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Rarokar N, Yadav S, Saoji S, Bramhe P, Agade R, Gurav S, Khedekar P, Subramaniyan V, Wong LS, Kumarasamy V. Magnetic nanosystem a tool for targeted delivery and diagnostic application: Current challenges and recent advancement. Int J Pharm X 2024; 7:100231. [PMID: 38322276 PMCID: PMC10844979 DOI: 10.1016/j.ijpx.2024.100231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 01/11/2024] [Accepted: 01/17/2024] [Indexed: 02/08/2024] Open
Abstract
Over the last two decades, researchers have paid more attention to magnetic nanosystems due to their wide application in diverse fields. The metal nanomaterials' antimicrobial and biocidal properties make them an essential nanosystem for biomedical applications. Moreover, the magnetic nanosystems could have also been used for diagnosis and treatment because of their magnetic, optical, and fluorescence properties. Superparamagnetic iron oxide nanoparticles (SPIONs) and quantum dots (QDs) are the most widely used magnetic nanosystems prepared by a simple process. By surface modification, researchers have recently been working on conjugating metals like silica, copper, and gold with magnetic nanosystems. This hybridization of the nanosystems modifies the structural characteristics of the nanomaterials and helps to improve their efficacy for targeted drug and gene delivery. The hybridization of metals with various nanomaterials like micelles, cubosomes, liposomes, and polymeric nanomaterials is gaining more interest due to their nanometer size range and nontoxic, biocompatible nature. Moreover, they have good injectability and higher targeting ability by accumulation at the target site by application of an external magnetic field. The present article discussed the magnetic nanosystem in more detail regarding their structure, properties, interaction with the biological system, and diagnostic applications.
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Affiliation(s)
- Nilesh Rarokar
- Department of Pharmaceutical Sciences, Rashtrasant Tukadoji Maharaj University, Nagpur, Maharashtra 440033, India
- G H Raisoni Institute of Life Sciences, Shradha Park, Hingna MIDC, Nagpur 440016, India
| | - Sakshi Yadav
- Department of Pharmaceutical Sciences, Rashtrasant Tukadoji Maharaj University, Nagpur, Maharashtra 440033, India
| | - Suprit Saoji
- Department of Pharmaceutical Sciences, Rashtrasant Tukadoji Maharaj University, Nagpur, Maharashtra 440033, India
| | - Pratiksha Bramhe
- Department of Pharmaceutical Sciences, Rashtrasant Tukadoji Maharaj University, Nagpur, Maharashtra 440033, India
| | - Rishabh Agade
- Department of Pharmaceutical Sciences, Rashtrasant Tukadoji Maharaj University, Nagpur, Maharashtra 440033, India
| | - Shailendra Gurav
- Department of Pharmacognosy, Goa College of Pharmacy, Panaji, Goa University, Goa 403 001, India
| | - Pramod Khedekar
- Department of Pharmaceutical Sciences, Rashtrasant Tukadoji Maharaj University, Nagpur, Maharashtra 440033, India
| | - Vetriselvan Subramaniyan
- Pharmacology Unit, Jeffrey Cheah School of Medicine and Health Sciences, MONASH University, Jalan Lagoon Selatan, Bandar Sunway, 47500 Subang Jaya, Selangor, Malaysia
| | - Ling Shing Wong
- Faculty of Health and Life Sciences, INTI International University, Nilai 71800, Malaysia
| | - Vinoth Kumarasamy
- Department of Parasitology, Medical Entomology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latif, 56000 Cheras, Kuala Lumpur, Malaysia
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Cortes-Clerget M, Yu J, Kincaid JRA, Walde P, Gallou F, Lipshutz BH. Water as the reaction medium in organic chemistry: from our worst enemy to our best friend. Chem Sci 2021; 12:4237-4266. [PMID: 34163692 PMCID: PMC8179471 DOI: 10.1039/d0sc06000c] [Citation(s) in RCA: 155] [Impact Index Per Article: 51.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Accepted: 01/02/2021] [Indexed: 12/22/2022] Open
Abstract
A review presenting water as the logical reaction medium for the future of organic chemistry. A discussion is offered that covers both the "on water" and "in water" phenomena, and how water is playing unique roles in each, specifically with regard to its use in organic synthesis.
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Affiliation(s)
| | - Julie Yu
- Department of Chemistry & Biochemistry, University of California Santa Barbara California 93106 USA
| | - Joseph R A Kincaid
- Department of Chemistry & Biochemistry, University of California Santa Barbara California 93106 USA
| | - Peter Walde
- Department of Materials, ETH Zurich Zurich Switzerland
| | - Fabrice Gallou
- Chemical & Analytical Development Novartis Pharma AG 4056 Basel Switzerland
| | - Bruce H Lipshutz
- Department of Chemistry & Biochemistry, University of California Santa Barbara California 93106 USA
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Salvati Manni L, Fong WK, Mezzenga R. Lipid-based mesophases as matrices for nanoscale reactions. NANOSCALE HORIZONS 2020; 5:914-927. [PMID: 32322863 DOI: 10.1039/d0nh00079e] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Lipidic mesophases are versatile bioorganic materials that have been effectively employed as nanoscale matrices for membrane protein crystallization, drug delivery and as food emulsifiers over the last 30 years. In this review, the focus is upon studies that have employed non-lamellar lipid mesophases as matrices for organic, inorganic and enzymatic reactions. The ability of lipidic mesophases to incorporate hydrophilic, amphiphilic and hydrophobic molecules, together with the high interfacial area of the lipidic cubic and inverse hexagonal phases has been exploited in heterogeneous catalysis as well as for enzyme immobilization. The unique nanostructure of these mesophases is the driving force behind their ability to act as templates for synthesis, resulting in the creation of highly ordered polymeric and inorganic materials with complex geometries.
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Affiliation(s)
- Livia Salvati Manni
- Department of Health Sciences and Technology, Swiss Federal Institute of Technology in Zurich, 8092 Zurich, Switzerland.
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Wilson CJ, Bommarius AS, Champion JA, Chernoff YO, Lynn DG, Paravastu AK, Liang C, Hsieh MC, Heemstra JM. Biomolecular Assemblies: Moving from Observation to Predictive Design. Chem Rev 2018; 118:11519-11574. [PMID: 30281290 PMCID: PMC6650774 DOI: 10.1021/acs.chemrev.8b00038] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Biomolecular assembly is a key driving force in nearly all life processes, providing structure, information storage, and communication within cells and at the whole organism level. These assembly processes rely on precise interactions between functional groups on nucleic acids, proteins, carbohydrates, and small molecules, and can be fine-tuned to span a range of time, length, and complexity scales. Recognizing the power of these motifs, researchers have sought to emulate and engineer biomolecular assemblies in the laboratory, with goals ranging from modulating cellular function to the creation of new polymeric materials. In most cases, engineering efforts are inspired or informed by understanding the structure and properties of naturally occurring assemblies, which has in turn fueled the development of predictive models that enable computational design of novel assemblies. This Review will focus on selected examples of protein assemblies, highlighting the story arc from initial discovery of an assembly, through initial engineering attempts, toward the ultimate goal of predictive design. The aim of this Review is to highlight areas where significant progress has been made, as well as to outline remaining challenges, as solving these challenges will be the key that unlocks the full power of biomolecules for advances in technology and medicine.
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Affiliation(s)
- Corey J. Wilson
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Andreas S. Bommarius
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Julie A. Champion
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Yury O. Chernoff
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
- Laboratory of Amyloid Biology & Institute of Translational Biomedicine, St. Petersburg State University, St. Petersburg 199034, Russia
| | - David G. Lynn
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Anant K. Paravastu
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Chen Liang
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Ming-Chien Hsieh
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Jennifer M. Heemstra
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
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Regulation of acid phosphatase in reverse micellar system by lipids additives: Structural aspects. J Colloid Interface Sci 2011; 353:490-7. [DOI: 10.1016/j.jcis.2010.09.072] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2010] [Revised: 09/22/2010] [Accepted: 09/24/2010] [Indexed: 11/22/2022]
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Liu T, Li J. Effects of Aspartic Acid and Lysine on Thermodynamic Functions of SDS Micellization. CHINESE J CHEM 2010. [DOI: 10.1002/cjoc.201090357] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Bru R, Sanchez-Ferrer A, García-Carmona F. Characteristics of tyrosinase in AOT-isooctane reverse micelles. Biotechnol Bioeng 2010; 34:304-8. [PMID: 18588108 DOI: 10.1002/bit.260340305] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Isooctane-AOT-H(2)O is a suitable system for studying enzyme behavior in organic solvents. Tyrosinase was able to catalyze a well-known reaction in aqueous medium: oxidation of 4-methylcatechol to yield 4-methyl-o-benzoquinone. This reaction was studied using the preceding ternary system with adequate amounts of each component to make up reverse micelles. 4-Methyl-o-benzoquinone stability was demonstrated in isooctane even at alkaline pH values. Apparent K(m) and V(max) were similar to those in water, but substrate inhibition was more evident. The pH and temperature appear to be shifted toward high and low values, respectively. Characteristic parameters of reverse micelles, omega(0) (= H(2)O/AOT) and percentage of H(2)O (v/v), were investigated. The results obtained showed that the steady-state rate varies either with omega(0) or with percentage of H(2)O. The variation observed with omega(0) showed an optimal value while an increase in percentage of H(2)O can lead to decreased or increased activity depending on substrate concentration.
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Affiliation(s)
- R Bru
- Departamento de Bioquímica, Universidad de Murcia, Murcia, Spain
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Wallin R, Engström S, Mandenius CF. Stabilisation of Glucose Oxidase by Entrapment in a Cubic Liquid Crystalline Phase. ACTA ACUST UNITED AC 2009. [DOI: 10.3109/10242429309030957] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Ronnie Wallin
- Food Technology, Chemical Center, POB 124, S-221 00, Lund, Sweden
| | - Sven Engström
- Food Technology, Chemical Center, POB 124, S-221 00, Lund, Sweden
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Pshezhetsky AV, Klyachko NL, Levashov AV, Martinek K. Catalysis by Laccase (FromCoriolus uersicolor) in Microheterogeneous Media of the Water/Organic Solvent/Surfactant Type. ACTA ACUST UNITED AC 2009. [DOI: 10.3109/10242429008992090] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
| | - N. L. Klyachko
- Chemistry Department, Moscow State University, SU-117234, USSR
| | - A. V. Levashov
- Chemistry Department, Moscow State University, SU-117234, USSR
| | - Karel Martinek
- Institute of Organic Chemistry and Biochemistry, Czechoslovak Academy of Sciences, CS-16610, Prague, Czechoslovakia
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10
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Klyachko N, Ignatenko O, Dmitrieva N, Eshchina A, Rainina E, Kazarov A, Kuptsova O, Levashov A. Matrix design for bacteriolytic enzyme encapsulation. J Drug Deliv Sci Technol 2006. [DOI: 10.1016/s1773-2247(06)50053-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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11
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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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MINE YURIE, FUKUNAGA KIMITOSHI, SAMEJIMA KENICHI, YOSHIMOTO MAKOTO, NAKAO KATSUMI, SUGIMURA YOSHIAKI. Structural Effects of Amphiphiles on Candida rugosa Lipase Activation by Freeze-Drying of Aqueous Solution of Enzyme and Amphiphile. J Biosci Bioeng 2004. [DOI: 10.1263/jbb.96.525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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13
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Klyachko NL, Levashov AV. Bioorganic synthesis in reverse micelles and related systems. Curr Opin Colloid Interface Sci 2003. [DOI: 10.1016/s1359-0294(03)00016-5] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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14
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Shipovskov S, Ferapontova E, Ruzgas T, Levashov A. Stabilisation of tyrosinase by reversed micelles for bioelectrocatalysis in dry organic media. BIOCHIMICA ET BIOPHYSICA ACTA 2003; 1620:119-24. [PMID: 12595080 DOI: 10.1016/s0304-4165(02)00513-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The enzymatic and bioelectrocatalytic activity of tyrosinase from mushrooms was studied in a system of reversed micelles formed by Aerosol OT (AOT) in hexane. The optimal catechol oxidising activity of tyrosinase incorporated in reversed micelles was found at a hydration degree of w(0)=25. The catalytic activity was comparable with tyrosinase activity in aqueous media. When immobilized at an Au electrode, either directly or in reversed micelles, tyrosinase exhibited a similar efficiency of the bioelectrocatalytic reduction of O(2) mediated by catechol; however, a rapid decrease in the activity correlated with the destruction of reversed micelles and/or the removal of tyrosinase from the electrode surface. The system containing tyrosinase in reversed micelles with caoutchouk, spread on the surface of the Au electrode and successively covered with a Nafion membrane layer, was found to result in stable tyrosinase-modified electrodes, which were resistant to inactivation in dry acetonitrile. The proposed technique offers possibilities for further development of highly active and stable surfactant/enzyme-modified electrodes for measurements carried out in organic solvents.
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Affiliation(s)
- Stepan Shipovskov
- Department of Chemical Enzymology, Chemical Faculty, Moscow State University, Russia.
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15
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Mine Y, Fukunaga K, Samejima KI, Yoshimoto M, Nakao K, Sugimura Y. Structural effects of amphiphiles on Candida rugosa lipase activation by freeze-drying of aqueous solution of enzyme and amphiphile. J Biosci Bioeng 2003; 96:525-8. [PMID: 16233568 DOI: 10.1016/s1389-1723(04)70144-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2003] [Accepted: 09/09/2003] [Indexed: 11/18/2022]
Abstract
Lipases co-lyophilized with water-soluble gemini-type amphiphiles were found to have high enzyme activity in nonaqueous media without washing out of the amphiphile with anhydrous organic solvent. In this study, we obtained freeze-dried complexes of Candida rugosa lipase (CRL) with six water-soluble twin glusitol-headed amphiphiles bearing different types of hydrophobic tails, including newly synthesized ones, and their transesterification activity in organic solvent was evaluated. The results indicate that the increased enzyme activity upon CRL modification at 200 molar ratio of amphiphile/CRL, which are restricted to the ester-containing amphiphiles, is probably due to the surface activation by the interaction between ester-carbonyl of the amphiphile and phenyl group of the tyrosine residue situated on the surface of the lid in the CRL.
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Affiliation(s)
- Yurie Mine
- Department of Applied Chemistry and Chemical Engineering, Faculty of Engineering, Yamaguchi University, 2-16-1 Tokiwadai, Ube 755-8611, Japan
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Klyachko N, Levashov P, Köhling R, Woenckhaus J, Balny C, Winter R, Levashov A. Enzymes in membrane-like surfactant-based media: perspectives for pressure regulation. ACTA ACUST UNITED AC 2002. [DOI: 10.1016/s0921-0423(02)80094-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2023]
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17
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Sa´nchez-Ferrer A, Bru R, Garci´a-Carmona F. Kinetic properties of polyphenoloxidase in organic solvents A study in Brij 96-cyclohexane reverse micelles. FEBS Lett 2001. [DOI: 10.1016/0014-5793(88)80461-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Jourquin G, Kauffmann JM. Fluorimetric determination of theophylline in serum by inhibition of bovine alkaline phosphatase in AOT based water/in oil microemulsion. J Pharm Biomed Anal 1998; 18:585-96. [PMID: 9919959 DOI: 10.1016/s0731-7085(98)00264-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Theophylline is an effective bronchodilatator used in the treatment of asthma which requires frequent control because of its narrow therapeutic index. Over the past decade much attention has been dedicated to the peculiar properties of the inner water pools of AOT (sodium 2-bishexyl-ethyl sulfosuccinate) microemulsions as enzyme microreactors, yet few analytical applications of the latter have been reported. We developed an original assay based on the uncompetitive inhibition by theophylline of the reaction catalyzed by alkaline phosphatase from bovine liver (E.C. 3.1.3.1) of the ELF-97 fluorogenic substrate in borate buffer 20 mM (pH 8.6)/AOT/iso-octane-ethyl acetate (95:5) at a temperature of 37 degrees C. Optimal activity of endogenous plasmatic alkaline phosphatase isoenzymes approximately pH 10.5, interfering activity of the serum are avoided. The assay is multiple point rate, monitoring the appearance of the photostable fluorescence emission of the reaction product (510-530 nm) out of the water pool. The influence of several parameters such as the amount of buffer (W(o)), the amount of alkaline phosphatase, sample volume (10-30 microl) [corrected], optimal run time (1-7 min) and the use of phosphorylating acceptor (2A2MP) are discussed. The method was compared to HPLC UV and TDx methods.
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Affiliation(s)
- G Jourquin
- Pharmaceutical Institute, Free University of Brussels, Belgium.
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Carion-Taravella B, Lesieur S, Ollivon M, Chopineau J. Enzyme-Mediated Formation of Vesicles from DPPC−Dodecyl Maltoside Mixed Micelles. J Am Chem Soc 1998. [DOI: 10.1021/ja980400a] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Brigitte Carion-Taravella
- Contribution from the Laboratoire de Technologie Enzymatique, CNRS UPRES A 6022, 60205 Compiègne, France, and Equipe Physicochimie des Systèmes Polyphasés, CNRS URA 1218, 92296 Châtenay-Malabry, France
| | - Sylviane Lesieur
- Contribution from the Laboratoire de Technologie Enzymatique, CNRS UPRES A 6022, 60205 Compiègne, France, and Equipe Physicochimie des Systèmes Polyphasés, CNRS URA 1218, 92296 Châtenay-Malabry, France
| | - Michel Ollivon
- Contribution from the Laboratoire de Technologie Enzymatique, CNRS UPRES A 6022, 60205 Compiègne, France, and Equipe Physicochimie des Systèmes Polyphasés, CNRS URA 1218, 92296 Châtenay-Malabry, France
| | - Joël Chopineau
- Contribution from the Laboratoire de Technologie Enzymatique, CNRS UPRES A 6022, 60205 Compiègne, France, and Equipe Physicochimie des Systèmes Polyphasés, CNRS URA 1218, 92296 Châtenay-Malabry, France
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20
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Shapiro YE, Pykhteeva EG, Levashov AV. 1H NMR Self-Diffusion in Polymer-Surfactant Nanocapsules and Cryogels with Enzyme. J Colloid Interface Sci 1998; 206:168-176. [PMID: 9761640 DOI: 10.1006/jcis.1998.5691] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The multicomponent self-diffusion in nanocapsules and cryogel biocatalytic systems containing alpha-chymotrypsin has been studied with the NMR-PGSE method at various temperatures and compared with the diffusion of such systems without enzyme. Unilamellar vesicles have been formed in water after "coating" with Brij-97 of the poly-(N,N-diallyl-N,N-didodecyl ammonium bromide), poly-DDAB, nanocapsules. The latter have been obtained by UV-irradiation of reversed hydrated micelles from DDAB in cyclohexane. Cryogels were made from poly(vinyl alcohol), PVA, aqueous solutions by a freezing-thawing cyclic process. Both compartmented systems were used as vehicles of the enzyme entrapped in inner aqueous cavities. The activation energies of self-diffusion for both these systems have been calculated. These data contain information concerning morphology and molecular packing. Encapsulation of alpha-chymotrypsin in the poly-DDAB/Brij-97 vesicles and the PVA cryogel lowers the Ds values for all molecules and shifts the cloud point toward the lower temperature. On the contrary, the syneresis point for the PVA cryogel is shifted for 8 degrees toward the higher temperature by the entrapment of the enzyme. Besides, entrapment of alpha-chymotrypsin in the cryogel promotes the increase of the Ea values for the PVA chain on 1.5 kJ/mol below the syneresis point. Such a difference indicates the influence of the H-bond system of PVA hydroxyl groups and water molecules on the interference of the protein globule. Entrapment of alpha-chymotrypsin leads to consolidation of this H-bond system. Copyright 1998 Academic Press.
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Affiliation(s)
- YE Shapiro
- Physical Chemistry, The Royal Institute of Technology, Stockholm, S-100 44, Sweden
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21
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Immobilization of α-chymotrypsin into the poly(N,N-diallyl-N,N-didodecyl ammonium bromiae)/surfactant nanocapsules. Appl Biochem Biotechnol 1998. [DOI: 10.1007/bf02787174] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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22
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Anarbaev RO, Elepov IB, Lavrik OI. Klenow fragment and DNA polymerase alpha-primase fromserva calf thymus in water-in-oil microemulsions. BIOCHIMICA ET BIOPHYSICA ACTA 1998; 1384:315-24. [PMID: 9659393 DOI: 10.1016/s0167-4838(98)00025-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The activity of DNA polymerase alpha-primase complex from calf thymus and Klenow fragment of E. coli DNA polymerase 1 has been studied in reverse microemulsions formed by sodium bis(2-ethylhexyl) sulfosuccinate (AOT), sodium dodecylsulfate (SDS), cetyl trimethyl ammonium bromide (CTAB), polyoxyethylene 20 cetyl ether (Brij 58), and Triton X-114 in decane. DNA polymerases were not active in AOT, CTAB, and SDS reverse microemulsions, but these enzymes catalyzed DNA synthesis in Brij 58 and its mixture with other surfactants. We have also found the system composed from the Triton X-114, SDS, CTAB, and Brij 58 (concentration of 128, 25, 15, and 10 mM, respectively) in hexanol-decane (1:12 v/v), in which DNA polymerases revealed maximum activity. The above system was optically transparent, fluid, and stable during a few hours with a water-surfactants molar ratio up to 160. The pH dependence of DNA polymerase activity was not significantly different in comparison with water; however, DNA polymerase was sensitive to ionic strength in microemulsions. The dependence of DNA polymerase activity on w0 was the curve with a few optima. DNA polymerases synthesized more products in water than in reverse microemulsions, and the processivity of Klenow fragment decreased. An increase of the water content resulted in an increase of DNA polymerase processivity.
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Affiliation(s)
- R O Anarbaev
- Novosibirsk Institute of Bioorganic Chemistry, Russian Federation
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Chopineau J, Lesieur S, Carion-Taravella B, Ollivon M. Self-evolving microstructured systems upon enzymatic catalysis. Biochimie 1998; 80:421-35. [PMID: 9782383 DOI: 10.1016/s0300-9084(00)80010-3] [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: 11/22/2022]
Abstract
The consequences of cell microstructuration on enzyme functions is discussed in the framework of self-evolving microstructured systems. Molecular assemblies of amphiphiles or lipids are spontaneously formed by self-organisation. Among these different structures, reversed micelles, liquid crystalline mesophases and vesicles are hosts for enzymatic reaction studies. Inside a living cell, phospholipid metabolism is responsible for membrane structural modifications; the catalytic behaviour of lipolytic enzymes, mainly phospholipase (PL) A2, is described in relation with structural aspects of biological membranes. The implication in cellular regulation events of PLC and PLD is discussed in relation with the role of their reaction products as second messengers in membrane fusion processes. The in vitro synthesis of dialkyl phosphatidylcholines, via the enzymatic 'salvage pathway' which leads to the formation of vesicles upon phospholipid formation, is considered in relation with autopoiesis. More recent studies on self-evolving systems based on enzyme-surfactants reactions are detailed. The interactions between amphiphilic aggregates and enzymes allow to explore the OG/octanol/water phase diagram. Enzymatic formation of dipalmitoylphosphatidylcholine (DPPC) liposomes and non-ionic surfactant vesicles (NSV), starting from mixed micelles or open structures, finally sets an example of a biomimetic self-evolving system.
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Affiliation(s)
- J Chopineau
- Laboratoire de Technologie Enzymatique, CNRS-UPRESA 6022, Compiègne, France
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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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López Pérez JA, López Quintela MA, Mira J, Rivas J, Charles SW. Advances in the Preparation of Magnetic Nanoparticles by the Microemulsion Method. J Phys Chem B 1997. [DOI: 10.1021/jp972046t] [Citation(s) in RCA: 214] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | | | | | | | - S. W. Charles
- Department of Chemistry, University College of North Wales, Bangor, Gwynedd LL57 2UW, United Kingdom
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Kurganov BI, Topchieva IN, Efremova NV. Protein conjugates with water-soluble poly(alkylene oxide)s entrapped in hydrated reversed micelles. Bioconjug Chem 1997; 8:637-42. [PMID: 9327125 DOI: 10.1021/bc970041t] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Conjugates of alpha-chymotrypsin (ChT) with poly(ethylene glycol) (PEG) and block copolymers of ethylene and propylene oxides (proxanols) have been synthesized. The molecular mass of the polymers used was 2 kDa. The conjugates contained five to seven polymer chains per enzyme molecule. Hydrolysis of N-trans-cinnamoylimidazole catalyzed by the conjugates of ChT with poly(alkylene oxide)s was studied in 0.05 M Tris-HCl buffer at pH 8.0 and in the system of the hydrated reversed micelles of aerosol OT (AOT) in octane at 25 degrees C. The deacylation rate constant k3 for the conjugates in buffer solution was 1.5-1.8-fold higher than that for native ChT. The value of the [H2O]:[AOT] ratio corresponding to the maximum on k3 versus [H2O]:[AOT] curves for the conjugates (ca. 16) allows the dimensions of their molecules to be evaluated. The radius of the conjugate molecules was found to be about 2.8 nm. The value of k3 for the conjugate of ChT with PEG, as in the case of native ChT, remains constant when the concentration of AOT is varied. However, the deacylation rate constant for the conjugates of ChT with proxanols decreases with the increase in AOT concentration, which indicates that these conjugates are able to interact with the micellar matrix and therefore may be considered membranotropic compounds.
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Affiliation(s)
- B I Kurganov
- A. N. Bach Institute of Biochemistry, Russian Academy of Sciences, Moscow, Russia
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27
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28
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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]
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29
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Affiliation(s)
- R Bru
- Departamento de Bioquímica y Biología Molecular A, Universidad de Murcia, Spain
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Oh SG, Kizling J, Holmberg K. Microemulsions as reaction media for the synthesis of sodium decyl sulfonate 1: Role of microemulsion composition. Colloids Surf A Physicochem Eng Asp 1995. [DOI: 10.1016/0927-7757(94)03064-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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31
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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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32
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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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33
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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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34
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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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36
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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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37
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Chang GG, Shiao SL. Possible kinetic mechanism of human placental alkaline phosphatase in vivo as implemented in reverse micelles. EUROPEAN JOURNAL OF BIOCHEMISTRY 1994; 220:861-70. [PMID: 8143740 DOI: 10.1111/j.1432-1033.1994.tb18689.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Human placental alkaline phosphatase is an integral membrane protein. It catalyzes the hydrolysis of phosphoester linkage of a broad-range substrate. We have embedded the enzyme in a reverse micellar system prepared by dissolving the surfactant sodium bis(2-ethylhexyl)sulfosuccinate (AOT) in isooctane. Linear Lineweaver-Burk and Eadie-Hofstee plots for the substrate and linear Arrhenius plot for the temperature-dependent enzyme reaction were obtained in reverse micelles suggesting that the substrate diffusion limitation was not a rate-limiting step in the system and exchange of materials between reverse micelles was very rapid. The catalytic constant (kcat) of the enzyme was decreased, and the Km for the substrate was increased in reverse micelles, both in an exponential way with the [H2O]/ AOT] ratio (omega O). The enzyme was more stable in reverse micelles than in aqueous solution at 30 degrees C but was unstable at higher temperature (65 degrees C). The activation energy of the enzyme in reverse micelles was 46.5 +/- 2.6 kJ/mol, which was about 20 kJ/mol higher than that in aqueous solution and reflected in the lower Kcat value at low omega O. The binding affinity between the substrate 4-nitrophenyl phosphate and the enzyme in reverse micelles was decreased as implemented by the higher Km and higher Ki for phosphate values. In aqueous solution, the log kcat/pH plot suggested that amino acid residues with pKa values of 9.03 +/- 0.03 and 11.37 +/- 0.10 are involved in catalysis. The former should be deprotonated and the latter should be protonated for the reaction to proceed. In reverse micelles, both the above-mentioned pKa values were detected. However, both groups have to deprotonated to give the optimum catalytic function. In aqueous solution, the enzyme's specificity was highly dependent on pH and buffer. The pKa value of the amino acid residues involved in substrate binding was found to be 8.69 +/- 0.07 in carbonate buffer, but changed to 9.80 +/- 0.06 in Tris buffer. Our results suggested that the rate-limiting step of the enzyme-catalyzed reaction may be changed from phosphate releasing in aqueous solution to another critical step in the reverse micelles.
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Affiliation(s)
- G G Chang
- Department of Biochemistry, National Defense Medical Center, Taipei, Taiwan, Republic of China
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38
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Perez-Gilabert M, Sanchez-Ferrer A, Garcia-Carmona F. Application of active-phase plot to the kinetic analysis of lipoxygenase in reverse micelles. Biochem J 1992; 288 ( Pt 3):1011-5. [PMID: 1281978 PMCID: PMC1131988 DOI: 10.1042/bj2881011] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A new plot for explaining the complex expression of the enzymic activity in reverse micelles has been developed as an extension of the theoretical model described by our group [Bru, Sánchez-Ferrer & García-Carmona (1990) Biochem. J. 268, 679-684]. The plot describes the changes in the relative volume, amount of enzyme (mumoles), enzyme concentration (microM) and substrate concentration (microM) in the phase where the enzyme is active. To illustrate the usefulness of this plot, the complex activity of soya bean lipoxygenase in reverse micelles acting on its interfacial substrate, octadecadienoic acid, was studied. It showed the key parameters ruling the activity profiles of lipoxygenase with respect to micelle size (omega 0), micelle concentration (theta) and the substrate/surfactant molar ratio (rho), which have never been described before.
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Affiliation(s)
- M Perez-Gilabert
- Departamento de Bioquímica, Facultad de Biología, Universidad de Murcia, Spain
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39
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40
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CHOPINEAU JOËL, OLLIVON MICHEL, LEGOY MARIEDOMINIQUE. Enzyme Activity in Microstructured Media. Ann N Y Acad Sci 1992. [DOI: 10.1111/j.1749-6632.1992.tb35671.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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41
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Pshezhetsky AV, Levashov AV, Wiederschain GYa. Regulation of the GM1-galactosidase supramolecular structure and catalytic activity in vitro. BIOCHIMICA ET BIOPHYSICA ACTA 1992; 1122:154-60. [PMID: 1643088 DOI: 10.1016/0167-4838(92)90318-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Regulation of the supramolecular organization and the catalytic activity of GM1-galactosidase (EC 3.2.1.23) and neuraminidase (EC 3.2.1.18) from human kidney was studied in a system of hydrated reversed micelles of Aerosol OT in octane. It was shown that both the catalytic activity and the oligomeric structure of the GM1-galactosidase in reversed micelles depend on the [H2O]/[Aerosol OT] molar ratio (w(o)). GM1-galactosidase 64-67 kDa monomers, 260 kDa tetramers, and 660 kDa octamers were obtained in systems with w(o) = 0-20, 25-30 and 30-40, respectively. The association of GM1-galactosidase monomers into an octamer results in the cooperative increase in enzymatic activity. 'Protective protein', a component of the GM1-galactosidase-neuraminidase native complex, was found to improve this association significantly.
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Affiliation(s)
- A V Pshezhetsky
- Belozersky Institute of Physico-Chemical Biology, Moscow State University, Russia
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42
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Sánchez-Ferrer A, García-Carmona F. Reverse vesicles as a new system for studying enzymes in organic solvents. Biochem J 1992; 285 ( Pt 2):373-6. [PMID: 1637328 PMCID: PMC1132796 DOI: 10.1042/bj2850373] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A new approach to the study of enzyme activity in organic solvents has been developed by using optically transparent reverse vesicles. Polyphenol oxidase was incorporated in an active form into the above ternary system formed by the non-ionic surfactant tetra(ethylene glycol) dodecyl ether/n-dodecane/water. The enzyme in this microenvironment, surprisingly, showed an apparent positive co-operativity which has never before been described either in aqueous solution or in reverse micelles. In addition, the Vmax. expressed was similar to that in water and twice that displayed in reverse micelles.
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Affiliation(s)
- A Sánchez-Ferrer
- Departamento de Bioquímica y Biología Molecular, Facultad de Biología, Universidad de Murcia, Spain
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43
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Garza-Ramos G, Fernández-Velasco DA, Ramírez L, Shoshani L, Darszon A, Tuena de Gómez-Puyou M, Gómez-Puyou A. Enzyme activation by denaturants in organic solvent systems with a low water content. EUROPEAN JOURNAL OF BIOCHEMISTRY 1992; 205:509-17. [PMID: 1315269 DOI: 10.1111/j.1432-1033.1992.tb16807.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The effect of urea and guanidine hydrochloride (GdmCl) on the activity of heart lactate dehydrogenase, glycerol-3-phosphate dehydrogenase, hexokinase, inorganic pyrophosphatase, and glyceraldehyde-3-phosphate dehydrogenase was studied in low-water systems. Most of the experiments were made in a system formed with toluene, phospholipids, Triton X-100, and water in a range that varied over 1.0-6.5% (by vol.) [Garza-Ramos, G., Darszon, A., Tuena de Gómez-Puyou, M. & Gómez-Puyou, A. (1990) Biochemistry 29, 751-757]. In such conditions at saturating substrate concentrations, the activity of the enzymes was more than 10 times lower than in all-water media. However the activity of the first four aforementioned enzymes was increased between 4 and 20 times by the denaturants. The most marked activating effect was found with lactate dehydrogenase; with 3.8% (by vol.) water maximal activation was observed with 1.5 M GdmCl (about 20-fold); 4 M urea activated, but to a lower extent. Activation by guanidine thiocyanate was lower than with GdmCl. The activating and inactivating effects of GdmCl on lactate dehydrogenase depended on the amount of water; as the amount of water was increased from 2.0% to 6.0% (by vol.), activation and inactivation took place with progressively lower GdmCl concentrations. When activity was measured as a function of the volume of 1.5 M GdmCl solution, a bell-shaped activation curve was observed. In a low-water system formed with n-octane, hexanol, cetyltrimethylammonium bromide and 3.0% water, a similar activation of lactate dehydrogenase by GdmCl and urea was observed. The water solubility diagrams were modified by GdmCl and urea, and this could reflect on enzyme activity. However, from a comparison of denaturant concentrations on the activity of the enzymes studied, it would seem that, independently of their effect on the characteristics of the low-water systems, denaturants bring about activation through their known mechanism of action on the protein. It is suggested that the effect of denaturants is due to the release of constraints in enzyme catalysis imposed by a low-water environment.
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Affiliation(s)
- G Garza-Ramos
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México
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44
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Protein-Interface Interactions in Reverse Micelles. ACTA ACUST UNITED AC 1992. [DOI: 10.1016/b978-0-444-89046-7.50033-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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45
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Pshezhetsky AV, Buneeva OA, Dvorkin VM. Human kidney hexosaminidase A and hexosaminidase B form a complex. EUROPEAN JOURNAL OF BIOCHEMISTRY 1991; 202:361-5. [PMID: 1836996 DOI: 10.1111/j.1432-1033.1991.tb16383.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The isolation and purification of human kidney hexosaminidases A and B was carried out. Regulation of the supramolecular organization and catalytic activity of hexosaminidases was investigated in the bis(2-ethylhexyl)sulphosuccinate reversed micellar system modeling the enzyme microenvironment in the lysosomes. It was shown that hexosaminidases A and B associate forming 280-300-kDa dimeric complexes under these conditions. At pH 4.75, the hexosaminidases A and B can be isolated from kidney tissue only in the form of this complex.
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46
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Pshezhetsky AV, Buneeva OA, Wiederschain GYa. Solubilization of rat kidney lysosomes in reversed micelles of aerosol OT in octane. FEBS Lett 1991; 287:219-22. [PMID: 1715286 DOI: 10.1016/0014-5793(91)80055-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Intact lysosomes from rat kidneys were solubilized in the ternary system: surfactant (Aerosol OT)-buffer-organic solvent. According to data of laser light-scattering analysis and kinetic experiments with the lysosomal marker enzyme, N-acetyl-beta-D-hexosaminidase (EC 3.2.1.30), the solubilization of lysosomes in this system resulted in the destruction of the lysosomes and the entrapping of their components in reversed micelles.
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47
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Desfosses B, Cittanova N, Urbach W, Waks M. Ligand binding at membrane mimetic interfaces. Human serum albumin in reverse micelles. EUROPEAN JOURNAL OF BIOCHEMISTRY 1991; 199:79-87. [PMID: 1712302 DOI: 10.1111/j.1432-1033.1991.tb16094.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The behaviour of human serum albumin in the presence of three chemically distinct ligands: oxyphenylbutazone, dansylsarcosine and hemin, has been compared in buffer and in reverse micelles of isooctane, water, and either sodium bis(2-ethylhexyl)sulfosuccinate or hexadecyl trimethylammonium bromide, systems selected to mimic the membrane-water interface. Upon micellar incorporation, the dansylsarcosine-albumin complex dissociated, as evidenced by fluorescence emission spectroscopy (red shift from 485 nm to 570 nm) and by fluorescence polarization measurements. In contrast, the hemin-albumin complex remained stable in reverse micelles, as judged from the Soret absorption band at 408 nm and the molar absorption coefficient of 8.4 x 10(4) M-1 cm-1. The oxyphenylbutazone to albumin binding curves reveal that while the association constant remained unchanged (Ka approximately 1.0 x 10(5) M-1), only a fraction of the albumin molecules present reacted with the ligand. The results were unaffected by the nature and the concentration of the surfactant. These findings can be interpreted in the light of conformational changes induced in human serum albumin by the large micellar inner surface area. The blue shift of the fluorescence emission maximum from 344 nm in buffer to 327 nm in sodium bis(2-ethylhexyl)sulfosuccinate micelles and the lesser reactivity/accessibility of the fluorophore to oxidation by N-bromosuccinimide, indicate perturbations of the sole tryptophan-214 microenvironment. However, the distance between the indole residue and tyrosine-411 does not seem substantially modified by the 15% decrease affecting the alpha helices of the albumin molecule. It is proposed that the results reported herein reflect the interactions of albumin with a membrane-like interface which generates two protein subpopulations differing in their membrane-surface and ligand affinities. Overall and local conformational changes, originating from this surface-induced effect, may thus constitute a ligand-release facilitating mechanism acting at cellular membrane levels.
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Affiliation(s)
- B Desfosses
- Unité de Formation et de Recherches Biomédicale des Saints Pères, Université René Descartes, Paris, France
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48
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Karpe P, Ruckenstein E. The enzymatic superactivity in reverse micelles: Role of the dielectric constant. J Colloid Interface Sci 1991. [DOI: 10.1016/0021-9797(91)90350-h] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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49
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50
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Bianucci M, Maestro M, Walde P. Bell-shaped curves of the enzyme activity in reverse micelles: A simplified model for hydrolytic reactions. Chem Phys 1990. [DOI: 10.1016/0301-0104(90)87063-h] [Citation(s) in RCA: 13] [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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