophilic/hydrophobic characteristics of the protein and the selection of surfactant can be used to achieve selective solubilization of proteins. This has been used to extend the classical liquid-liquid extraction with solvents to protein bioseparation. For biocatalysis the presence of a bulk organic solvent allow synthetic reactions to be performed via the control of water content and the solubilization of hydrophobic substrates. This is accomplished with a higher interfacial area (about 100 m2/mL) than the conventional biphasic systems, minimizing mass transfer problems.
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Affiliation(s)
- E P Melo
- Universidade do Algarve-F.E.R.N., Campus de Gambelas, 8000 Faro, Portugal.
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Krishna SH, Srinivas ND, Raghavarao KSMS, Karanth NG. Reverse micellar extraction for downstream processing of proteins/enzymes. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2002; 75:119-83. [PMID: 11787493 DOI: 10.1007/3-540-44604-4_5] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
New developments in the area of downstream processing are, hopefully, to fulfill the promises of modern biotechnology. The traditional separation processes such as chromatography or electrophoresis can become prohibitively expensive unless the product is of high value. Hence, there is a need to develop efficient and cost-effective downstream processing methods. Reverse micellar extraction is one such potential and a promising liquid-liquid extraction technique, which has received immense attention for isolation and purification of proteins/enzymes in the recent times. This technique is easy to scale-up and offers continuous operation. This review, besides briefly considering important physico-chemical and biological aspects, highlights the engineering aspects including mass transfer, mathematical modeling, and technology development. It also discusses recent developments in reverse micellar extraction such as affinity based separations, enzymatic reactions in reverse micelles coupled with membrane processes, reverse micellar extraction in hollow fibers, etc. Special emphasis has been given to some recent applications of this technique.
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Affiliation(s)
- S Hari Krishna
- Department of Fermentation Technology & Bioengineering, Central Food Technological Research Institute, Mysore, India.
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27
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Experimental validation of a model for α-chymotrypsin activity in aqueous solutions of surfactant aggregates. ACTA ACUST UNITED AC 2001. [DOI: 10.1016/s1381-1177(00)00250-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Aguilar LF, Abuin E, Lissi E. A Procedure for the Joint Evaluation of Substrate Partitioning and Kinetic Parameters for Reactions Catalyzed by Enzymes in Reverse Micellar Solutions. Arch Biochem Biophys 2001; 388:231-6. [PMID: 11368159 DOI: 10.1006/abbi.2001.2289] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A simple method useful for the joint evaluation of substrate partitioning and kinetic parameters for reactions catalyzed by enzymes entrapped in reverse micelles is proposed. The method is applied to the hydrolysis of 2-naphthyl acetate (2-NA) catalyzed by lipase in sodium 1,4-bis(2-ethylhexyl) sulfosuccinate (AOT)/buffer/heptane reverse micellar solutions. In the presence of micelles, the relationship between the initial reaction rate and the analytical concentration of 2-NA was dependent on AOT concentration at a constant W ([water]/[AOT]) value. The dependence of the initial reaction rate profiles with [AOT] was analyzed according with the method proposed to obtain the partition constant of 2-NA between the micelles and the external solvent, Kp. A value of Kp = 2.7 L mol(-1) was obtained irrespective of the water content of the micelles (W from 5 to 20). The catalytic rate constant kcat in the micellar solutions was independent of [AOT] but slightly decreased with an increase in W from 2 x 10(-6) mol g(-1) s(-1) at W = 5 to 1.2 x 10(-6) mol g(-1) s(-1) at W = 20. The apparent Michaelis constant determined in terms of the analytical concentration of 2-NA increased with [AOT] at a given W and moderately decreased with W at a fixed [AOT]. The increase with [AOT] is accounted for by considering the partitioning of the substrate. After correction for the partitioning of 2-NA values of (Km)corr were obtained as 3.9 x 10(-3) mol L(-1) (W = 5), 4.6 x 10(-3) mol L(-1) (W = 10), 2.3 x 10(-3) mol L(-1) (W = 15), and 1.7 x 10(-3) mol L(-1) (W = 20). The rate parameters in the aqueous phase in the absence of micelles, were obtained as (kcat)aq = 7.9 x 10(-6) mol g(-1) s(-1) and (Km)aq = 2.5 x 10(-3) mol L(-1). In order to compare the efficiency of the enzyme in the micellar solution with that in aqueous phase, the values of (Km)corr were in turn corrected to take into account differences in the substrate activity, obtaining so a set of (Km)*corr values. The efficiency of the enzyme in the micellar solution, defined as the ratio, kcat/(Km)*corr, was found to be higher than in the aqueous phase, even at high water contents (W = 20). This higher efficiency is due to a significant decrease in (Km)*corr values.
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Affiliation(s)
- L F Aguilar
- Facultad de Química y Biología, Universidad de Santiago de Chile.
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29
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Carvalho CM, Aires-Barros MR, Cabral JM. Kinetics of cutinase catalyzed transesterification in AOT reversed micelles: modeling of a batch stirred tank reactor. J Biotechnol 2000; 81:1-13. [PMID: 10936655 DOI: 10.1016/s0168-1656(00)00260-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A transesterification process is analyzed in its multiple kinetic components that include the determination of the kinetic constants for both substrates, butyl acetate (BAc) and hexanol (H), involved in the alcoholysis reaction and for the products formed (hexyl acetate (HAc) and butanol (B)), participating into the reverse reaction. The order of magnitude of these constants is discussed in relation with the AOT/isooctane reverse micellar system under study. The values of the equilibrium conversion (X(e)) and constant (K(eq)) were also determined. Diffusional limitations were detected for H concentrations lower than 450 mM and the correspondent effectiveness factors were calculated. Above 450 mM H the reaction is kinetically controlled. The operation of a batch stirred tank reactor (BSTR) was modeled considering the integrated rate equation for reversible kinetics.
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Affiliation(s)
- C M Carvalho
- Laboratorio de Engenharia Bioquimica, Instituto Superior Técnico, Centro de Engenharia Biológica e Química, Av. Rovisco Pais, 1049-001, Lisbon, Portugal
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30
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31
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Viparelli P, Alfani F, Cantarella M. Models for enzyme superactivity in aqueous solutions of surfactants. Biochem J 1999; 344 Pt 3:765-73. [PMID: 10585863 PMCID: PMC1220698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
Theoretical models are developed here for enzymic activity in the presence of direct micellar aggregates. An approach similar to that of Bru et al. [Bru, Sánchez-Ferrer and Garcia-Carmona (1989) Biochem. J. 259, 355-361] for reverse micelles has been adopted. The system is considered to consist of three pseudo-phases: free water, bound water and surfactant tails. The substrate concentration in each pseudo-phase is related to the total substrate concentration in the reaction medium. In the absence of interactions between the enzyme and the micelles, the model predicts either monotonically increasing or monotonically decreasing trends in the calculated reaction rate as a function of surfactant concentration. With enzyme-micelle interactions included in the formulation (by introducing an equilibrium relation between the enzyme confined in the free water and in the bound water pseudo-phases, and by allowing for different catalytic behaviours for the two forms), the calculated reaction rate can exhibit a bell-shaped dependence on surfactant concentration. The effect of the partition of enzyme and substrate is described, as is that of enzyme efficiency in the various pseudo-phases.
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Affiliation(s)
- P Viparelli
- Dipartimento di Chimica, Ingegneria Chimica e Materiali, Università di L'Aquila, Monteluco di Roio, 67100 L'Aquila, Italia
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32
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Abstract
Water-in-oil microemulsions, or reverse micelles, are being evaluated as a reaction medium for a variety of enzymatic reactions. These systems have many potential biotechnological applications. Important examples are the use of various lipase microemulsion systems for hydrolytic or synthetic reactions. This review illustrates the biotechnological applications of microemulsions as media for bioorganic reactions. The principal focus is on lipase catalyzed processes.
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Affiliation(s)
- H Stamatis
- Institute of Biological Research and Biotechnology, National Hellenic Research Foundation, 48, Vas. Constantinou Avenue, 11635 Athens, Greece
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34
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Fadnavis NW, Babu RL, Deshpande A. Reactivity of trypsin in reverse micelles: pH-effects on the W0 versus enzyme activity profiles. Biochimie 1998; 80:1025-30. [PMID: 9924980 DOI: 10.1016/s0300-9084(99)80007-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
pH-Dependence of hydrolytic activity of trypsin has been studied in cationic reverse micellar system of cetyltrimethylammonium bromide (CTAB) in (50% v/v) chloroform/isooctane using a positively charged substrate N(alpha)-benzoyl-L-arginine ethyl ester (BAEE). The pH of the medium was varied from 4.0 to 8.5 with addition of 0.025 M citrate-phosphate buffer containing 1 mM CaCl2. Optimum pH for maximum enzyme activity, pH(opt) in reverse micelles is found to be similar to that observed in bulk aqueous solution (8.0-8.5). However, changes in activity of trypsin (k(cat)) as a function of water content W0 (W0 = [H2O]/[CTAB]) in reverse micelles are found to be pH dependent. At low pH (4.0) and low water content (W0 = 5) the enzyme is more active in reverse micelles than in bulk aqueous solution by a factor of 2. This 'superactivity' is lost at higher W0 values and the k(cat) in reverse micelles is found to be similar to that observed in aqueous bulk. At pH 5, the enzyme activity is found to be independent of W0 while at pH 6.0-6.5 the enzyme activity is low at W0 5 and increases with water content to a constant value which is still 50% lower than that in aqueous buffer. Above pH 7, the W0-activity profile becomes distinctly bell shaped with W0 optimum around 10-15. The enzyme activity at optimum W0 is close to that observed in aqueous bulk.
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Affiliation(s)
- N W Fadnavis
- Biotransformations Laboratory, Discovery Block, Indian Institute of Chemical Technology, Tarnaka, Hyderabad, India
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35
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Willard DM, Riter RE, Levinger NE. Dynamics of Polar Solvation in Lecithin/Water/Cyclohexane Reverse Micelles. J Am Chem Soc 1998. [DOI: 10.1021/ja980086k] [Citation(s) in RCA: 202] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Dale M. Willard
- Contribution from the Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872
| | - Ruth E. Riter
- Contribution from the Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872
| | - Nancy E. Levinger
- Contribution from the Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872
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36
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Abstract
Water is fundamental for enzyme action and for formation of the three-dimensional structure of proteins. Hence, it may be assumed that studies on the interplay between water and enzymes can yield insight into enzyme function and formation. This has proven correct, because the numerous studies that have been made on the behavior of water-soluble and membrane enzymes in systems with a low water content (reverse micelles or enzymes suspended in nonpolar organic solvents) have revealed properties of enzymes that are not easily appreciated in aqueous solutions. In the low water systems, it has been possible to probe the relation between solvent and enzyme kinetics, as well as some of the factors that affect enzyme thermostability and catalysis. Furthermore, the studies show that low water environments can be used to stabilize conformers that exhibit unsuspected catalytic properties, as well as intermediates of enzyme function and formation that in aqueous media have relatively short life-times. The structure of enzymes in these unnatural conditions is actively being explored.
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37
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Svensson M, Rees GD, Robinson BH, Stephenson G. Phospholipid-stabilised water-in-oil microemulsions: A study of ester synthesis by Humicola lanuginosa lipase. Colloids Surf B Biointerfaces 1996. [DOI: 10.1016/s0927-7765(96)01311-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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38
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Tang SS, Chang GG. Kinetic mechanism of octopus hepatopancreatic glutathione transferase in reverse micelles. Biochem J 1996; 315 ( Pt 2):599-606. [PMID: 8615835 PMCID: PMC1217238 DOI: 10.1042/bj3150599] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Octopus glutathione transferase (GST) was enzymically active in aerosol-OT [sodium bis-(2-ethylhexyl)sulphosuccinate]/iso-octane reverse micelles albeit with lowered catalytic constant (kcat). The enzyme reaction rate was found to be dependent on the [H2O]/[surfactant] ratio (omega(o)) of the system with maximum rate observed at omega(o) 13.88, which corresponded to vesicles with a core volume of 64 nm3. According to the physical examinations, a vesicle of this size is barely large enough to accommodate a monomeric enzyme subunit. Dissociation of the enzyme in reverse micelles was confirmed by cross-linking of the associated subunits with glutaraldehyde and separation of the monomers and dimers with electrophoresis in the presence of SDS. The kinetic properties of the enzyme were investigated by steady-state kinetic analysis. Both GSH and 1-chloro-2,4-dinitrobenzene (CDNB) showed substrate inhibition and the Michaelis constant for CDNB was increased by 36-fold to 11.05 mM in reverse micelles. Results on the initial-velocity and product-inhibition studies indicate that the octopus GST conforms to a steady-state sequential random Bi Bi mechanism. The results from a log kcat versus pH plot suggest that amino acid residues with pKa values of 6.56 0.07 and 8.81 0.17 should be deprotonated to give optimum catalytic function. In contrast, the amino acid residue with a pKa value of 9.69 0.16 in aqueous solution had to be protonated for the reaction to proceed. We propose that the pKa1 (6.56) is that for the enzyme-bound GSH, which has a pKa value lowered by 1.40-1.54 pH units compared with that of free GSH in reverse micelles. The most probable candidate for the observed pKa2 (8.81) is Tyr7 of GST. The pKa of Tyr7 is 0.88 pH unit lower than that in aqueous solution and is about 2 pH units below the normal tyrosine. This tyrosyl residue may act as a base catalyst facilitating the dissociation of enzyme-bound GSH. The possible interaction of GST with plasma membrane in vivo is discussed.
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Affiliation(s)
- S S Tang
- Graduate Institutes of Life Sciences and Biochemistry, National Defence Medical Centre, Taipei, Taiwan, Republic of China
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39
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Crooks GE, Rees GD, Robinson BH, Svensson M, Stephenson GR. Comparison of hydrolysis and esterification behavior ofHumicola lanuginosa andRhizomucor miehei lipases in AOT-stabilized water-in-oil microemulsions: I. Effect of pH and water content on reaction kinetics. Biotechnol Bioeng 1995; 48:78-88. [DOI: 10.1002/bit.260480111] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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40
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Affiliation(s)
- R Bru
- Departamento de Bioquímica y Biología Molecular A, Universidad de Murcia, Spain
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41
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Yang F, Russell AJ. A comparison of lipase-catalyzed ester hydrolysis in reverse micelles, organic solvents, and biphasic systems. Biotechnol Bioeng 1995; 47:60-70. [DOI: 10.1002/bit.260470108] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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42
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Kunugi S, Hayashi Y, Koyasu A, Tanaka N, Shiraishi M. Enzyme Reactions in Microstructured Media. Subtilisin Catalysis in Alkyl Glucopyranosides Aggregates. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 1995. [DOI: 10.1246/bcsj.68.1012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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43
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Otero C, Rúa ML, Robledo L. Influence of the hydrophobicity of lipase isoenzymes from Candida rugosa on its hydrolytic activity in reverse micelles. FEBS Lett 1995; 360:202-6. [PMID: 7875331 DOI: 10.1016/0014-5793(95)00104-h] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
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 alpha-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 omega 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 omega 0 is reported. The different interaction of isolipases A and B with the micellar system produced an opposite omega 0 dependence to their stabilities. The more hydrophobic lipase A had higher stability at higher droplet sizes.
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Affiliation(s)
- C Otero
- Instituto de Catálisis, CSIC, Cantoblanco, Madrid, Spain
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44
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Stamatis H, Xenakis A, Dimitriadis E, Kolisis FN. Catalytic behavior ofPseudomonas cepacia lipase in w/o microemulsions. Biotechnol Bioeng 1995; 45:33-41. [DOI: 10.1002/bit.260450106] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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45
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Enzyme reactions in reverse micelles. ACTA ACUST UNITED AC 1995. [DOI: 10.1016/s0167-4501(06)80154-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
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46
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Gupta S, Mukhopadhyay L, Moulik S. Kinetics in microemulsion medium 2. Hydrolysis of p-nitrophenyl phosphate with alkaline phosphatase in w/o microemulsion medium using the surfactant AOT. Colloids Surf B Biointerfaces 1994. [DOI: 10.1016/0927-7765(94)01127-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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47
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Sarcar S, Munshi N, Jain TK, Maitra A. The effect of droplet dynamics on the enzyme kinetic reactions by yeast alcohol dehydrogenase in reverse micelles. Colloids Surf A Physicochem Eng Asp 1994. [DOI: 10.1016/0927-7757(94)02777-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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48
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Sánchez-Ferrer A, García-Carmona F. Biocatalysis in reverse self-assembling structures: reverse micelles and reverse vesicles. Enzyme Microb Technol 1994; 16:409-15. [PMID: 7764793 DOI: 10.1016/0141-0229(94)90156-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The use of two reverse self-assembling systems, such as reverse micelles and reverse vesicles, to model the enzymatic function of biological membranes is discussed. They permit direct measurement of enzyme kinetics since these ternary systems form optically transparent solutions. The physicochemical characteristics of both systems are differentiated since they clearly affect enzyme behavior. The four enzymatic profiles that have been described in reverse micelles as a function of micelle size (omega 0) and the kinetic models developed to explain them are discussed. Reverse vesicles, first described in 1991, are also presented as a new system that shares properties with reverse micelles and liposomes, and in which enzymes show unexpected behavior. Finally, the potential use of these systems in protein extraction, hydrophobic protein stabilization, and biotechnology are noted, although a better physicochemical characterization is needed in order to explore their full potential.
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Affiliation(s)
- A Sánchez-Ferrer
- Departamento de Bioquímica, Facultad de Biología, Universidad de Murcia, Spain
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49
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Komives CF, Lilley E, Russell AJ. Biodegradation of pesticides in nonionic water-in-oil microemulsions of tween 85: Relationship between micelle structure and activity. Biotechnol Bioeng 1994; 43:946-59. [DOI: 10.1002/bit.260431008] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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50
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Miyake Y, Owari T, Ishiga F, Teramoto M. Enzymatic reaction in water-in-oil microemulsions. Part 2.—Rate of hydrolysis of a hydrophobic substrate, 2-naphthyl acetate. ACTA ACUST UNITED AC 1994. [DOI: 10.1039/ft9949000979] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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