Alpha-synuclein has been linked to amyloidogenesis in Parkinson's disease and other neurodegenerative disorders. We have previously shown that a peptide comprising residues 68-78 of alpha-synuclein is the minimum fragment that, like alpha-synuclein itself, forms amyloid fibrils and exhibits toxicity towards cells in culture. Hughes et al. [J. Biol. Chem. 275 (2000) 25109] showed that an N-methylated derivative of Abeta(25-35) inhibited the formation of fibrils by Abeta(25-35) and reduced its toxicity. We have now extended this concept to an amyloidogenic alpha-synuclein-based peptide. Alpha-synuclein(68-78), N-methylated at G1y73, was compared to non-methylated peptide. Whereas alpha-synuclein(68-78) formed fibrils and was toxic to cells, the N-methylated analogue had neither of these properties. Moreover, an equimolar mixture of the non-methylated and methylated peptides formed very few fibrils and toxicity was markedly reduced.
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http://dx.doi.org/10.1016/j.neulet.2003.12.077 | DOI Listing |
Molecules
January 2025
Dipartimento di Chimica, Università di Pavia, Via Taramelli 12, 27100 Pavia, Italy.
Spontaneous cleavage reactions normally occur in vivo on amino acid peptide backbones, leading to fragmentation products that can have different physiological roles and toxicity, particularly when the substrate of the hydrolytic processes are neuronal peptides and proteins highly related to neurodegeneration. We report a hydrolytic study performed with the HPLC-MS technique at different temperatures (4 °C and 37 °C) on peptide fragments of different neuronal proteins (amyloid-β, tau, and α-synuclein) in physiological conditions in the presence of Cu and Zn ions, two metal ions found at millimolar concentrations in amyloid plaques. The coordination of these metal ions with these peptides significantly protects their backbones toward hydrolytic degradation, preserving the entire sequences over two weeks in solution, while the free peptides in the same buffer are fully fragmented after the same or even shorter incubation period.
View Article and Find Full Text PDFBiomolecules
December 2024
Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.
The maintenance of healthy mitochondria is essential for neuronal survival and relies upon mitochondrial quality control pathways involved in mitochondrial biogenesis, mitochondrial dynamics, and mitochondrial autophagy (mitophagy). Mitochondrial dysfunction is critically implicated in Parkinson's disease (PD), a brain disorder characterized by the progressive loss of dopaminergic neurons in the substantia nigra. Consequently, impaired mitochondrial quality control may play a key role in PD pathology.
View Article and Find Full Text PDFBiochemistry
January 2025
Sunita Sanghi Centre of Aging and Neurodegenerative Diseases (SCAN), Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
Aggregation of α-synuclein (α-Syn) and Lewy body (LB) formation are the key pathological events implicated in Parkinson's disease (PD) that spread in a prion-like manner. However, biophysical and structural characteristics of toxic α-Syn species and molecular events that drive early events in the propagation of α-Syn amyloids in a prion-like manner remain elusive. We used a neuronal cell model to demonstrate the size-dependent native biological activities of α-Syn fibril seeds.
View Article and Find Full Text PDFMol Neurobiol
December 2024
State Key Laboratory of Analytical Chemistry for Life Science, Division of Anatomy and Histo-Embryology, Medical School, Nanjing University, Nanjing, 210093, Jiangsu, China.
Microcystin-LR (MC-LR) is a natural neurotoxin with strong toxicity, and studies have demonstrated that chronic MC-LR exposure generated Parkinson-like dyskinesia in mice. Parkinson's disease (PD) is a neurologic degenerative disease mostly occurring in elderly people, and the progressive loss of dopaminergic neurons and the formation of Lewy bodies are the hallmark pathological features. The main component of Lewy bodies is α-synuclein (α-syn) encoded by the SNCA gene, and the copy number mutation of SNCA gene can promote the overexpression of α-syn.
View Article and Find Full Text PDFAlzheimers Res Ther
December 2024
University of Pompeu Fabra (UPF), Barcelona, Spain.
Background: Cerebrospinal fluid (CSF) biomarkers of synaptic dysfunction, neuroinflammation, and glial response, complementing Alzheimer's disease (AD) core biomarkers, have improved the pathophysiological characterization of the disease. Here, we tested the hypothesis that the co-expression of multiple CSF biomarkers will help the identification of AD-like phenotypes when biomarker positivity thresholds are not met yet.
Methods: Two hundred and seventy cognitively unimpaired adults with family history (FH) of sporadic AD (mean age = 60.
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