D-TLKIVWI peptide

• Handling and Storage of Synthetic Peptides
• Material Safety Data Sheets (MSDS)

Batch to batch variation of the purity

The D-TLKIVWI peptide is a short D-enantiomeric peptide that exhibits the ability to disassemble tau fibrils, specifically those associated with Alzheimer's disease (AD-tau). Structural studies reveal that D-TLKIVWI forms amyloid-like fibrils with a right-handed helical twist, characterized by a steric zipper motif composed of antiparallel β-sheets. When interacting with AD-tau, the peptide assembles into left-twisted fibrils templated by the tau fibrils, creating a strained complex. The release of this strain, as the peptide transitions back to its native right-handed conformation, generates torque sufficient to disrupt local hydrogen bonds in tau fibrils, leading to their fragmentation.

Cryo-electron microscopy (cryo-EM) and atomic force microscopy (AFM) analyses demonstrate that D-TLKIVWI fibrils adopt a right-handed twist in isolation but are constrained to a left-handed conformation when bound to AD-tau. High-speed AFM (HS-AFM) observations indicate that fragmentation occurs along periodic grooves in the fibrils, producing segments approximately 25 nm in length. The disassembly mechanism is driven by strain relief, without requiring external energy input, and results in non-seeding-competent fragments. This strain-relief mechanism provides insights into the structural basis of amyloid fibril disassembly by short peptides.

• Hou K, Ge P, Sawaya MR, Lutter L, Dolinsky JL, Yang Y, Jiang YX, Boyer DR, Cheng X, Pi J, Zhang J, Lu J, Abskharon R, Yang S, Yu Z, Feigon J, Eisenberg DS. How short peptides disassemble tau fibrils in Alzheimer's disease. Nature. 2025 Jul 9. doi: 10.1038/s41586-025-09244-z. Epub ahead of print. PMID: 40634605.

Trifluoroacetic acid (TFA) is a common counterion from the purification process using High-Performance Liquid Chromatography (HPLC). The presence of TFA can affect the peptide's net weight, appearance, and solubility.

Impact on Net Weight: The TFA salt contributes to the total mass of the product. In most cases, the peptide content constitutes >80% of the total weight, with TFA accounting for the remainder.

Solubility: TFA salts generally enhance the solubility of peptides in aqueous solutions.

In Biological Assays: For most standard in vitro assays, the residual TFA levels do not cause interference. However, for highly sensitive cellular or biochemical studies, please be aware of its presence.