Determination of structural and thermodynamic parameters of bovine α-trypsin isoform in aqueous-organic media
| Autor: | Alexandre Martins Costa Santos, Dayanne Pinho Rosa, Jamil S. Oliveira, Evaldo Vitor Pereira, Marcelo M. Santoro, M.A. Cicilini, André Romero da Silva, Juliana Barbosa Coitinho, Caroline Dutra Lacerda, Antonio Victor Baioco Vasconcelos |
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| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Circular dichroism Globular protein Population Biochemistry Protein Structure Secondary 03 medical and health sciences Dynamic light scattering Structural Biology Enzyme Stability Animals Organic chemistry Trypsin education Molecular Biology Protein secondary structure chemistry.chemical_classification education.field_of_study Aqueous solution Dose-Response Relationship Drug Ethanol Water General Medicine Protein tertiary structure Isoenzymes Solvent Crystallography 030104 developmental biology chemistry Biocatalysis Thermodynamics Cattle |
| Zdroj: | International Journal of Biological Macromolecules. 101:408-416 |
| ISSN: | 0141-8130 |
| DOI: | 10.1016/j.ijbiomac.2017.03.125 |
| Popis: | The α-trypsin isoform is a globular protein that belongs to serine-protease family and has a polypeptide chain of 223 amino acid residues, six disulfide bridges and two domains with similar structures. 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 aggregate 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 ΔH) suggest a loosening 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 with catalytic activity. However from 60% v/v ethanol/buffer, population of folded partially states with less catalytic activity are predominant. |
| Databáze: | OpenAIRE |
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