Partição dos aminoacidos L-fenilalanina, L-tirosina e L-triptofano, e da proteina insulina humana, em sistemas aquosos bifasicos contendo polimeros, copolimeros e sais

AUTOR(ES)
DATA DE PUBLICAÇÃO

2000

RESUMO

The partitioning between two aqueous phases, containing each phase ftom 70 to 90% of water, is considered a suitable and an appropriate technique for the purification of iomolecules like amino acids and proteins. This partitioning depends on different factors like pH, polymer molecular weight and temperature. Recently, the use of some types of copolymer PEO-PPO-PEO has been suggested in the formation of these systems. The increase in temperature origin the auto-aggregation of copolymers in micelles and the redistribution of the water molecules of the phase containing these copolymers, forming means which characteristics are ideaIs for a separation of hydrophobic biomolecules. The objective of this work was to obtain experimental data on the equilibrium behavior and partitioning of the amino acids L- Tryptophane, L-Phenylalanine and LTyrosine, and the protein Human Insulin, in Aqueous Two-Phase Systems (ATPS) containing polymers PEG4600 and PEGlOOOO, copolymers F38, F68 and F88 and salts such as monobasic and dibasic potassium phosphate, in order to identify the thermodynamics variables that influence on the biomolecules partitioning in these systems. The partitioning experiments were organized and carried out according to a Factorial Design Plan, evaluating the influence of the variables temperature (10, 25 and 40°C), pH ( 5, 7 and 9) and molecular weight of the polymer and copolymer in the biomolecules partition coefficients studied. Results showed that amino acids partitioning was influenced by pH and temperature. L-Tryptophane presented the highest partition coefficient (K=2,8) in comparison to other amino acids studied due to its higher hydrophobicity. The partition of the Human Insulin was also influenced by the temperature and pH. Human Insulin partition was found to be successful (K=22) which could be attributed to the use of copolymers blocks. The equilibrium behavior of these ATPS showed an increase in the two-phase region with the increase of the dibasic phosphate salt concentration due to the pH incremento Also was observed that the global composition of the system influence the partition coefficient, obtaining an increase the K values with the increasing of the tie line lengths, meaning an increasing in the copolymer proportion in the system

ASSUNTO(S)

polimeros particionamento aminoacidos insulina planejamento experimental equilibrio liquido-liquido

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