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Falcone RD, Biasutti MA, Correa NM, Silber JJ, Lissi E, Abuin E. Effect of the addition of a nonaqueous polar solvent (glycerol) on enzymatic catalysis in reverse micelles. Hydrolysis of 2-naphthyl acetate by alpha-chymotrypsin. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2004; 20:5732-7. [PMID: 16459586 DOI: 10.1021/la036243x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The kinetics of hydrolysis of 2-naphthyl acetate (2-NA) catalyzed by alpha-chymotrypsin (alpha-CT), in reverse micellar solutions formed by glycerol (GY)-water (38% v/v) mixture/sodium bis(2-ethylhexyl)sulfosuccinate (AOT)/n-heptane has been determined by spectroscopic measurements. To compare the efficiency of this reaction with that observed in micelles with water in the core, as well as in the corresponding homogeneous media, the reaction was also studied in water/AOT/n-heptane reverse micellar solutions and in both homogeneous media (water and GY-water, 38% v/v mixture). In every media, alpha-CT was characterized by the absorption and emission spectra, the fluorescence lifetimes, and the fluorescence anisotropy of its tryptophan residues. The effect of AOT concentration on the kinetic parameters obtained in the micellar systems was determined, at a constant molar ratio of the inner polar solvent and surfactant. Moreover, the data obtained allowed the evaluation of the 2-NA partition constant between the organic and the micellar pseudophase. It is shown that the addition of GY to the micelle interior results in an increase in the catalytic properties of alpha-CT. The fluorescence anisotropy studies in the different media show that the addition of GY increases the viscosity as compared with the aqueous systems. It seems that the GY addition to the reverse micellar aggregates results in a decrease of the conformational mobility of alpha-CT, which leads to an increase of the enzyme stability and activity.
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Affiliation(s)
- R Darío Falcone
- Departamento de Química, Universidad Nacional de Río Cuarto, Agencia Postal N 3 (5800) Río Cuarto, Argentina
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Munshi N, De TK, Maitra A. Size Modulation of Polymeric Nanoparticles under Controlled Dynamics of Microemulsion Droplets. J Colloid Interface Sci 1997; 190:387-91. [PMID: 9241182 DOI: 10.1006/jcis.1997.4889] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Polyacrylamide nanoparticles of different size (<100 nm) were prepared in reverse micelles under various dynamic conditions of micellar systems. The nanoparticles were always larger than the aqueous core in which they were formed; however, the size of the nanoparticles could be controlled if the interdroplet interaction and coalescence rate in reverse micelles were regulated. Factors such as interfacial rigidity of the droplets, size of the aqueous core, temperature, and concentrations of acrylamide (monomer) and N ,N '-methylenebisacrylamide (crosslinking agent) have a profound effect on the size of nanoparticles. By adjustment of these parameters in reverse micelles, nanoparticles ranging from about 10 to more than 100 nm have been prepared.
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Affiliation(s)
- N Munshi
- Department of Chemistry, University of Delhi, Delhi, 110 007, India
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Meziani A, Touraud D, Zradba A, Pulvin S, Pezron I, Clausse M, Kunz W. Comparison of Enzymatic Activity and Nanostructures in Water/Ethanol/Brij 35 and Water/1-Pentanol/Brij 35 Systems. J Phys Chem B 1997. [DOI: 10.1021/jp963024u] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- A. Meziani
- Département Génie Chimique, URA CNRS 1888, Université de Technologie de Compiègne, B.P 529, F-60 205 Compiègne Cedex, France, and Département Génie Biologique, Laboratoire de Technologie Enzymatique, URA CNRS 1442, Université de Technologie de Compiègne, B.P 529, F-60 205 Compiègne Cedex, France
| | - D. Touraud
- Département Génie Chimique, URA CNRS 1888, Université de Technologie de Compiègne, B.P 529, F-60 205 Compiègne Cedex, France, and Département Génie Biologique, Laboratoire de Technologie Enzymatique, URA CNRS 1442, Université de Technologie de Compiègne, B.P 529, F-60 205 Compiègne Cedex, France
| | - A. Zradba
- Département Génie Chimique, URA CNRS 1888, Université de Technologie de Compiègne, B.P 529, F-60 205 Compiègne Cedex, France, and Département Génie Biologique, Laboratoire de Technologie Enzymatique, URA CNRS 1442, Université de Technologie de Compiègne, B.P 529, F-60 205 Compiègne Cedex, France
| | - S. Pulvin
- Département Génie Chimique, URA CNRS 1888, Université de Technologie de Compiègne, B.P 529, F-60 205 Compiègne Cedex, France, and Département Génie Biologique, Laboratoire de Technologie Enzymatique, URA CNRS 1442, Université de Technologie de Compiègne, B.P 529, F-60 205 Compiègne Cedex, France
| | - I. Pezron
- Département Génie Chimique, URA CNRS 1888, Université de Technologie de Compiègne, B.P 529, F-60 205 Compiègne Cedex, France, and Département Génie Biologique, Laboratoire de Technologie Enzymatique, URA CNRS 1442, Université de Technologie de Compiègne, B.P 529, F-60 205 Compiègne Cedex, France
| | - M. Clausse
- Département Génie Chimique, URA CNRS 1888, Université de Technologie de Compiègne, B.P 529, F-60 205 Compiègne Cedex, France, and Département Génie Biologique, Laboratoire de Technologie Enzymatique, URA CNRS 1442, Université de Technologie de Compiègne, B.P 529, F-60 205 Compiègne Cedex, France
| | - W. Kunz
- Département Génie Chimique, URA CNRS 1888, Université de Technologie de Compiègne, B.P 529, F-60 205 Compiègne Cedex, France, and Département Génie Biologique, Laboratoire de Technologie Enzymatique, URA CNRS 1442, Université de Technologie de Compiègne, B.P 529, F-60 205 Compiègne Cedex, France
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