Effects of site-directed PEGylation on L-asparaginase thermostability (2021)
- Authors:
- Autor USP: CUNHA, JHENIFFER RABELO - FCF
- Unidade: FCF
- Sigla do Departamento: FBT
- Subjects: TERMODINÂMICA; ENZIMAS
- Keywords: Bioconjugação; Bioconjugation; Enzimas; Enzyme thermostability; Enzymes; N-terminal PEGylation; PEGuilação N-terminal; Termo-inativação; Termodinâmica; Termoestabilidade; Thermo-inactivation; Thermodynamics
- Agências de fomento:
- Language: Inglês
- Abstract: The enzyme L-asparaginase (ASNase) is broadly applied as a drug to treat acute lymphoblastic leukemia, as well as in the food industry to avoid acrylamide formation in baked and fried food. In the present work, ASNase was covalently attached to polyethylene glycol (PEG) of different molecular weights (ASNase-PEG-5, ASNase-PEG-10, ASNase-PEG-20, and ASNase-PEG-40) at the N-terminal portion (monoPEGylation). Native and PEGylated forms were analyzed regarding thermodynamics and thermostability based on enzyme activity measurements. ASNase (native and PEGylated) presented maximum activity at 40 °C and denaturation followed a first-order kinetics. Based on these results, the activation energy for denaturation (‘E POT.* ’‘ANTIND. d’) was estimated and higher values were observed for PEGylated forms compared to the native ASNase, highlighting the ASNase-PEG10 with a 4.24-fold increase (48.85 kJ. ‘mol POT.-1’) in comparison to the native form (11.52 kJ. ‘mol POT.-1’). The enzymes were evaluated by residual activity over time (21 days) under different storage temperatures (4 and 37 °C) and the PEGylated conjugates remained stable after the 21 days. Thermodynamic parameters like enthalpy (‘ΔH POT.‡’) de desnaturação irreversível foram analisados. Valores maiores - e ), entropy (‘ΔS POT.‡’) de desnaturação irreversível foram analisados. Valores maiores - e ) and Gibbs free energy (‘ΔG POT.‡’) de desnaturação irreversível foram analisados. Valores maiores - e ) of ASNase (native and PEGylated) irreversible denaturation were also investigated. Higher - and positive - values of Gibbs free energy were found for the PEGylated conjugates (61.21 a 63.45 kJ. ‘mol POT.-1’), indicating that the process of denaturation was not spontaneous. Enthalpy also was higher for PEGylated conjugates (18.84 a 46.08 kJ. ‘mol POT.-1’), demonstrating the protective role of PEGylation. As forentropy, the negative values were more elevated for native ASNase (-0.149 J/mol.K), pointing out that the denaturation process enhanced the randomness and aggregation of the system, which was observed by circular dichroism. Thus, PEGylation proved its potential to increase ASNase thermostability
- Imprenta:
- Data da defesa: 22.03.2021
-
ABNT
CUNHA, Jheniffer Rabelo. Effects of site-directed PEGylation on L-asparaginase thermostability. 2021. Dissertação (Mestrado) – Universidade de São Paulo, São Paulo, 2021. Disponível em: https://www.teses.usp.br/teses/disponiveis/9/9135/tde-05082021-101113/. Acesso em: 23 maio 2024. -
APA
Cunha, J. R. (2021). Effects of site-directed PEGylation on L-asparaginase thermostability (Dissertação (Mestrado). Universidade de São Paulo, São Paulo. Recuperado de https://www.teses.usp.br/teses/disponiveis/9/9135/tde-05082021-101113/ -
NLM
Cunha JR. Effects of site-directed PEGylation on L-asparaginase thermostability [Internet]. 2021 ;[citado 2024 maio 23 ] Available from: https://www.teses.usp.br/teses/disponiveis/9/9135/tde-05082021-101113/ -
Vancouver
Cunha JR. Effects of site-directed PEGylation on L-asparaginase thermostability [Internet]. 2021 ;[citado 2024 maio 23 ] Available from: https://www.teses.usp.br/teses/disponiveis/9/9135/tde-05082021-101113/
How to cite
A citação é gerada automaticamente e pode não estar totalmente de acordo com as normas
