Impact of supramolecular interactions of dextran‐β‐cyclodextrin polymers on invertase activity in freeze‐dried systems |
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| Authors: | Patricio R. Santagapita M. Florencia Mazzobre M. Pilar Buera Héctor L. Ramirez Leissy Gómez Brizuela Horacio R. Corti Reynaldo Villalonga |
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| Affiliation: | 1. Industry Dept., Faculty of Exact and Natural Sciences, University of Buenos Aires, Intendente Güiraldes 2160 ‐ Ciudad Universitaria ‐ C1428EGA (FCEyN‐UBA), Ciudad Autónoma de Buenos Aires, Argentina;2. Organic Chemistry Dept., Faculty of Exact and Natural Sciences, University of Buenos Aires, Intendente Güiraldes 2160 ‐ Ciudad Universitaria ‐ C1428EGA (FCEyN‐UBA), Ciudad Autónoma de Buenos Aires, Argentina;3. National Council of Scientific and Technical Research (CONICET), Ciudad Autónoma de Buenos Aires, Argentina;4. Center for Enzyme Technology, University of Matanzas, Cuba;5. Dept. de Física de la Materia Condensada, Comisión Nacional de Energía Atómica, Centro Atómico Constituyentes, Argentina;6. Inst. de Química Física de los Materiales, Ambiente y Energía (INQUIMAE), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Argentina;7. Dept. of Analytical Chemistry, Faculty of Chemistry, Complutense University of Madrid, Spain |
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| Abstract: | β‐Cyclodextrin (β‐CD)‐grafted dextrans with spacer arms of different length were employed to evaluate the impact of supramolecular interactions on invertase activity. The modified dextrans were used as single additives or combined with trehalose in freeze‐dried formulations containing invertase. Enzyme activity conservation was analyzed after freeze‐drying and thermal treatment. The change of glass transition temperature (Tg) was also evaluated and related to effective interactions. Outstanding differences on enzyme stability were mainly related to the effect of the spacer arm length on polymer–enzyme interactions, since both the degree of substitution and the molecular weight were similar for the two polymers. This change of effective interactions was also manifested in the pronounced reduction of Tg values, and were related to the chemical modification of the backbone during oxidation, and to the attachment of the β‐CD units with spacer arms of different length on dextran. © 2015 American Institute of Chemical Engineers Biotechnol. Prog., 31:791–798, 2015 |
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| Keywords: | supramolecular interactions dextran β ‐cyclodextrin glass transition temperature (Tg) enzyme stability |
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