1
|
Abstract
Enzymes in aqueous environment usually deal with purified enzyme preparations isolated from living matter which does not mimic real catalytic properties in vivo. Interaction of enzymes in nature takes place with different surfaces composed from lipid membranes or they get incorporated into biomembranes. Although Water is not a dominating component in the cytoplasm but plays a structural role by participating in the formation of biocatalytic complexes like glycoproteins. Water is needed to keep biocatalyst in active confirmation and hence plays very crucial role in biocatalytic reactions, activity and stability so that it can be used for various applications. This review focuses on composition, preparation properties and parameters which influence enzymes in reverse micelles and application of micellar enzymology to study protein chemistry, shifting equilibrium of various reactions, to recover various products by partition chromatography and bioremediation of chlorophenolic environmental pollutants.
Collapse
|
2
|
Arora B, Mukherjee J, Gupta MN. Enzyme promiscuity: using the dark side of enzyme specificity in white biotechnology. ACTA ACUST UNITED AC 2014. [DOI: 10.1186/s40508-014-0025-y] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Abstract
Enzyme promiscuity can be classified into substrate promiscuity, condition promiscuity and catalytic promiscuity. Enzyme promiscuity results in far larger ranges of organic compounds which can be obtained by biocatalysis. While early examples mostly involved use of lipases, more recent literature shows that catalytic promiscuity occurs more widely and many other classes of enzymes can be used to obtain diverse kinds of molecules. This is of immense relevance in the context of white biotechnology as enzyme catalysed reactions use greener conditions.
Collapse
|
3
|
Hanley AB, Grinfeld E, Baxter RL. The Cleavage of Nucleic Acids in Reversed Micelles Using Site Specific Endonucleases. ACTA ACUST UNITED AC 2009. [DOI: 10.3109/10242429008992068] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- A. Bryan Hanley
- AFRC Institute of Food Research, Norwich Laboratory, Colney Lane, Norwich, UK
| | - Esther Grinfeld
- Department of Chemistry, University of Edinburgh, West Mains Road, Edinburgh, UK
| | - Robert L. Baxter
- Department of Chemistry, University of Edinburgh, West Mains Road, Edinburgh, UK
| |
Collapse
|
4
|
Azevedo AM, Fonseca LP, Graham DL, Cabral JMS, Prazeres DMF. BEHAVIOUR OF HORSERADISH PEROXIDASE IN AOT REVERSED MICELLES. BIOCATAL BIOTRANSFOR 2009. [DOI: 10.3109/10242420109105265] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
5
|
Vagin MY, Trashin SA, Karpachova GP, Klyachko NL, Karyakin AA. Protein extracting electrodes: Insights in the mechanism. J Electroanal Chem (Lausanne) 2008. [DOI: 10.1016/j.jelechem.2008.06.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
6
|
PATEL MAYANKT, NAGARAJAN R, KILARA ARUN. LIPASE-CATALYZED BIOCHEMICAL REACTIONS IN NOVEL MEDIA: A REVIEW. CHEM ENG COMMUN 2007. [DOI: 10.1080/00986449608936574] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- MAYANK T. PATEL
- a The Pennsylvania State University , University Park , PA , 16802
| | - R. NAGARAJAN
- a The Pennsylvania State University , University Park , PA , 16802
| | - ARUN KILARA
- a The Pennsylvania State University , University Park , PA , 16802
| |
Collapse
|
7
|
Kumar A, Morén AK, Holmberg HK. Synthesis of a Macrocyclic Lactone. II. Reaction in Microheterogeneous Media. J DISPER SCI TECHNOL 2007. [DOI: 10.1081/dis-120017947] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Anil Kumar
- a Department of Applied Surface Chemistry , Chalmers University of Technology , SE‐412 96 , Göteborg , Sweden
| | - Anna Karin Morén
- a Department of Applied Surface Chemistry , Chalmers University of Technology , SE‐412 96 , Göteborg , Sweden
- b ACO HUD AB , Upplands , Väsby , Sweden
| | - H. Krister Holmberg
- a Department of Applied Surface Chemistry , Chalmers University of Technology , SE‐412 96 , Göteborg , Sweden
| |
Collapse
|
8
|
Vagin MY, Trashin SA, Ozkan SZ, Karpachova GP, Karyakin AA. Electroactivity of redox-inactive proteins at liquid|liquid interface. J Electroanal Chem (Lausanne) 2005. [DOI: 10.1016/j.jelechem.2005.06.020] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
9
|
Bauduin P, Touraud D, Kunz W. Design of low-toxic and temperature-sensitive anionic microemulsions using short propyleneglycol alkyl ethers as cosurfactants. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2005; 21:8138-45. [PMID: 16114914 DOI: 10.1021/la0509652] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The phase behavior of anionic microemulsions composed of water, sodium dodecyl sulfate (SDS), dodecane, and short propyleneglycol monoalkyl ethers (C(n)()PO(m)(); n = 3, m = 1 and n = 4, m = 2, 3) is studied. From the pseudoternary phase diagrams, it is inferred that C(n)()PO(m)() compounds have cosurfactant behaviors comparable to those of 1-butanol and 1-pentanol, which are the most efficient and widely used cosurfactants. In contrast to these alcohols, the C(n)()PO(m)() cosurfactants induce high temperature dependences in the SDS microemulsion systems. Furthermore, SDS/C(n)()PO(m)() microemulsions can be formed with small SDS concentrations (SDS/C(4)PO(3) mass ratio of 1/6.26). These have a low toxicity in contrast to systems containing genotoxic short ethyleneglycol ethers (C(n)()EO(m)()) as the cosurfactant. The strong temperature dependence can be favorable in the recovery of reaction products when the microemulsion is used either as a reaction medium or in extraction processes.
Collapse
Affiliation(s)
- Pierre Bauduin
- Institute of Physical and Theoretical Chemistry, University of Regensburg, D-93040 Regensburg, Germany
| | | | | |
Collapse
|
10
|
Surfactant modified enzymes: Solubility and activity of surfactant-modified catalase in organic solvents. Enzyme Microb Technol 1997. [DOI: 10.1016/s0141-0229(96)00086-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
11
|
Karyakin AA, Karyakina EE, Gorton L, Bobrova OA, Lukachova LV, Gladilin AK, Levashov AV. Improvement of Electrochemical Biosensors Using Enzyme Immobilization from Water−Organic Mixtures with a High Content of Organic Solvent. Anal Chem 1996. [DOI: 10.1021/ac960397i] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
12
|
Carreto ML, Rubio S, Pérez-Bendito D. Organic microheterogeneous systems in kinetic analysis. Self-assembled systems. A review. Analyst 1996. [DOI: 10.1039/an996210033r] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
13
|
Murakata T, Yusa K, Yada M, Kato Y, Sato S. Esterification activity of lipase entrapped in reverse micelles formed in liquefied gas. JOURNAL OF CHEMICAL ENGINEERING OF JAPAN 1996. [DOI: 10.1252/jcej.29.277] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Kazuhisa Yusa
- Department of Material Science and Engineering, Yamagata University
| | - Manabu Yada
- Department of Material Science and Engineering, Yamagata University
| | - Yosihiro Kato
- Department of Material Science and Engineering, Yamagata University
| | - Shimio Sato
- Department of Material Science and Engineering, Yamagata University
| |
Collapse
|
14
|
Ping Xiao H, Yi Li Z, Ward OP. Hydrolysis of ethyl mandelate and esterification of 2-bromopropionic acid in micro-emulsions. J Ind Microbiol Biotechnol 1995. [DOI: 10.1007/bf01569960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
15
|
Affiliation(s)
- A V Levashov
- Department of Chemistry, Moscow State University, Russia
| | | |
Collapse
|
16
|
Abstract
Although they were used historically as antimicrobial agents, there is a modern requirement to devise organic solvent systems for exploitation in the biotransformation by intact cells of substrates that are poorly soluble in water. Water-immiscible solvents are normally less cytotoxic than are water-miscible ones. While a unitary mechanism is excluded, damage to the membrane remains the likeliest major mechanism of cytotoxicity, and may be conveniently assessed using an electronic biomass probe. Studies designed to account for the mechanisms of action of general anesthetics and of uncouplers parallel those designed to account for the cytotoxicity of organic solvents. Although there are hundreds of potential physical descriptors of solvent properties, many are broadly similar to each other, such that the intrinsic dimensionality of solvent space is relatively small (< 10). This opens up the possibility of providing a rational biophysical basis for the optimization of the solvents used for biotransformations. The widely used descriptor of solvent behavior, log P (the octanol:water partition coefficient), is a composite of more fundamental molecular descriptors; this explains why there are rarely good correlations between cytotoxicity and log P when a wide variety of solvents is studied. Although the intrinsic dimensionality of solvent space is relatively small, pure solvents still populate it rather sparsely. Thus, mixtures of solvents can and do provide the opportunity of obtaining a solvent optimal for a biotransformation of interest.
Collapse
Affiliation(s)
- G J Salter
- Institute of Biological Sciences, University of Wales, Aberystwyth, Dyfed, U.K
| | | |
Collapse
|
17
|
O'Connor CJ, Cleverly DR. Fourier-transform infrared assay of bile salt-stimulated lipase activity in reversed micelles. JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY (OXFORD, OXFORDSHIRE : 1986) 1994; 61:209-214. [PMID: 7527225 DOI: 10.1002/jctb.280610305] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
A Fourier-transform infrared (FT-IR) spectroscopic method has been developed for assaying the bile salt-stimulated human milk lipase (BSSL, EC3.1) catalyzed hydrolysis of triolein in AOT reversed micelles in iso-octane. At 37 degrees C in 50 mmol dm-3 AOT the molar absorbtivities for the carbonyl stretching frequencies for triolein (at 1751 cm-1) and oleic acid (at 1714 cm-1) were 1646 dm3 mol-1 cm-1 and 743 dm3 mol-1 cm-1, respectively. The rate was linearly dependent upon the concentration of enzyme in the water pool up to 10 mg cm-3 and maximum activity was observed at a ratio (w0) of [H2O]:[AOT] = 16.7. Using these conditions, and in the presence of 10 mmol dm-3 sodium taurocholate (TC), the derived Michaelis-Menten parameters Vmax and Km were 57.5 mumol min-1 mg-1 and 5.53 mmol dm-3, respectively. These results are compared with those obtained in an oil-in-water microemulsion system and are discussed in terms of the relative partitioning of the enzyme and the substrate in the aqueous and oil phases and the interfacial concentration of the substrate in the two systems.
Collapse
Affiliation(s)
- C J O'Connor
- Department of Chemistry, University of Auckland, New Zealand
| | | |
Collapse
|
18
|
Kommareddi NS, McPherson GL, John VT. The use of EPR spectroscopy under non-ambient conditions to characterize the consequences of clathrate hydrate formation in water-in-oil microemulsions. Colloids Surf A Physicochem Eng Asp 1994. [DOI: 10.1016/0927-7757(94)02965-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
19
|
|
20
|
Kommareddi NS, O'Connor KC, John VT. EPR characterizations of ?-chymotrypsin active site dynamics in reversed micelles at enhanced gas pressures and after subjection to clathrate formation conditions. Biotechnol Bioeng 1994; 43:215-24. [DOI: 10.1002/bit.260430305] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
21
|
Mojović L, Šiler-Marinković S, Kukić G, Vunjak-Novaković G. Rhizopus arrhizus lipase-catalyzed interesterification of the midfraction of palm oil to a cocoa butter equivalent fat. Enzyme Microb Technol 1993. [DOI: 10.1016/0141-0229(93)90132-l] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
22
|
Temperature, pH and Media Influence on Lipase Stability. ACTA ACUST UNITED AC 1993. [DOI: 10.1016/b978-0-444-89372-7.50058-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
|
23
|
Borzeix F, Monot F, Vandescasteele JP. Strategies for enzymatic esterification in organic solvents: Comparison of microaqueous, biphasic, and micellar systems. Enzyme Microb Technol 1992; 14:791-7. [PMID: 1368967 DOI: 10.1016/0141-0229(92)90094-5] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The kinetics of butyl butyrate synthesis by a lipase from Mucor miehei in different types of organic media were investigated. The three systems studied were a microaqueous medium containing enzyme in suspension in hexane, a water-hexane two-phase system, and reverse micelles. The synthesis of butyl butyrate was possible in all cases because of a favorable partition of the ester into the organic solvent. A sufficient stirring rate was necessary to achieve good reaction rates in the case of the liquid-liquid biphasic medium. The effect of water content was different according to the type of system used. The dependence of reaction rate and of conversion yield on enzyme and substrate concentrations was also investigated. From an applied point of view, the best performances were obtained with either microaqueous or liquid-liquid two-phase systems. The use of reverse micelles can be advocated only in particular conditions, such as low enzyme concentration, compatible with the specific constraints it involves.
Collapse
Affiliation(s)
- F Borzeix
- Institut Français du Pétrole, Division Biotechnologie et Environnement, Rueil-Malmaison, France
| | | | | |
Collapse
|
24
|
Bismuto E, Sirangelo I, Irace G. Fluorescence lifetime distribution of 1,8-anilinonaphthalenesulfonate (ANS) in reversed micelles detected by frequency domain fluorometry. Biophys Chem 1992; 44:83-90. [PMID: 1391609 DOI: 10.1016/0301-4622(92)85040-b] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The fluorescence emission decay of ANS (1,8-anilinonaphthalenesulfonate) in reversed AOT (sodium bis-(2-ethyl-1-hexy)sulfosuccinate) micelles at different water contents was investigated by frequency domain fluorometry. The whole ANS emission decay in reversed AOT micelles could not be fitted in terms of discrete lifetime values, i.e., mono-exponential and bi-exponential models. Better fits were obtained when using continuous unimodal Lorentzian lifetime distributions. This was interpreted as arising from the reorientation processes of water molecules around the excited state of ANS or probe exchange among different probe locations, occurring on a time scale longer than fluorophore lifetime. The dependence of ANS fluorescence anisotropy on the emission wavelength was consistent with the existence of a great emission heterogeneity especially for inverted micelles having reduced H2O/AOT molar ratio. Finally, the observation that the distribution width decreases with increasing temperature and/or micelle size suggested that fast processes of water dipolar reorganization around the fluorophore are facilitated under these conditions.
Collapse
Affiliation(s)
- E Bismuto
- Dipartimento di Biochimica e Biofisica, Università di Napoli, Italy
| | | | | |
Collapse
|
25
|
Abstract
Enzyme catalysis in organic solvents is being increasingly used for a variety of applications. Of special interest are the cases in which the medium is predominantly non-aqueous and contains little water. A display of enzyme activity, even in anhydrous solvents (water less than 0.02% by vol.), perhaps reflects that the minimum necessity for water is for forming bonds with polar amino acids on the enzyme surface. The rigidity of enzyme structure at such low water content results in novel substrate specificities, pH memory and the possibility of techniques such as molecular imprinting. Limited data indicates that, while enhanced thermal stability invariably results, the optimum temperature for catalysis may not change. If true in general, this enhanced thermostability would have extremely limited benefits. Medium engineering and biocatalyst engineering are relevant techniques to improve the efficiency and stability of enzymes in such low water systems. Most promising, as part of the latter, is the technique of protein engineering. Finally, this review provides illustrations of applications of such systems in the diverse areas of organic synthesis, analysis and polymer chemistry.
Collapse
Affiliation(s)
- M N Gupta
- Chemistry Department, Indian Institute of Technology, Delhi
| |
Collapse
|
26
|
Hanley AB, Furniss CS, Kwiatkowska CA, Mackie AR. The manipulation of DNA with restriction enzymes in low water systems. BIOCHIMICA ET BIOPHYSICA ACTA 1991; 1074:40-4. [PMID: 1710498 DOI: 10.1016/0304-4165(91)90036-g] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The cleavage of phage lambda (lambda) DNA by the restriction enzyme HindIII in low water systems has been investigated. Two types of low water systems have been studied--those which contain a surfactant in a reverse micelle environment and a surfactant-free system in which a solid support (celite) is used. The effect of the surfactants themselves in a normal aqueous environment has also been studied. Charged surfactants were found to greatly inhibit HindIII activity in aqueous buffer, while non-ionic surfactants did not affect either the activity or the specificity of the restriction enzyme. The rate of cleavage by HindIII in a reverse micelle system consisting of sodium dioctylsulphosuccinate is very slow, however, in a Triton B system the expected fragments are observed. In a surfactant-free low water environment, cleavage occurs at the expected sites but in a different order to that observed in normal aqueous systems. These results suggest that DNA tertiary structure in low water systems is different to that in aqueous solution and that this influences cleavage by the restriction enzyme HindIII.
Collapse
Affiliation(s)
- A B Hanley
- A.F.R.C. Institute of Food Research, Norwich, U.K
| | | | | | | |
Collapse
|
27
|
|
28
|
Bona M, Fabian M, Sedlák M. Spectral and catalytic properties of cytochrome oxidase in organic solvents. BIOCHIMICA ET BIOPHYSICA ACTA 1990; 1020:94-100. [PMID: 2171645 DOI: 10.1016/0005-2728(90)90098-o] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Isolated bovine heart cytochrome oxidase has been extracted into n-hexane, probably in reverse micelles, by the use of asolectin and calcium. The diluted extracts are composed of particles with the hydrodynamic radius of 42 nm. Spectral characteristics of the extracted oxidase are similar to those in aqueous solutions. At the high molar ratio of water to phospholipid (W0 = 8) in an organic solvent both cytochrome a and a3 are reducible and oxygen uptake is observed. However, at low W0 (W0 = 1.8) the rate of cytochrome a reduction is decreased and reduction of cytochrome a3 is inhibited.
Collapse
Affiliation(s)
- M Bona
- Institute of Experimental Physics, Slovak Academy of Sciences, Kosice, Czechoslovakia
| | | | | |
Collapse
|
29
|
Larsson KM, Adlercreutz P, Mattiasson B, Olsson U. Enzymatic catalysis in microemulsions: Enzyme reuse and product recovery. Biotechnol Bioeng 1990; 36:135-41. [DOI: 10.1002/bit.260360205] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
30
|
|
31
|
Wolbert RB, Hilhorst R, Voskuilen G, Nachtegaal H, Dekker M, Van't Riet K, Bijsterbosch BH. Protein transfer from an aqueous phase into reversed micelles. The effect of protein size and charge distribution. EUROPEAN JOURNAL OF BIOCHEMISTRY 1989; 184:627-33. [PMID: 2806246 DOI: 10.1111/j.1432-1033.1989.tb15059.x] [Citation(s) in RCA: 95] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Proteins are spontaneously transferred from an aqueous solution into reversed micelles, provided the aqueous phase has the proper composition. Besides the composition of the aqueous phase, the composition of the organic phase and the properties of the proteins also play a role. We studied uptake profiles of 19 proteins as a function of pH of the aqueous solution. The organic phase consisted of trioctylmethylammonium chloride and nonylphenol pentaethoxylate (Rewopal HV5) as surfactant, octanol as cosurfactant and isooctane as continuous phase. In all cases, except for rubredoxin, proteins were transferred at pH values above their isoelectric point. The pH where maximal solubilization takes place can be described by the relationship: pHoptimum = isoelectric point +0.11 x 10(-3) Mr -0.97. So, the larger the protein, the more charge is needed to provide the energy required for the adaptation of the micellar size to the protein size. For protein transfer into sodium di-(2-ethylhexyl)sulphosuccinate (AOT) reversed micelles a similar relationship was found. The percentage of protein transferred could be related to the symmetry of charge distribution over the protein. This symmetry was expressed as the % of random electric moments on a protein that is larger than the effective electric moment of the protein (% S) [Barlow, D. J. and Thornton, J. M. (1986) Biopolymers 25, 1717]. The larger the value of % S, the more homogeneously the charges are distributed and the lower the percentage transfer.
Collapse
Affiliation(s)
- R B Wolbert
- Department of Biochemistry, Agricultural University, Wageningen, The Netherlands
| | | | | | | | | | | | | |
Collapse
|
32
|
Larsson KM, Oldfield C, Freedman RB. Analysis of the inactivation of liver alcohol dehydrogenase during storage in Aerosol-OT/isooctane microemulsions. EUROPEAN JOURNAL OF BIOCHEMISTRY 1989; 183:357-61. [PMID: 2474442 DOI: 10.1111/j.1432-1033.1989.tb14936.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Changes in the enzymatic properties of horse liver alcohol dehydrogenase (HLADH; EC 1.1.1.1) were studied as a function of incubation time in Aerosol-OT/isooctane microemulsions. The enzyme was characterized by fluorimetric binding studies of the inhibitor isobutyramide to the binary complex, HLADH-NADH and by determination of Km,app and Vmax,app values for cyclohexanone. The Km,app values for cyclohexanone and the Kd,app for isobutyramide stay constant throughout a 48-h incubation, whereas the Vmax,app and the total number of inhibitor binding sites decrease. Thus the inactivation process previously described corresponds to progressive loss of functional sites, while the properties of the remaining functional sites are unchanged. If no co-enzyme is added to the system, the enzyme loses catalytic activity within less than an hour, but if co-enzyme is added, a fraction of the HLADH enzyme population retains enzyme activity over a long period of time. Hence the presence of bound co-enzyme significantly inhibits the process(es) leading to inactivation of the enzyme in the microemulsions.
Collapse
Affiliation(s)
- K M Larsson
- Department of Biotechnology, Chemical Center, University of Lund, Sweden
| | | | | |
Collapse
|
33
|
Martinek K, Klyachko NL, Kabanov AV, Khmelnitsky YuL, Levashov AV. The second E.C. Slater lecture. Micellar enzymology: its relation to membranology. BIOCHIMICA ET BIOPHYSICA ACTA 1989; 981:161-72. [PMID: 2659086 DOI: 10.1016/0005-2736(89)90024-2] [Citation(s) in RCA: 241] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Micellar enzymology, a new trend in molecular biology, studies catalysis by enzymes entrapped in hydrated reversed micelles composed of surfactants (phospholipids, detergents) in organic solvents. The key research problems of micellar enzymology and its relation to enzyme membranology are discussed.
Collapse
Affiliation(s)
- K Martinek
- Institute of Organic Chemistry and Biochemistry, Czechoslovak Academy of Sciences, Prague
| | | | | | | | | |
Collapse
|
34
|
Khmelnitsky Y, Levashov A, Klyachko N, Martinek K. Engineering biocatalytic systems in organic media with low water content. Enzyme Microb Technol 1988. [DOI: 10.1016/0141-0229(88)90115-9] [Citation(s) in RCA: 261] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
35
|
Abstract
Biocatalysis in nonaqueous media is being used in increasing regularity both in academic and industrial research. A variety of biocatalysts have been used in organic media including enzymes, multi-enzyme systems, and whole cells. In addition, the nonaqueous media has encompassed both monophasic and biphasic solvent systems, enzymes and whole cells in reversed micelles, enzymes and cells in nearly anhydrous (no added water) solvents, and enzymes catalytically active in supercritical fluids and the gas phase. Recent US and overseas patents and scientific literature on biocatalysis in nonaqueous media are surveyed. Patent abstracts are summarized individually, and literature references are divided into major subheadings.
Collapse
Affiliation(s)
- J S Dordick
- Department of Chemical and Materials Engineering, University of Iowa, Iowa City 52242
| |
Collapse
|
36
|
Khmelnitsky YL, Hilhorst R, Veeger C. Detergentless microemulsions as media for enzymatic reactions. Cholesterol oxidation catalyzed by cholesterol oxidase. EUROPEAN JOURNAL OF BIOCHEMISTRY 1988; 176:265-71. [PMID: 3166425 DOI: 10.1111/j.1432-1033.1988.tb14277.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Catalytic activity and stability of cholesterol oxidase dissolved in ternary systems composed of n-hexane, isopropanol, and water were studied. The dependence of catalytic activity on the composition of the system revealed two maxima, in contrast to the behaviour of previously studied enzymes where a single maximum has been observed. The stability profile of cholesterol oxidase showed a single sharp maximum coinciding with the microemulsion region of the phase diagram. Both catalytic activity and the first-order inactivation rate constant of cholesterol oxidase dissolved in n-hexane/isopropanol/water ternary systems were found to decrease with decreasing temperature. This decrease was more rapid for the inactivation rate constant than for catalytic activity, the activation energies being 200 and 60 kJ.mol-1, respectively. Preparative conversion of cholesterol to cholestenone catalyzed by cholesterol oxidase in n-hexane/isopropanol/water ternary systems was carried out with 100% yield. Decreased temperature and the presence of catalase were required to achieve high degrees of cholesterol conversion. A simple procedure suitable for rapid separation of the reaction product and recovery of the enzyme was developed.
Collapse
Affiliation(s)
- Y L Khmelnitsky
- Department of Biochemistry, Agricultural University, Wageningen
| | | | | |
Collapse
|
37
|
Enzymes entrapped in reversed micelles of surfactants in organic solvents: A theoretical treatment of the catalytic activity regulation. J Theor Biol 1988. [DOI: 10.1016/s0022-5193(88)80325-4] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
38
|
|