Impact of the PEG length and PEGylation site on the structural, thermodynamic, thermal and proteolytic stability of mono-PEGylated alpha-1 antitrypsin
(2022) Protein Science — Vol. 31, p. e4392 (2022)
Files
LiuetalProtScaccepted.pdf
Open Access - Adobe PDF
- 2.52 MB
Details
- Authors
- Abstract
- Conjugation to polyethylene glycol (PEG) is a widely used approach to improve the therapeutic value of proteins essentially by prolonging their body residence time. PEGylation may however induce changes in the structure and/or the stability of proteins and thus on their function(s). The effects of PEGylation on the thermodynamic stability can either be positive (stabilization), negative (destabilization) or neutral (no effect). Moreover, various factors such as the PEG length and PEGylation site can influence the consequences of PEGylation on the structure and stability of proteins. In this study, the effects of PEGylation on the structure, stability and polymerization of alpha1-antitrypsin (AAT) were investigated, using PEGs with different lengths, different structures (2- armed or not) and different linking chemistries (via amine or thiol) at two distinct positions of the sequence. The results obtained show that whatever the size, position, and structure of PEG chains, PEGylation (i) does not induce significant changes in AAT structure (either at the secondary or tertiary level); (ii) does not alter the stability of the native protein upon both chemical- and heat-induced denaturation; and (iii) does not prevent AAT to fully refold and recover its activity following chemical denaturation. However, the propensity of AAT to aggregate upon heat treatment was significantly decreased by PEGylation, although PEGylation does not prevent the irreversible inactivation of the enzyme. PEGylation greatly improved the proteolytic resistance of AAT. Overall, AAT stability came out largely affected by the nature of the applied stresses and less affected by conjugation to PEG and PEG properties.
- Affiliations
Citations
Liu, X., Kouassi, K., Vanbever, R., & Dumoulin, M. (2022). Impact of the PEG length and PEGylation site on the structural, thermodynamic, thermal and proteolytic stability of mono-PEGylated alpha-1 antitrypsin. Protein Science, 31, e4392. https://hdl.handle.net/2078.5/240571 (Original work published 2022)