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Published on: November 21, 2017
Differences in the effects of solution additives on heat- and refolding-induced aggregation
Hiroyuki Hamada1, Ryouta Takahashi, Takumi Noguchi
1Institute of Applied Physics, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, Japan.
Biotechnology Progress
|April 5, 2008
Summary
Low-molecular-weight additives show varied effects on protein aggregation. Guanidine, arginine, and spermidine differentially impact heat- and refolding-induced aggregation, influenced by their interaction with protein surfaces.
Area of Science:
- Biochemistry
- Protein Science
- Chemical Engineering
Background:
- Protein aggregation is a significant challenge in biotechnology and medicine.
- Low-molecular-weight additives are explored to mitigate protein aggregation.
- The differential effects of these additives on various aggregation pathways remain unclear.
Purpose of the Study:
- To investigate and compare the effects of guanidine (Gdn), arginine (Arg), and spermidine (Spd) on heat- and refolding-induced protein aggregation.
- To elucidate the mechanisms underlying the observed differences in additive efficacy.
- To correlate additive-protein interactions with aggregation suppression.
Main Methods:
- Comparative analysis of aggregation suppression by Gdn, Arg, and Spd under thermal and oxidative refolding conditions.
- Lysozyme solubility assays to assess additive effects on protein stability.
- Thermal unfolding experiments to probe protein conformational changes and additive interactions.
Main Results:
- Guanidine (Gdn) did not suppress thermal aggregation but enhanced oxidative refolding yields.
- Spermidine (Spd) effectively suppressed heat-induced aggregation but promoted aggregation during oxidative refolding.
- Arginine (Arg) demonstrated efficacy in suppressing both heat- and refolding-induced aggregation.
- Lysozyme solubility and unfolding data indicated preferential exclusion of Spd from native proteins, while Gdn and Arg solubilized refolding intermediates.
Conclusions:
- The efficacy of low-molecular-weight additives in protein aggregation suppression is process-specific.
- Additive interactions with protein surfaces, including preferential exclusion or solubilization of intermediates, dictate their impact on aggregation.
- Understanding these specific interactions is crucial for designing effective protein stabilization strategies.
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