Abstract
Accelerated progression rates in Parkinson’s disease (PD) have been linked to C-terminal domain (CTD) truncations of monomeric α-Synuclein (α-Syn), which have been suggested to increase amyloid aggregation in vivo and in vitro. In the brain of PD patients, CTD truncated α-Syn was found to have lower cell viability and tends to increase in the formation of fibrils. The CTD of α-Syn acts as a guard for regulating the normal functioning of α-Syn. The absence of the CTD may allow the N-terminal of α-Syn to interact with the membrane thereby affecting the normal functioning of α-Syn, and all of which will affect the etiology of PD. In this study, the conformational dynamics of CTD truncated α-Syn (1–99 and 1–108) monomers and their effect on the protein–membrane interactions were demonstrated using the all-atom molecular dynamics (MD) simulation method. From the MD analyses, it was noticed that among the two truncated monomers, α-Syn (1–108) was found to be more stable, shows rigidness at the N-terminal region and contains a significant number of intermolecular hydrogen bonds between the non-amyloid β-component (NAC) region and membrane, and lesser number of extended strands. Further, the bending angle in the N-terminal domain was found to be lesser in the α-Syn (1–108) in comparison with the α-Syn (1–99). Our findings suggest that the truncation on the CTD of α-Syn affects its interaction with the membrane and subsequently has an impact on the aggregation.
Communicated by Ramaswamy H. Sarma
Acknowledgments
The authors acknowledge Science and Engineering Research Board (SERB) for the financial grant. This study was supported by the project (EMR/2017/005383) under DST-SERB. DD thanks SERB for GATE JRF fellowship.
Disclosure statement
No potential conflict of interest was reported by the author(s).
Author contributions
The manuscript was written through contributions of all authors. All authors have given approval to the final version of the manuscript.