Otimização das condições para titulações potenciometricas de proteinas em soluções concentradas de ureia : titulações potenciometricas da proteina de Bence Jones (JJO)

AUTOR(ES)
DATA DE PUBLICAÇÃO

1986

RESUMO

In previous studies carried out in this laboratory involving acid-base titrations in concentrated urea solutions a large variation in the liquid junction potential and/or the activity coefficient of hydrogen ion has been observed during the tritation. In this investigation it tas been shown that such variations are dependent on the change in composition of the urea solution in the course of the titration. This change in composition of the urea solution dependes on the concentration of the titrant solution. Potentiometric titrations of the amino acid histidine and of the proteins lysozime and ovalbumin in concentrated urea solutions have been studied. The titrations have been performed in conditions that cause a low variation in the composition of the overall solution. Results obtained with ovalbumin agree quite weel with those obtained with more dilute titrants. A computer program involving the use of a more exact treatment than that employed previously in this laboratory has been used. With this more exact treatment it is possible to attain the maximum capability of separation of the program. Potentiometric titrations of Bence Jones (JJO) protein, both desnatured in urea and at pH 3, have also been performed.

ASSUNTO(S)

proteinas potenciometria ureia

ACESSO AO ARTIGO

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