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Tang J, Sun R, Wan J, Zou Y, Zhang Q. Molecular mechanisms involved in the destabilization of two types of R3-R4 tau fibrils associated with chronic traumatic encephalopathy by Fisetin. Phys Chem Chem Phys 2024; 26:3322-3334. [PMID: 38197437 DOI: 10.1039/d3cp05427f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2024]
Abstract
Chronic traumatic encephalopathy is a neurodegenerative tauopathy pathologically characterized by fibrillary tau aggregates in the depth of sulci. Clearing fibrous tau aggregates is considered a promising strategy in the treatment of CTE. Fisetin (FS), a natural polyphenolic small molecule, was confirmed to disassociate the tau filaments in vitro. However, the molecular mechanisms of FS in destabilizing the CTE-related R3-R4 tau fibrils remain largely unknown. In this study, we compared the atomic-level structural differences of the two types of CTE-related R3-R4 tau fibrils and explored the influence and molecular mechanisms of FS on the two types of fibrils by conducting multiple molecular dynamics (MD) simulations. The results reveal that the type 1 fibril displays higher structural stability than the type 2 fibril, with a lower root-mean-square-fluctuation value and higher β-sheet structure probability. FS can destabilize both types of fibrils by decreasing the β-sheet structure content, interrupting the mainchain H-bond network, and increasing the solvent accessible surface area and β7-β8 angle of the fibrils. H-bonding, π-π stacking and cation-π are the common interactions driving FS molecules binding on the two types of fibrils, while the hydrophobic interaction occurs only in the type 2 fibril. Due to the relatively short simulation time, our study captures the early molecular mechanisms. However, it does provide beneficial information for the design of drugs to prevent or treat CTE.
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Affiliation(s)
- Jiaxing Tang
- School of Physical Education, Shanghai University of Sport, 399 Changhai Road, Shanghai 200438, People's Republic of China.
| | - Ruiqing Sun
- School of Physical Education, Shanghai University of Sport, 399 Changhai Road, Shanghai 200438, People's Republic of China.
| | - Jiaqian Wan
- School of Physical Education, Shanghai University of Sport, 399 Changhai Road, Shanghai 200438, People's Republic of China.
| | - Yu Zou
- Department of Sport and Exercise Science, College of Education, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, Zhejiang, People's Republic of China.
| | - Qingwen Zhang
- School of Physical Education, Shanghai University of Sport, 399 Changhai Road, Shanghai 200438, People's Republic of China.
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Zou Y, Qi B, Tan J, Guan L, Zhang Q, Sun Y, Huang F. Deciphering the Inhibitory Mechanism of Naphthoquinone-Dopamine on the Aggregation of Tau Core Fragments PHF6* and PHF6. ACS Chem Neurosci 2023; 14:3265-3277. [PMID: 37585669 DOI: 10.1021/acschemneuro.3c00434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/18/2023] Open
Abstract
The formation of neurofibrillary tangles by abnormal aggregation of tau protein is considered to be an important pathological characteristic of tauopathies, including Alzheimer's disease and chronic traumatic encephalopathy. Two hexapeptides 275VQIINK280 and 306VQIVYK311 in the microtubule binding region, named PHF6* and PHF6, are known to be aggregation-prone and responsible for tau fibrillization. Previous experiments reported that naphthoquinone-dopamine (NQDA) could effectively inhibit the aggregation of PHF6* and PHF6 and disrupt the fibrillar aggregates into nontoxic species, displaying a dual effect on the amyloid aggregation. However, the underlying molecular mechanism remains mostly elusive. Herein, we performed all-atom molecular dynamics (MD) simulations for 114 μs in total to systematically investigate the impacts of NQDA on the oligomerization of PHF6* and PHF6. The conformational ensembles of PHF6* and PHF6 peptides generated by replica exchange MD simulations show that NQDA could effectively prevent the hydrogen bond formation, reduce the ability of peptides to self-assemble into long β-strand and large β-sheets, and induce peptides to form a loosely packed and coil-rich oligomer. The interaction analysis shows that the binding of NQDA to PHF6* is mainly through hydrophobic interactions with residue I277 and hydrogen bonding interactions with Q276; for the PHF6 peptides, NQDA displays a strong π-π stacking interaction with residue Y310, thus impeding the Y310-Y310 π-π stacking and I308-Y310 CH-π interactions. The DA group of NQDA displays a stronger cation-π interaction than the NQ group, while the NQ group exhibits a stronger π-π stacking interaction. MD simulations demonstrate that NQDA prevents the conformational conversion to β-sheet-rich aggregates and displays an inhibitory effect on the oligomerization dynamics of PHF6* and PHF6. Our results provide a complete picture of inhibitory mechanisms of NQDA on PHF6* and PHF6 oligomerization, which may pave the way for designing drug candidates for the treatment of tauopathies.
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Affiliation(s)
- Yu Zou
- Department of Sport and Exercise Science, College of Education, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, Zhejiang, P. R. China
| | - Bote Qi
- Department of Sport and Exercise Science, College of Education, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, Zhejiang, P. R. China
| | - Jingwang Tan
- Department of Sport and Exercise Science, College of Education, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, Zhejiang, P. R. China
| | - Lulu Guan
- Department of Sport and Exercise Science, College of Education, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, Zhejiang, P. R. China
| | - Qingwen Zhang
- College of Physical Education, Shanghai University of Sport, 399 Changhai Road, Shanghai 200438, P. R. China
| | - Yunxiang Sun
- Department of Physics, Ningbo University, 818 Fenghua Road, Ningbo 315211, Zhejiang, P. R. China
| | - Fengjuan Huang
- Ningbo Institute of Innovation for Combined Medicine and Engineering (NIIME), Ningbo Medical Center Lihuili Hospital, Ningbo 315211, Zhejiang, P. R. China
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Sharma S, Tomar VR, Deep S. Mechanism of the interaction of toxic SOD1 fibrils with two potent polyphenols: curcumin and quercetin. Phys Chem Chem Phys 2023; 25:23081-23091. [PMID: 37602388 DOI: 10.1039/d3cp02120c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/22/2023]
Abstract
Amyotrophic lateral sclerosis (ALS) is a debilitating neurodegenerative disease commonly caused due to the aggregation of superoxide dismutase 1 (SOD1) protein. Finding inhibitors of SOD1 aggregation is of prime concern, but understanding the mechanistic action of inhibitors is equally important. Recent experiments found that two polyphenols, curcumin, and quercetin, have the ability to inhibit SOD1 aggregation. Quercetin was experimentally proven to break pre-formed fibrils into shorter segments, while curcumin did not significantly affect the pre-formed species. Here, we delve deeper into understanding the mechanism of action of quercetin and curcumin on pre-formed octameric fibrils of SOD1 (28PVKVWGSIKGL38: chains A-H) with the help of molecular dynamics (MD) simulations of a fibril docked polyphenol complex. Our results suggest that quercetin shows π-π stacking interaction with one of the key residues for toxic amyloid formation, Trp 32 of chains D, E, and F, and breaks the peptide chains G, and H from the rest of the fibril. On the other hand, curcumin binds to the hydrophobic amino acids of almost all the chains B-H and stabilizes the fibril rather than destabilizing it. Binding free energy calculations using MM/PBSA showed that curcumin binds more strongly to the SOD1 fibril due to greater van der Waals interactions compared to quercetin. These findings provide insights for the development of potential ALS treatments.
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Affiliation(s)
- Shilpa Sharma
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India.
| | - Vijay Raj Tomar
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India.
| | - Shashank Deep
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India.
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