Effects of Mutations on the Reconfiguration Rate of α-Synuclein

Autor: Lisa J. Lapidus, Srabasti Acharya, Basir Ahmad, Shreya Saha
Rok vydání: 2015
Předmět:
Zdroj: The Journal of Physical Chemistry B. 119:15443-15450
ISSN: 1520-5207
1520-6106
DOI: 10.1021/acs.jpcb.5b10136
Popis: It is still poorly understood why α-synuclein, the intrinsically disordered protein involved in Parkinson’s and other neurodegenerative diseases, is so prone to aggregation. Recent work has shown a correlation between the aggregation rate and the rate of diffusional reconfiguration by varying temperature and pH. Here we examine the effects of several point mutations in the sequence on the conformational ensemble and reconfiguration rate. We find that at lower temperatures the PD causing aggregation enhancing mutations slow down and aggregation reducing mutations drastically speed up intramolecular diffusion, as compared to the wild type sequence. However, at higher temperatures, one of three familial mutations that enhance aggregation slows intramolecular diffusion while non-natural mutations that inhibit aggregation speed up intramolecular diffusion. These results support the hypothesis that the first step of aggregation is kinetically controlled by reconfiguration in which the protein chain cannot reconfigure rapidly enough to escape oligomerization. Finally we provide physical and chemical insights into why small point mutations cause these dramatic changes in the conformational ensemble and dynamics.
Databáze: OpenAIRE