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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

PEGylation as an efficient tool to enhance cytochrome c thermostability: a kinetic and thermodynamic study

Texto completo
Autor(es):
Santos, Joao H. P. M. [1, 2] ; Carretero, Gustavo [3] ; Ventura, Sonia P. M. [2] ; Converti, Attilio [4] ; Rangel-Yagui, Carlota O. [1]
Número total de Autores: 5
Afiliação do(s) autor(es):
[1] Univ Sao Paulo, Dept Biochem & Pharmaceut Technol, BR-05508000 Sao Paulo - Brazil
[2] Univ Aveiro, Dept Chem, CICECO Aveiro Inst Mat, P-3810193 Aveiro - Portugal
[3] Univ Sao Paulo, Inst Chem, Dept Biochem, BR-05508000 Sao Paulo - Brazil
[4] Genoa Univ, Pole Chem Engn, Dept Civil Chem & Environm Engn, Via Opera Pia 15, I-16145 Genoa - Italy
Número total de Afiliações: 4
Tipo de documento: Artigo Científico
Fonte: JOURNAL OF MATERIALS CHEMISTRY B; v. 7, n. 28, p. 4432-4439, JUL 28 2019.
Citações Web of Science: 0
Resumo

Cytochrome-c from equine heart was kinetically and thermodynamically investigated either in its native (Cyt-c) or PEGylated forms with different PEGylation degrees (Cyt-c-PEG-4 and Cyt-c-PEG-8). Maximum activities were observed at 80 degrees C, and the irreversible deactivation was well described by first-order kinetics. The results of activity at different temperatures were used to estimate the activation energy of the catalysed Cyt-c reaction (E{*} = 10.22 +/- 0.40, 7.51 +/- 0.06 and 8.87 +/- 0.29 kJ mol(-1) for Cyt-c, Cyt-c-PEG-4 and Cyt-c-PEG-8) and the standard enthalpy variation of enzyme unfolding ( = 33.82 +/- 4.92, 109.4 +/- 13.1 and 58.43 +/- 3.11 kJ mol(-1) for Cyt-c, Cyt-c-PEG-4 and Cyt-c-PEG-8, respectively). The results of residual activity tests allowed estimating the activation energy (E-d{*} = 50.51 +/- 1.71, 72.63 +/- 0.89 and 63.36 +/- 1.66 kJ mol(-1) for Cyt-c, Cyt-c-PEG-4 and Cyt-c-PEG-8), enthalpy (Delta H-double dagger), entropy (Delta S-double dagger) and Gibbs free energy (Delta G(double dagger)) of the enzyme irreversible denaturation. The higher enthalpic contributions of PEGylated conjugates and the increase in Delta G(double dagger), compared to the native protein, indorsed the protective role of PEGylation. Negative values of Delta S-double dagger suggested the occurrence of an aggregation phenomenon by increasing the temperature, which was confirmed by circular dichroism. The estimated thermodynamic parameters suggest that PEGylated Cyt-c forms have enhanced thermostability, which would be of great significance for industrial biosensing applications. (AU)

Processo FAPESP: 16/22065-5 - Pegilação N-terminal de proteínas e purificação por sistemas aquosos bifásicos
Beneficiário:Carlota de Oliveira Rangel Yagui
Linha de fomento: Auxílio à Pesquisa - Regular