Determinação de parâmetros estruturais e termodinâmicos da isoforma a-tripsina bovina em solventes aquo-orgânicos

• Autor(a) principal: Rosa, Dayanne Pinho
• Data de Publicação: 2017
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Espírito Santo (riUfes)
• Texto Completo: http://repositorio.ufes.br/handle/10/7866
• topic: Farmacologia Bioquímica e Molecular; Tripsina; Enzimas; Termodinâmica; Proteínas; 61

Organic solvents are common in industrial processes that use enzymes but, at the same time, it is known that they change the properties thereof, thus the effects of aqueous-organic solvent (ethanol) in different concentration on the α-trypsin structure have been investigated by spectroscopic techniques and thermodynamic data analysis. The results from spectroscopic measurements, including far-UV Circular Dichroism, UV-Vis absorption spectroscopy, intrinsic tryptophan fluorescence and dynamic light scattering (DLS) suggest the formation of partially folded states, instead of aggregates states, at high ethanol concentration (> 60% v/v ethanol), with little loss of secondary structure, but with significant tertiary structure changes. The thermodynamic data (Tm and ∆H) suggest a loosen of intramolecular weak interactions, which reflects in a flexibility increase such that the catalytic capacity can be increased or decreased according to the ethanol concentration into the system. Overall results we suggest that in range of 0-60% v/v ethanol/buffer, α-trypsin undergoes reversible multimerization phenomena maintaining its catalytic activity. However from 60% v/v ethanol/buffer, population of folded partially states with less catalytic activity are predominant.