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sC18 - Cys-functionalized


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CPP-P22 0,25 mg 121,80 Add to Basket/Quote Add to Notepad

For in vitro use only!

Shipping: shipped on blue ice

Storage Conditions: store at -20 °C
protect from light

Shelf Life: 12 months after date of delivery

Molecular Weight: 2713 Da confirmed by ESI-MS, peptide provides 9 positive charges in side chains for complex formation. Up to 10 trifluoroacetate residues may be present resulting in an apparent MW of 3.3 kDa.

Purity: > 99 % (HPLC)

Form: powder

Solubility: water

sC18 is a C-terminal fragment (aa 106-121) of the cationic amphipathic peptide CAP18. It facilitates internalization of cargo into living cells with high transduction rates and efficiencies. It shows no cytotoxic effects on a number of cell lines (including HeLa, MCF-7, HEK293, HT-29, FaDu, BJAB) up to a concentration of 100 μM. The transport of cargo requires in most cases formation of a covalent conjugate or fusion, however in some cases sC18 is able to form non-covalent complexes with the cargo as well. Addition of a 10 to 20 fold excess of free sC18 may increase rate and efficiency of cargo internalization.1-5

Cys-functionalized sC18 allows covalent coupling of thiol reactive compounds e.g.

  • maleimide-functionalized label (without addition of glutathione and Tris-(2-carboxy ethyl)phosphine within the labeling reaction6). Improved coupling with maleimide derivatives are described7-8
  • bromomethyl-phenyl-functionalized label9-10

Cystein (Cys) - functionalized peptide.

Stock solution:
Dissolve 0.25 mg in 0.75 ml sterile and oxygen-free water according to the general manual. Use the solution immediately or aliquot and store at -20 °C. Avoid freeze / thaw cycles. 1 μl of stock solution contains 0.33 μg peptide according to 0.1 nmol.

Perform calculation, complex formation and cargo transduction according to detailed protocols given in the general manual.

Selected References:
[1]Hoyer et al. (2012) Dimerization of a cell-penetrating peptide leads to enhanced cellular uptake and drug delivery. Beilstein J. Org. Chem. 8:1788.
[2] Richter et al. (2012) (18)F-Labeled phosphopeptide-cell-penetrating peptide dimers with enhanced cell uptake properties in human cancer cells. Nucl. Med. Biol. 39:1202.
[3] Splith et al. (2012) Specific targeting of hypoxic tumor tissue with nitroimidazole-peptide conjugates. ChemMedChem 7:57.
[4] Splith et al. (2010) Protease-activatable organometal-Peptide bioconjugates with enhanced cytotoxicity on cancer cells. Bioconjug. Chem. 21:1288.
[5] Reissmann (2014) Cell penetration: scope and limitations by the application of cell-penetrating peptides. J. Pept. Sci. 20:760.
[6] Tansi et al. (2015) Internalization of near-infrared fluorescently labeled activatable cell-penetrating peptide and of proteins into human fibrosarcoma cell line HT-1080.J. Cell. Biochem. 116:1222.
[7]Ryan et al. (2011) Tunable reagents for multi-functional bioconjugation: reversible or permanent chemical modification of proteins and peptides by control of maleimide hydrolysis. Chem. Commun. 47:5452.
[8] Badescu et al. (2014) A new reagent for stable thiol-specific conjuagtion. Bioconjugate Chem. 25:460.
[9] Smeenk et al. (2012) Synthesis of water-soluble scaffolds for peptide cyclization, labeling and ligation. Organic Lett. 14(5):1194.
[10] Dewkar et al. (2012) Synthesis of novel peptide linkers: simultaneous cyclization and labeling. Organic Lett. 11(20):4708.