Fmoc-N-Lys-(dPEG®₄-biotin)-OH-(acid)

Fmoc-N-Lys-(dPEG®4-biotin)-OH, product number QBD-10613, permits the incorporation of a short (16 atoms), biotinylated discrete PEG (dPEG®) into a peptide chain using standard Fmoc chemistry. The biotin-dPEG®4 moiety is conjugated to the side chain of Fmoc-N-protected lysine. By design, this product permits the incorporation of a water-soluble biotin label into a peptide chain. The biotin label allows users to take advantage of the very strong affinity binding between biotin and avidin or streptavidin to use for pretargeted drug delivery, affinity chromatography, and other novel applications.

Peptide synthesis frequently uses PEGylation to improve the water solubility of hydrophobic peptides and protect peptides from enzymatic degradation in serum. The dPEG® linker also increases the PEGylated peptide’s hydrodynamic volume, which in turn increases the peptide’s half-life in serum. Fmoc-N-Lys-(dPEG®4-biotin)-OH uses familiar Fmoc chemistry with either solid phase or solution phase peptide synthesis. Although most customers will want to put the biotinyl-Lysine residue on one end of a peptide chain, the biotin label can be incorporated into the peptide chain wherever it is convenient to do so.
Biotin is normally poorly soluble in water or aqueous buffers. However, when conjugated to a short, discrete PEG linker, though, it becomes highly water-soluble. Moreover, because the dPEG®4 spacer adds hydrophilicity to the peptide, there will be fewer concerns about insolubility, aggregation, and precipitation than there would be if using biocytin or LC-biotin.