Oxidized EGCG redirects α-synuclein aggregation through shear-selected interactions
- 1Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University
Abstract
-Synuclein (Syn) aggregation is central to Parkinson's disease pathology, and the green-tea polyphenol epigallocatechin gallate (EGCG) has been studied as an inhibit fibril formation. However, EGCG autoxidation and analyses under static, non-fibrillating conditions have obscured whether activity arises from EGCG itself or oxidized species and which interactions persist during Syn assembly. Here we combine HPLC, LC-MS, TEM and solution NMR to compare unoxidized and oxidized EGCG (oxEGCG), while Rheo-NMR monitors Syn during shear-promoted assembly. Unoxidized EGCG showed no detectable binding under static, reducing conditions, whereas oxEGCG bound Syn, inhibited fibrillation and remodeled fibrils. Under shear flow, many oxEGCG-dependent perturbations partially reverted toward free Syn, whereas interactions near the NAC-C-terminal boundary were preferentially retained, coinciding with formation of oligomers and short, thick fibrils. These findings identify oxidation state and flow as determinants of EGCG action on Syn and show that Rheo-NMR distinguishes interactions that persist during shear-promoted assembly.
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BibTeX
@misc{yuen2026oxidized,
title = {{Oxidized EGCG redirects α-synuclein aggregation through shear-selected interactions}},
author = {C. M. Yuen and R. Yamaguchi and K. Uchida and Y. Shimada and Y. Shuto and S. Sakamoto and D. Morimoto and H. Ono and M. So and A. Furukawa and K. Sugase},
howpublished = {bioRxiv},
year = {2026},
month = oct,
doi = {10.64898/2026.10.25.761737},
url = {https://www.biorxiv.org/content/10.64898/2026.10.25.761737v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - Oxidized EGCG redirects α-synuclein aggregation through shear-selected interactions
AU - C. M. Yuen
AU - R. Yamaguchi
AU - K. Uchida
AU - Y. Shimada
AU - Y. Shuto
AU - S. Sakamoto
AU - D. Morimoto
AU - H. Ono
AU - M. So
AU - A. Furukawa
AU - K. Sugase
PY - 2026
DA - 2026/10/25
PB - bioRxiv
DO - 10.64898/2026.10.25.761737
UR - https://www.biorxiv.org/content/10.64898/2026.10.25.761737v1
AB - -Synuclein (Syn) aggregation is central to Parkinson's disease pathology, and the green-tea polyphenol epigallocatechin gallate (EGCG) has been studied as an inhibit fibril formation. However, EGCG autoxidation and analyses under static, non-fibrillating conditions have obscured whether activity arises from EGCG itself or oxidized species and which interactions persist during Syn assembly. Here we combine HPLC, LC-MS, TEM and solution NMR to compare unoxidized and oxidized EGCG (oxEGCG), while Rheo-NMR monitors Syn during shear-promoted assembly. Unoxidized EGCG showed no detectable binding under static, reducing conditions, whereas oxEGCG bound Syn, inhibited fibrillation and remodeled fibrils. Under shear flow, many oxEGCG-dependent perturbations partially reverted toward free Syn, whereas interactions near the NAC-C-terminal boundary were preferentially retained, coinciding with formation of oligomers and short, thick fibrils. These findings identify oxidation state and flow as determinants of EGCG action on Syn and show that Rheo-NMR distinguishes interactions that persist during shear-promoted assembly.
ER -