Estabilidade térmica de proteínas na presença de líquidos iónicos
Miniatura indisponível
Data
2017
Título da revista
ISSN da revista
Título do Volume
Editora
Resumo
As proteínas são biomoléculas que apresentam um grande potencial farmacológico. No entanto, são também conhecidas pela sua instabilidade quando expostas a determinadas condições, como alterações à temperatura e pH ótimos, que podem comprometer a sua utilização em formulações farmacêuticas.
Neste contexto, a procura de alternativas que auxiliem a estabilidade destas moléculas é uma constante, e a adição de determinados co-solventes pode representar uma solução. Neste trabalho experimental, foi estudada a estabilidade térmica de proteínas, utilizando três líquidos iónicos (LI) como potenciais co-solventes estabilizadores. Como proteína modelo utilizou-se a lisozima, e os líquidos iónicos estudados foram o Brometo de 1-hexil-3-Metilimidazolio – [C6mim][Br], que pertence aos derivados de imidazol, o (2-Hidroxietil)-trimetilamonio-L-fenilalaninato – [Cho][[Phe] – e o (2-Hidroxietil)-trimetilamonio-L-glutamato – [Cho][Glu], que pertencem aos derivados de colina.
Foram realizados ensaios de estabilidade onde várias soluções de lisozima contendo LI foram expostas a diferentes temperaturas, nomeadamente 60 °C e 90 °C, durante diferentes intervalos de tempo. Os resultados demonstram, tal como esperado, que a lisozima perde atividade sempre que é exposta a temperaturas elevadas, no entanto em soluções que contêm LI apresentam taxas de recuperação de atividade enzimática mais elevadas do que na ausência dos mesmos.
Em conclusão, os resultados obtidos mostram que a utilização de LI como co-solventes estabilizadores de proteínas é promissor, embora sejam necessários mais estudos para reconhecer as propriedades físico-químicas dos LI que melhor auxiliam a estabilidade proteica.
Proteins are biomolecules that present a great pharmacological potential. However, they are also known for their instability when exposed to certain conditions, such as alterations to the optimal temperature and pH, which may compromise their use in pharmaceutical formulations. Thus, the search for alternatives that help the stability of these molecules is a constant, and the addition of co-solvents may represent a solution. In this experimental work, the thermal stability of proteins was studied, using three ionic liquids as potential stabilizing co-solvents. As the model protein used was lysozyme and the ionic liquids (IL) studied were 1-hexyl-3-methylimidazolium bromide [C6mim][Br], derived to imidazole derivatives, and two ionic liquids derived from choline, the (2-hydroxyethyl) -Trimethylammonium-L-phenylalaninate - [Cho][[Phe] - and the (2-Hydroxyethyl) -trimethylammonium-L-glutamate - [Cho][Glu]. Stability tests were performed where several solutions containing Lysozyme and IL were exposed at different temperatures, namely 60 °C and 90 °C, during different time intervals. The results demonstrate that, as expected, lysozyme loses activity whenever exposed to high temperatures. Nevertheless, solutions containing ILs have higher recovery rates of enzymatic activity than without the presence of these liquids. In conclusion, the results show that the use of ILs as protein stabilizing co-solvents is promising, although further studies are needed to recognize the physicochemical properties of the ILs that best aid protein stability.
Proteins are biomolecules that present a great pharmacological potential. However, they are also known for their instability when exposed to certain conditions, such as alterations to the optimal temperature and pH, which may compromise their use in pharmaceutical formulations. Thus, the search for alternatives that help the stability of these molecules is a constant, and the addition of co-solvents may represent a solution. In this experimental work, the thermal stability of proteins was studied, using three ionic liquids as potential stabilizing co-solvents. As the model protein used was lysozyme and the ionic liquids (IL) studied were 1-hexyl-3-methylimidazolium bromide [C6mim][Br], derived to imidazole derivatives, and two ionic liquids derived from choline, the (2-hydroxyethyl) -Trimethylammonium-L-phenylalaninate - [Cho][[Phe] - and the (2-Hydroxyethyl) -trimethylammonium-L-glutamate - [Cho][Glu]. Stability tests were performed where several solutions containing Lysozyme and IL were exposed at different temperatures, namely 60 °C and 90 °C, during different time intervals. The results demonstrate that, as expected, lysozyme loses activity whenever exposed to high temperatures. Nevertheless, solutions containing ILs have higher recovery rates of enzymatic activity than without the presence of these liquids. In conclusion, the results show that the use of ILs as protein stabilizing co-solvents is promising, although further studies are needed to recognize the physicochemical properties of the ILs that best aid protein stability.
Descrição
Orientação: Tânia Santos de Almeida
Palavras-chave
MESTRADO INTEGRADO EM CIÊNCIAS FARMACÊUTICAS, CIÊNCIAS FARMACÊUTICAS, FARMACOLOGIA, PROTEÍNAS, TEMPERATURA, PHARMACEUTICAL SCIENCES, PHARMACOLOGY, PROTEINS, TEMPERATURE, PH, PH, LÍQUIDOS IÓNICOS, IONIC LIQUIDS