[Met(O)35]-beta-Amyloid (1-42)

Product Name: [Met(O)35]-beta-Amyloid (1-42)

Sequence One Letter Code: DAEFRHDSGYEVHHQKLVFFAEDVGSNKGAIIGL-M(O)-VGGVVIA

Sequence Three Letter Code: H-Asp-Ala-Glu-Phe-Arg-His-Asp-Ser-Gly-Tyr-Glu-Val-His-His-Gln-Lys-Leu-Val-Phe-Phe-Ala-Glu-Asp-Val-Gly-Ser-Asn-Lys-Gly-Ala-Ile-Ile-Gly-Leu-Met(O)-Val-Gly-Gly-Val-Val-Ile-Ala-OH

Cas No: 1802086-68-5

Chemical Formula:C203H311N55O61S

Molecular Weight: 4530.4

Purity: 95%

Form: Lyophilized

Storage Conditions: - 20 °C

Research Area: Neurological Disease Research

Source / Species: human

Conjugation: Unconjugated

Code Nacres: NA.26

Application: [Met(O)35]-β-Amyloid (1–42) is a synthetic amyloid-β peptide variant in which methionine at position 35 is selectively oxidized to the sulfoxide form, providing a precise model for studying oxidative modifications in Alzheimer’s disease research. Oxidation of Met35 alters the peptide’s redox characteristics, hydrophobic interactions, and aggregation kinetics, thereby influencing oligomer formation, fibril assembly, and membrane association. This modification has been shown to modulate reactive oxygen species generation and amyloid-induced cytotoxicity, making it particularly valuable for investigating the relationship between oxidative stress and neuronal injury. By comparing oxidized and non-oxidized forms of Aβ(1–42), researchers can dissect the contribution of redox-dependent structural changes to mitochondrial dysfunction, synaptic impairment, and downstream neurodegenerative pathways. [Met(O)35]-β-Amyloid (1–42) serves as a well-defined experimental tool for mechanistic studies of amyloid aggregation, oxidative damage, and the molecular basis of amyloid-driven neurotoxicity in cellular and biochemical models of neurodegeneration.

Current Research: Oxidative stress is a prominent feature of Alzheimer’s disease (AD) pathology and is closely intertwined with amyloid-β (Aβ) aggregation and toxicity. Among the residues in Aβ(1–42), methionine at position 35 (Met35), located within the C-terminal hydrophobic region, is particularly susceptible to oxidation. [Met(O)35]-β-Amyloid (1–42) is a synthetic peptide variant in which Met35 is selectively oxidized to methionine sulfoxide, providing a chemically defined system to investigate how redox modifications alter amyloid structure, aggregation behavior, and neurotoxicity. This reagent enables precise comparison between oxidized and non-oxidized forms of Aβ(1–42), facilitating mechanistic dissection of oxidative contributions to AD-related neurodegeneration. Met35 resides within a region critical for β-sheet formation, intermolecular packing, and membrane interaction. Oxidation of the sulfur atom introduces increased polarity and alters side-chain hydrophobicity, thereby modifying local structural interactions. These physicochemical changes influence the peptide’s conformational landscape and aggregation kinetics. In vitro studies using thioflavin T fluorescence and circular dichroism spectroscopy have demonstrated that oxidation at Met35 can alter nucleation and elongation phases of fibrillogenesis. Compared with native Aβ(1–42), the oxidized variant may display modified oligomer distributions, altered fibril morphology, or differences in aggregation rate depending on experimental conditions. The redox-dependent structural shift also affects intermolecular interactions within oligomeric assemblies. Because the C-terminal region contributes to stabilization of β-sheet–rich fibrils, oxidation at Met35 can perturb hydrophobic stacking and hydrogen bonding networks. Structural analyses using electron microscopy and nuclear magnetic resonance have revealed that oxidized Aβ species may form assemblies with distinct morphology and stability profiles. These differences are valuable for understanding how oxidative modifications reshape the amyloid energy landscape. Importantly, Met35 oxidation has been linked to modulation of reactive oxygen species (ROS) generation. Aβ peptides can catalyze redox reactions in the presence of transition metals such as copper and iron, contributing to oxidative stress in neuronal tissue. Alteration of the Met35 side chain influences the peptide’s redox chemistry and may change its capacity to participate in ROS production. Studies comparing oxidized and non-oxidized peptides provide insight into how structural oxidation impacts oxidative damage pathways. The oxidized variant is particularly relevant for investigating amyloid-induced cytotoxicity. Aβ oligomers disrupt cellular membranes, impair calcium homeostasis, and induce mitochondrial dysfunction. Because membrane association depends in part on the hydrophobic C-terminal region, oxidation at Met35 can alter lipid interactions and membrane insertion properties. Liposome leakage assays and cell-based toxicity experiments demonstrate that redox state influences the extent of membrane perturbation and downstream apoptotic signaling. These findings help clarify how oxidative stress modifies amyloid-mediated neuronal injury. Mitochondrial dysfunction is a hallmark of AD and is closely associated with Aβ accumulation. Comparative studies using [Met(O)35]-Aβ(1–42) enable examination of how redox-dependent structural differences affect mitochondrial membrane potential, cytochrome c release, and oxidative phosphorylation efficiency. By isolating a single defined modification, researchers can attribute observed cellular effects specifically to Met35 oxidation rather than to heterogeneous oxidative damage. In addition, the peptide supports investigation of oxidative stress feedback loops. Neuronal oxidative stress can promote Aβ oxidation, while oxidized Aβ may further enhance ROS generation, amplifying cellular injury. Using a site-specifically oxidized peptide allows controlled modeling of this interplay and assessment of antioxidant interventions in biochemical and cellular systems. From a translational perspective, [Met(O)35]-β-Amyloid (1–42) provides a stringent model for evaluating therapeutic agents aimed at mitigating oxidative damage or stabilizing non-toxic conformations. By comparing aggregation inhibitors, metal chelators, or antioxidant compounds against both oxidized and non-oxidized peptides, researchers can assess redox-dependent efficacy. In summary, [Met(O)35]-β-Amyloid (1–42) is a precisely oxidized amyloid variant that models redox modifications relevant to Alzheimer’s disease. By altering hydrophobic interactions, aggregation kinetics, and oxidative properties, Met35 oxidation influences oligomer formation, membrane association, and cytotoxic signaling. This well-defined peptide remains an essential experimental tool for elucidating the molecular relationship between oxidative stress and amyloid-driven neurodegeneration.