biotin-Ahx-RPARPAR-OH

RPARPAR is an 8-amino acid peptide with the sequence Arg-Pro-Ala-Arg-Pro-Ala-Arg-Pro. It serves as a prototypic example of the C-end Rule (CendR) peptides, which are characterized by a C-terminal R/KXXR/K motif. This motif enables the peptide to bind to neuropilin-1 (NRP-1), a receptor involved in various cellular processes, including endocytosis and tissue penetration. The C-terminal R/KXXR/K motif is crucial for the peptide's interaction with NRP-1, facilitating its uptake into cells and tissues.

Upon binding to NRP-1, RPARPAR activates an endocytic pathway that enhances the permeability of blood vessels, allowing for deeper tissue penetration. This mechanism is particularly valuable in targeting tumor vasculature, as it enables the delivery of therapeutic agents directly into tumor tissues.

Functional & Experimental Applications

• Drug Delivery: RPARPAR has been utilized to enhance the delivery of various therapeutic agents, including nanoparticles and small molecules, into tumor tissues.
• Imaging: The peptide has been employed in imaging studies to trace and visualize tumor vasculature and tissue penetration.
• Vascular Targeting: Due to its ability to bind to NRP-1, RPARPAR is used to target and manipulate blood vessels in various pathological conditions.

RPARPAR exemplifies how targeting specific receptors like NRP-1 can facilitate the delivery of therapeutic agents into tissues, offering potential avenues for enhancing the efficacy of treatments.

biotin-Ahx-RPARPAR-OH is a 7-residue synthetic peptide with the sequence Arg-Pro-Ala-Arg-Pro-Ala-Arg. Biotin provides an affinity handle for streptavidin-based capture or detection; the Ahx spacer separates the peptide from an attached label or affinity handle. The sequence is enriched in basic residues (0 Lys and 3 Arg), giving the sequence a cationic character under many aqueous conditions. No specific receptor, enzyme, pathway, disease association, or biological activity is assigned to this peptide without product-specific experimental evidence.

• streptavidin-based capture or detection
• binding and pull-down assay development
• LC-MS/HPLC analytical method development
• sequence-specific assay controls

Sequence-derived chemical properties are provided to support reagent selection and experimental planning. They do not establish a biological function. Solubility, aggregation, adsorption, conjugation efficiency, and assay performance should be validated under the intended experimental conditions.