Determination of Structural and Thermodynamic Parameters of Bovine #-trypsin Isoform in Aqueous-Organic Media
Name: DAYANNE PINHO ROSA
Type: MSc dissertation
Publication date: 23/02/2017
Advisor:
Name |
Role |
|---|---|
| ALEXANDRE MARTINS COSTA SANTOS | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| ALEXANDRE MARTINS COSTA SANTOS | Advisor * |
| PATRICIA MACHADO BUENO FERNANDES (M/D) | External Examiner * |
Summary: 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 -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, dinstead 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, -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.
