1
|
Dupont J, Leal BC, Lozano P, Monteiro AL, Migowski P, Scholten JD. Ionic Liquids in Metal, Photo-, Electro-, and (Bio) Catalysis. Chem Rev 2024; 124:5227-5420. [PMID: 38661578 DOI: 10.1021/acs.chemrev.3c00379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Ionic liquids (ILs) have unique physicochemical properties that make them advantageous for catalysis, such as low vapor pressure, non-flammability, high thermal and chemical stabilities, and the ability to enhance the activity and stability of (bio)catalysts. ILs can improve the efficiency, selectivity, and sustainability of bio(transformations) by acting as activators of enzymes, selectively dissolving substrates and products, and reducing toxicity. They can also be recycled and reused multiple times without losing their effectiveness. ILs based on imidazolium cation are preferred for structural organization aspects, with a semiorganized layer surrounding the catalyst. ILs act as a container, providing a confined space that allows modulation of electronic and geometric effects, miscibility of reactants and products, and residence time of species. ILs can stabilize ionic and radical species and control the catalytic activity of dynamic processes. Supported IL phase (SILP) derivatives and polymeric ILs (PILs) are good options for molecular engineering of greener catalytic processes. The major factors governing metal, photo-, electro-, and biocatalysts in ILs are discussed in detail based on the vast literature available over the past two and a half decades. Catalytic reactions, ranging from hydrogenation and cross-coupling to oxidations, promoted by homogeneous and heterogeneous catalysts in both single and multiphase conditions, are extensively reviewed and discussed considering the knowledge accumulated until now.
Collapse
Affiliation(s)
- Jairton Dupont
- Institute of Chemistry - Universidade Federal do Rio Grande do Sul - UFRGS, Avenida Bento Gonçalves, 9500, Porto Alegre 91501-970 RS, Brasil
- Departamento de Bioquímica y Biología Molecular B e Inmunología, Facultad de Química, Universidad de Murcia, P.O. Box 4021, E-30100 Murcia, Spain
| | - Bárbara C Leal
- Institute of Chemistry - Universidade Federal do Rio Grande do Sul - UFRGS, Avenida Bento Gonçalves, 9500, Porto Alegre 91501-970 RS, Brasil
| | - Pedro Lozano
- Departamento de Bioquímica y Biología Molecular B e Inmunología, Facultad de Química, Universidad de Murcia, P.O. Box 4021, E-30100 Murcia, Spain
| | - Adriano L Monteiro
- Institute of Chemistry - Universidade Federal do Rio Grande do Sul - UFRGS, Avenida Bento Gonçalves, 9500, Porto Alegre 91501-970 RS, Brasil
| | - Pedro Migowski
- Institute of Chemistry - Universidade Federal do Rio Grande do Sul - UFRGS, Avenida Bento Gonçalves, 9500, Porto Alegre 91501-970 RS, Brasil
| | - Jackson D Scholten
- Institute of Chemistry - Universidade Federal do Rio Grande do Sul - UFRGS, Avenida Bento Gonçalves, 9500, Porto Alegre 91501-970 RS, Brasil
| |
Collapse
|
2
|
Zhao H. What do we learn from enzyme behaviors in organic solvents? - Structural functionalization of ionic liquids for enzyme activation and stabilization. Biotechnol Adv 2020; 45:107638. [PMID: 33002582 DOI: 10.1016/j.biotechadv.2020.107638] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 09/05/2020] [Accepted: 09/25/2020] [Indexed: 12/16/2022]
Abstract
Enzyme activity in nonaqueous media (e.g. conventional organic solvents) is typically lower than in water by several orders of magnitude. There is a rising interest of developing new nonaqueous solvent systems that are more "water-like" and more biocompatible. Therefore, we need to learn from the current state of nonaqueous biocatalysis to overcome its bottleneck and provide guidance for new solvent design. This review firstly focuses on the discussion of how organic solvent properties (such as polarity and hydrophobicity) influence the enzyme activity and stability, and how these properties impact the enzyme's conformation and dynamics. While hydrophobic organic solvents usually lead to the maintenance of enzyme activity, solvents carrying functional groups like hydroxys and ethers (including crown ethers and cyclodextrins) can lead to enzyme activation. Ionic liquids (ILs) are designable solvents that can conveniently incorporate these functional groups. Therefore, we systematically survey these ether- and/or hydroxy-functionalized ILs, and find most of them are highly compatible with enzymes leading to high activity and stability. In particular, ILs carrying both ether and tert-alcohol groups are among the most enzyme-activating solvents. Future direction is to learn from enzyme behaviors in both water and nonaqueous media to design biocompatible "water-like" solvents.
Collapse
Affiliation(s)
- Hua Zhao
- Department of Chemistry and Biochemistry, University of Northern Colorado, Greeley, CO 80639, United States.
| |
Collapse
|
3
|
Gupta MN, Alam A, Hasnain SE. Protein promiscuity in drug discovery, drug-repurposing and antibiotic resistance. Biochimie 2020; 175:50-57. [PMID: 32416199 DOI: 10.1016/j.biochi.2020.05.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 04/29/2020] [Accepted: 05/04/2020] [Indexed: 12/01/2022]
Abstract
Proteins are supposed to bind to their substrates/ligands in a specific manner via their pre-formed binding sites, according to classical biochemistry. In recent years, several types of deviations from this norm have been observed and called promiscuous behavior. Enzymatic promiscuities allow several biochemical functions to be carried out by the same enzyme. The promiscuous activity can also be the origin of "new proteins" via gene duplication. In more recent years, proteins from prokaryotes, eukaryotes and viruses have been found to have intrinsic disorder and lack a preformed binding site. Intrinsic disorder is exploited in regulatory proteins such as those that are involved in transcription and signal transduction. Such proteins function by folding locally while binding to their ligands or interacting with other proteins. These phenomena have also been classified as examples of protein promiscuity and encompass diverse kinds of ligands that can bind to a protein. Given the significant extent of structural homology in many protein families, it is not surprising that ligands also have been found to display promiscuity. Promiscuous behavior of proteins offers both challenges and opportunities to the drug discovery programs such as drug repurposing. Pathogens when exposed to antibiotics exploit protein promiscuity in several ways to develop resistance to the drug. There is increasing evidence now to support that the disorder in proteins is a major tool used by pathogens for virulence and evade drug action by exploiting protein promiscuity. This review provides a holistic view of this multi-faceted phenomenon called protein promiscuity.
Collapse
Affiliation(s)
- Munishwar N Gupta
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, New Delhi, 110016, India
| | - Anwar Alam
- ICMR-National Institute of Pathology, Safdarjung Hospital Campus, New Delhi, 110029, India
| | - Seyed E Hasnain
- JH-Institute of Molecular Medicine, Jamia Hamdard, New Delhi, 110062, India; Dr Reddy's Institute of Life Sciences, University of Hyderabad Campus, Professor CR Rao Road, Hyderabad, 500046, India.
| |
Collapse
|
4
|
Kumar M, Mukherjee J, Sinha M, Kaur P, Sharma S, Gupta MN, Singh TP. Enhancement of stability of a lipase by subjecting to three phase partitioning (TPP): structures of native and TPP-treated lipase from Thermomyces lanuginosa. ACTA ACUST UNITED AC 2015. [DOI: 10.1186/s40508-015-0042-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
5
|
Mukherjee J, Gupta MN. Molecular bioimprinting of lipases with surfactants and its functional consequences in low water media. Int J Biol Macromol 2015; 81:544-51. [PMID: 26306412 DOI: 10.1016/j.ijbiomac.2015.08.033] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Revised: 08/10/2015] [Accepted: 08/18/2015] [Indexed: 11/30/2022]
Abstract
Lipases from Thermomyces lanuginosa (TLL), Candida rugosa (CRL) and Burkholderia cepacia (BCL) were obtained in the 'open lid' form by adding surfactant molecules like n-octyl-β-d-glucopyranoside (OG), hexadecyl trimethyl ammonium bromide (CTAB), Bis(2-ethylhexyl) sulfosuccinate sodium salt (AOT) and triton X-100 for this purpose. The enzymes were 'dried' by precipitating with 4× (v/v) excess of organic solvents. The imprint surfactant molecules were removed by extensive washing with organic solvents. TLL imprinted with 0.05% CTAB showed 11-fold increase in the transesterification activity and was a better preparation to kinetically resolve (±)-1-phenylethanol. Fluorescence emission spectra confirmed that Trp89 of the lid was indeed affected during bioimprinting. With CRL, bioimprinting with OG gave 7-fold increase in the transesterification rates and resulted in reversal of enantioselectivity of CRL and gave R-phenylethyl acetate instead of the S-product as with the unimprinted precipitate. Bioimprinted BCL was also a 7-fold better catalyst for transesterification as well as enantioselectivity.
Collapse
Affiliation(s)
- Joyeeta Mukherjee
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Munishwar Nath Gupta
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India.
| |
Collapse
|
6
|
Mukherjee J, Gupta MN. Enhancing the catalytic efficiency of subtilisin for transesterification by dual bioimprinting. Tetrahedron Lett 2015. [DOI: 10.1016/j.tetlet.2015.05.101] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
7
|
Abstract
Enzymes require some flexibility for catalysis. Biotechnologists prefer stable enzymes but often this stabilization comes at the cost of reduced efficiency. Enzymes from thermophiles have low flexibility but poor catalytic rates. Enzymes from psychrophiles are less stable but show good catalytic rates at low temperature. In organic solvents enzymes perform poorly as the prior drying makes the enzyme molecules very rigid. Adding water or increasing reaction temperature improves flexibility and catalytic rates. In case of hydrolases, flexibility and enantioselectivity have interdependence. Understanding the complex role of protein flexibility in biocatalysis can help in designing biotechnological processes.
Collapse
Affiliation(s)
- Joyeeta Mukherjee
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Munishwar Nath Gupta
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| |
Collapse
|
8
|
Hernández Fernández FJ, Pérez de los Ríos A, Quesada-Medina J, Sánchez-Segado S. Ionic Liquids as Extractor Agents and Reaction Media in Ester Synthesis. CHEMBIOENG REVIEWS 2015. [DOI: 10.1002/cben.201400019] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
9
|
|
10
|
Rather GM, Gupta MN. Three phase partitioning leads to subtle structural changes in proteins. Int J Biol Macromol 2013; 60:134-40. [DOI: 10.1016/j.ijbiomac.2013.05.018] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Revised: 05/02/2013] [Accepted: 05/18/2013] [Indexed: 11/28/2022]
|
11
|
Karbalaei-Heidari HR, Shahbazi M, Absalan G. Characterization of a Novel Organic Solvent Tolerant Protease from a Moderately Halophilic Bacterium and Its Behavior in Ionic Liquids. Appl Biochem Biotechnol 2013; 170:573-86. [DOI: 10.1007/s12010-013-0215-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2012] [Accepted: 03/28/2013] [Indexed: 11/29/2022]
|
12
|
Gupta MN, Mukherjee J, Malhotra D. Use of high activity enzyme preparations in neat organic solvents for organic synthesis. ACTA ACUST UNITED AC 2013. [DOI: 10.7243/2053-7670-1-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
13
|
Roy I, Mukherjee J, Gupta MN. High activity preparations of lipases and proteases for catalysis in low water containing organic solvents and ionic liquids. Methods Mol Biol 2013; 1051:275-284. [PMID: 23934811 DOI: 10.1007/978-1-62703-550-7_18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Simple precipitation of enzymes has shown impressive catalytic efficiencies in organic solvents. In asmuch as these can be recovered after the reaction, these can be viewed as immobilized preparations just like more extensively used cross-linked enzyme aggregates (CLEAs). This chapter describes three protocols which use these enzyme precipitated and rinsed with propanol/some other appropriate organic solvent. The first two protocols show their applications in ionic liquids for a transesterification reaction and a kinetic resolution. The third protocol presumably incorporates an "imprinting" effect so that the precipitates are now able to efficiently catalyze transesterification of tributyrin with tertiary alcohols.
Collapse
Affiliation(s)
- Ipsita Roy
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, Punjab, India
| | | | | |
Collapse
|
14
|
Rather GM, Mukherjee J, Halling PJ, Gupta MN. Activation of alpha chymotrypsin by three phase partitioning is accompanied by aggregation. PLoS One 2012; 7:e49241. [PMID: 23239966 PMCID: PMC3519768 DOI: 10.1371/journal.pone.0049241] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Accepted: 10/05/2012] [Indexed: 11/18/2022] Open
Abstract
Precipitation of alpha chymotrypsin in the simultaneous presence of ammonium sulphate and t-butanol (three phase partitioning) resulted in preparations which showed self aggregation of the enzyme molecules. Precipitation with increasing amounts of ammonium sulphate led to increasing size of aggregates. While light scattering estimated the hydrodynamic diameter of these aggregates in the range of 242-1124 nm; Nanoparticle tracking analysis (NTA) gave the value as 130-462 nm. Scanning electron microscopy and gel filtration on Sephadex G-200 showed extensive aggregation in these preparations. Transmission electron microscopy showed that the aggregates had irregular shapes. All the aggregates had about 3× higher catalytic activity than the native enzyme. These aggregates did not differ in λ(max) of fluorescence emission which was around 340 nm. However, all the aggregates showed higher fluorescence emission intensity. Far-UV and near-UV circular dichroism also showed no significant structural changes as compared to the native molecule. Interestingly, HPLC gel filtration (on a hydroxylated silica column) gave 14 nm as the diameter for all preparations. Light scattering of preparations in the presence of 10% ethylene glycol also dissociated the aggregates to monomers of 14 nm. Both these results indicated that hydrophobic interactions were the driving force behind this aggregation. These results indicate: (1) Even without any major structural change, three phase partitioning led to protein molecules becoming highly prone to aggregation. (2) Different methods gave widely different estimates of sizes of aggregates. It was however possible to reconcile the data obtained with various approaches. (3) The nature of the gel filtration column is crucial and use of this technique for refolding and studying aggregation needs a rethink.
Collapse
Affiliation(s)
- Gulam Mohmad Rather
- Chemistry Department, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, India
| | - Joyeeta Mukherjee
- Chemistry Department, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, India
| | - Peter James Halling
- Department of Pure and Applied Chemistry, University of Strathclyde, Scotland, United Kingdom
| | - Munishwar Nath Gupta
- Chemistry Department, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, India
- * E-mail:
| |
Collapse
|
15
|
Moniruzzaman M, Kamiya N, Goto M. Activation and stabilization of enzymes in ionic liquids. Org Biomol Chem 2010; 8:2887-99. [PMID: 20445940 DOI: 10.1039/b926130c] [Citation(s) in RCA: 187] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
As environmentally benign "green" solvents, room temperature ionic liquids (ILs) have been used as solvents or (co)solvents in biocatalytic reactions and processes for a decade. The technological utility of enzymes can be enhanced greatly by their use in ionic liquids (ILs) rather than in conventional organic solvents or in their natural aqueous reaction media. In fact, the combination of green properties and unique tailor-made physicochemical properties make ILs excellent non-aqueous solvents for enzymatic catalysis with numerous advantages over other solvents, including high conversion rates, high selectivity, better enzyme stability, as well as better recoverability and recyclability. However, in many cases, particularly in hydrophilic ILs, enzymes show relative instability and/or lower activity compared with conventional solvents. To improve the enzyme activity as well as stability in ILs, various attempts have been made by modifying the form of the enzymes. Examples are enzyme immobilization onto support materials via adsorption or multipoint attachment, lyophilization in the presence of stabilizing agents, chemical modification with stabilizing agents, formation of cross-linked enzyme aggregates, pretreatment with polar organic solvents or enzymes combined with suitable surfactants to form microemulsions. The use of these enzyme preparations in ILs can dramatically increase the solvent tolerance, enhance activity as well as stability, and improve enantioselectivity. This perspective highlights a number of pronounced strategies being used successfully for activation and stabilization of enzymes in non-aqueous ILs media. This review is not intended to be comprehensive, but rather to present a general overview of the potential approaches to activate enzymes for diverse enzymatic processes and biotransformations in ILs.
Collapse
Affiliation(s)
- Muhammad Moniruzzaman
- Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, 744 Moto-oka, Fukuoka 819-0395, Japan
| | | | | |
Collapse
|
16
|
Gorke J, Srienc F, Kazlauskas R. Toward advanced ionic liquids. Polar, enzyme-friendly solvents for biocatalysis. BIOTECHNOL BIOPROC E 2010; 15:40-53. [PMID: 34290544 DOI: 10.1007/s12257-009-3079-z] [Citation(s) in RCA: 162] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Ionic liquids, also called molten salts, are mixtures of cations and anions that melt below 100 °C. Typical ionic liquids are dialkylimidazolium cations with weakly coordinating anions such as [MeOSO3] or [PF6]. Advanced ionic liquids such as choline citrate have biodegradable, less expensive and less toxic anions and cations. Deep eutectic solvents are also included in the advanced ionic liquids. Deep eutectic solvents are mixtures of salts such as choline chloride and uncharged hydrogen bond donors such as urea, oxalic acid, or glycerol. For example, a mixture of choline chloride and urea in 1:2 molar ratio liquifies to form a deep eutectic solvent. Their properties are similar to those of ionic liquids. Water-miscible ionic liquids as cosolvents with water enhance the solubility of substrates or products. Although traditional water-miscible organic solvents also enhance solubility, they often inactivate enzymes, while ionic liquids do not. The enhanced solubility of substrates can increase the rate of reaction and often increases the regio- or enantioselectivity. Ionic liquids can also be solvents for non-aqueous reactions. In these cases, they are especially suited to dissolve polar substrates. Polar organic solvent alternatives inactivate enzymes, but ionic liquids do not even when they have similar polarities. Besides their solubility properties, ionic liquids and deep eutectic solvents may be greener than organic solvents because ionic liquids are non-volatile and can be made from non-toxic components. This review covers selected examples of enzyme catalyzed reaction ionic liquids that demonstrate their advantages and unique properties and point out opportunities for new applications. Most examples involve hydrolases, but oxidoreductases and even whole cell reactions have been reported in ionic liquids.
Collapse
Affiliation(s)
- Johnathan Gorke
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, 140 Gortner Laboratory, 1479 Gortner Ave., Saint Paul, MN 55108, USA.,BioTechnology Institute, 240 Gortner Laboratory, University of Minnesota, 1479 Gortner Ave., Saint Paul, MN 55108, USA.,Department of Chemical Engineering and Materials Science, University of Minnesota, 151 Amundson Hall, 421 Washington Ave. SE, Minneapolis, MN 55455, USA
| | - Friedrich Srienc
- BioTechnology Institute, 240 Gortner Laboratory, University of Minnesota, 1479 Gortner Ave., Saint Paul, MN 55108, USA.,Department of Chemical Engineering and Materials Science, University of Minnesota, 151 Amundson Hall, 421 Washington Ave. SE, Minneapolis, MN 55455, USA
| | - Romas Kazlauskas
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, 140 Gortner Laboratory, 1479 Gortner Ave., Saint Paul, MN 55108, USA.,BioTechnology Institute, 240 Gortner Laboratory, University of Minnesota, 1479 Gortner Ave., Saint Paul, MN 55108, USA
| |
Collapse
|
17
|
Moniruzzaman M, Nakashima K, Kamiya N, Goto M. Recent advances of enzymatic reactions in ionic liquids. Biochem Eng J 2010. [DOI: 10.1016/j.bej.2009.10.002] [Citation(s) in RCA: 376] [Impact Index Per Article: 26.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
18
|
|
19
|
Solanki K, Shah S, Nath Gupta M. Chemical modification of alpha-chymotrypsin for obtaining high transesterification activity in low water organic media. BIOCATAL BIOTRANSFOR 2009. [DOI: 10.1080/10242420801897361] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
20
|
Domínguez de María P. "Nonsolvent" applications of ionic liquids in biotransformations and organocatalysis. Angew Chem Int Ed Engl 2008; 47:6960-8. [PMID: 18651677 DOI: 10.1002/anie.200703305] [Citation(s) in RCA: 157] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The application of room-temperature ionic liquids (RTILs) as (co)solvents and/or reagents is well documented. However, RTILS also have "nonsolvent" applications in biotransformations and organocatalysis. Examples are the anchoring of substrates to RTILs; ionic-liquid-coated enzymes (ILCE) and enzyme-IL colyophilization; the construction of biocatalytic ternary reaction systems; the combination of enzymes, RTILs, membranes, and (bio)electrochemistry; and ionic-liquid-supported organocatalysts. These strategies provide more robust, more efficient, and more enantioselective bio- and organocatalysts with many practical applications. As shown herein, RTILs offer a wide range of promising alternatives to conventional chemistry.
Collapse
Affiliation(s)
- Pablo Domínguez de María
- AkzoNobel BV, Chemicals Process and Product Technology Department, Velperweg 76, P.O. Box 9300, 6800 SB Arnhem, The Netherlands.
| |
Collapse
|
21
|
Domínguez de María P. “Nonsolvens”-Anwendungen von ionischen Flüssigkeiten bei Biotransformationen und in der Organokatalyse. Angew Chem Int Ed Engl 2008. [DOI: 10.1002/ange.200703305] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
22
|
Nakashima K, Maruyama T, Kamiya N, Goto M. Spectrophotometric assay for protease activity in ionic liquids using chromogenic substrates. Anal Biochem 2008; 374:285-90. [DOI: 10.1016/j.ab.2007.11.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2007] [Revised: 11/06/2007] [Accepted: 11/09/2007] [Indexed: 10/22/2022]
|
23
|
Solanki K, Gupta MN. Optimising biocatalyst design for obtaining high transesterification activity by alpha-chymotrypsin in non-aqueous media. Chem Cent J 2008; 2:2. [PMID: 18269743 PMCID: PMC2262082 DOI: 10.1186/1752-153x-2-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2007] [Accepted: 02/12/2008] [Indexed: 11/12/2022] Open
Abstract
Background Enzymes are often used in organic solvents for catalyzing organic synthesis. Two enzyme preparations, EPRP (enzyme precipitated and rinsed with n-propanol) and PCMC (protein coated microcrystals) show much higher activities than lyophilized powders in such systems. Both preparations involve precipitation by an organic solvent. The clear understanding of why these preparations show higher catalytic activity than lyophilized powders in organic solvents is not available. Results It was found that EPRPs of α-chymotrypsin prepared by precipitation with n-propanol in the presence of trehalose contained substantial amount of trehalose (even though trehalose alone at these lower concentrations was not precipitated by n-propanol). The presence of trehalose in these EPRPs resulted in much higher transesterification rates (45.2 nmoles mg-1min-1) as compared with EPRPs prepared in the absence of trehalose (16.6 nmoles mg-1min-1) in octane. Both kinds of EPRPs gave similar initial transesterification rates in acetonitrile. Use of higher concentrations of trehalose (when trehalose alone also precipitates out), resulted in the formation of PCMCs, which showed higher transesterification rates in both octane and acetonitrile. SEM analysis showed the relative sizes of various preparations. Presence of trehalose resulted in EPRPs of smaller sizes. Conclusion The two different forms of enzymes (EPRP and PCMC) known to show higher activity in organic solvents were found to be different only in the way the low molecular weight additive was present along with the protein. Therefore, the enhancement in the transesterification activity in EPRPs prepared in the presence of trehalose was due to: (a) better retention of essential water layer for catalysis due to the presence of the sugar. This effect disappeared where the reaction media was polar as the polar solvent (acetonitrile) is more effective in stripping off the water from the enzyme; (b) reduction in particle size as revealed by SEM. In the case of PCMC, the enhancement in the initial rates was due to an increase in the surface area of the biocatalyst since protein is coated over the core material (trehalose or salt). It is hoped that the insight gained in this work would help in a better understanding for designing high activity biocatalyst preparation of non-aqueous media.
Collapse
Affiliation(s)
- Kusum Solanki
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, India.
| | | |
Collapse
|
24
|
Shah S, Solanki K, Gupta MN. Enhancement of lipase activity in non-aqueous media upon immobilization on multi-walled carbon nanotubes. Chem Cent J 2007; 1:30. [PMID: 18047656 PMCID: PMC2211749 DOI: 10.1186/1752-153x-1-30] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2007] [Accepted: 11/29/2007] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND Immobilization of biologically active proteins on nanosized surfaces is a key process in bionanofabrication. Carbon nanotubes with their high surface areas, as well as useful electronic, thermal and mechanical properties, constitute important building blocks in the fabrication of novel functional materials. RESULTS Lipases from Candida rugosa (CRL) were found to be adsorbed on the multiwalled carbon nanotubes with very high retention of their biological activity (97%). The immobilized biocatalyst showed 2.2- and 14-fold increases in the initial rates of transesterification activity in nearly anhydrous hexane and water immiscible ionic liquid [Bmim] [PF6] respectively, as compared to the lyophilized powdered enzyme. It is presumed that the interaction with the hydrophobic surface of the nanotubes resulted in conformational changes leading to the 'open lid' structure of CRL. The immobilized enzyme was found to give 64% conversion over 24 h (as opposed to 14% with free enzyme) in the formation of butylbutyrate in nearly anhydrous hexane. Similarly, with ionic liquid [Bmim] [PF6], the immobilized enzyme allowed 71% conversion as compared to 16% with the free enzyme. The immobilized lipase also showed high enantioselectivity as determined by kinetic resolution of (+/-) 1-phenylethanol in [Bmim] [PF6]. While free CRL gave only 5% conversion after 36 h, the immobilized enzyme resulted in 37% conversion with > 99% enantiomeric excess. TEM studies on the immobilized biocatalyst showed that the enzyme is attached to the multiwalled nanotubes. CONCLUSION Successful immobilization of enzymes on nanosized carriers could pave the way for reduced reactor volumes required for biotransformations, as well as having a use in the construction of miniaturized biosensensor devices.
Collapse
Affiliation(s)
- Shweta Shah
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India
| | - Kusum Solanki
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India
| | - Munishwar N Gupta
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India
| |
Collapse
|
25
|
Weuster-Botz D. Process intensification of whole-cell biocatalysis with ionic liquids. CHEM REC 2007; 7:334-40. [DOI: 10.1002/tcr.20130] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|