Transient Diffusive Interactions with a Protein Crowder Affect Aggregation Processes of Superoxide Dismutase 1 β-Barrel

Autor: Kenji Sugase, Masahiro Shirakawa, Daichi Morimoto, Erik Walinda, Sarah Leeb, Jens Danielsson, Naoto Iwakawa
Rok vydání: 2021
Předmět:
Zdroj: The Journal of Physical Chemistry B. 125:2521-2532
ISSN: 1520-5207
1520-6106
Popis: Aggregate formation of superoxide dismutase 1 (SOD1) inside motor neurons is known as a major factor in onset of amyotrophic lateral sclerosis. The thermodynamic stability of the SOD1 β-barrel has been shown to decrease in crowded environments such as inside a cell, but it remains unclear how the thermodynamics of crowding-induced protein destabilization relate to SOD1 aggregation. Here we have examined the effects of a protein crowder, lysozyme, on fibril aggregate formation of the SOD1 β-barrel. We found that aggregate formation of SOD1 is decelerated even in mildly crowded solutions. Intriguingly, transient diffusive interactions with lysozyme do not significantly affect the static structure of the SOD1 β-barrel but stabilize an alternative excited "invisible" state. The net effect of crowding is to favor species off the aggregation pathway, thereby explaining the decelerated aggregation in the crowded environment. Our observations suggest that the intracellular environment may have a similar negative (inhibitory) effect on fibril formation of other amyloidogenic proteins in living cells. Deciphering how crowded intracellular environments affect aggregation and fibril formation of such disease-associated proteins will probably become central in understanding the exact role of aggregation in the etiology of these enigmatic diseases.
Databáze: OpenAIRE