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Fmoc-N-amido-dPEG®₃₆-acid (QBD-10903)



“Fmoc-N-amido-dPEG®36-acid, product number QBD-10903, is one of a broad line of products designed for use in peptide synthesis. The long (112 atoms), flexible, discrete PEG (dPEG®) spacer is functionalized with a propionic acid group on one end and Fmoc-protected amine on the other. The compound can be added to the N-terminus of a growing peptide chain or to a primary-amine-functionalized side chain of an amino acid such as lysine. The non-immunogenic dPEG®36 spacer increases the hydrodynamic volume and imparts water solubility to the conjugate molecule.

QBD-10903 permits our customers to insert a dPEG® spacer into a peptide chain using familiar Fmoc chemistry using solid phase or solution phase chemistry. However, due to the spacer’s length, it may work better in solution-phase syntheses. The dPEG® compound can be inserted at either end of the peptide chain or in the middle of two amino acid sequences to provide a flexible linker between distinct functional peptides. Additionally, the dPEG® spacer can be used to provide spacing in a synthetic construct where steric hindrance is a problem. The amphiphilic nature of dPEG® products means that the construct gains hydrodynamic volume and water solubility while remaining soluble in organic solvent. The Fmoc protecting group is removed easily with a solution of piperidine in N,N-dimethylformamide (DMF).”


Unit Size100mg, 1000mg
Molecular Weight1897.22; single compound
Chemical formulaC₉₀H₁₆₁NO₄₀
Purity> 98%
SpacersdPEG® Spacer is 112 atoms and 131.4 Å
Typical solubility properties (for additional information contact Customer Support)Methylene chloride, Acetontrile, DMAC, DMSO or water.
Storage and handling-20°C; Always let come to room temperature before opening; be careful to limit exposure to moisture and restore under an inert atmosphere; stock solutions can be prepared with dry solvent and kept for several days (freeze when not in use). dPEG® pegylation compounds are generally hygroscopic and should be treated as such. This will be less noticeable with liquids, but the solids will become tacky and difficult to manipulate, if care is not taken to minimize air exposure.


Greg T. Hermanson, Bioconjugate Techniques, 3rd Edition, Elsevier, Waltham, MA 02451, 2013, ISBN 978-0-12-382239-0; See Chapter 18, Discrete PEG Reagents, pp. 787-821, for a full overview of the dPEG® products.

Lipo-Oligomer Nanoformulations for Targeted Intracellular Protein Delivery. Peng Zhang, Benjamin Steinborn, Ulrich Lachelt, Stefan Zahler, and Ernst Wagner. Biomacromolecules. 2017, June 26, 2017. DOI: 10.1021/acs.biomac.7b00666.

Flexible antibodies with nonprotein hinges. Daniel J. Capon, Naoki Kaneko, Takayuki Yoshimori, Takashi Shimada, Florian M. Wurm, Peter K. Hwang, Xiaohe Tong, Staci A. Adams, Graham Simmons, Taka-Aki Sato and Koichi Tanaka. The Japan Academy, Series B. 2011, 87 (9) pp 603-616. November 11, 2011. DOI: 10.2183/pjab.87.603.

A Systematic Analysis of Peptide Linker Length and Liposomal Polyethylene Glycol Coating on Cellular Uptake of Peptide-Targeted Liposomes. Jared F. Stefanick, Jonathan D. Ashley, Tanyel Kiziltepe, and Basar Bilgicer. ACS Nano. 2013, 7 (4) pp 2935–2947. February 19, 2013. DOI: 10.1021/nn305663e.

Enhanced Cellular Uptake of Peptide-Targeted Nanoparticles through Increased Peptide Hydrophilicity and Optimized Ethylene Glycol Peptide-Linker Length. Jared F. Stefanick, Jonathan D. Ashley, and Basar Bilgicer. ACS Nano. 2013, 7 (9) pp 8115–8127. August 29, 2013. DOI: 10.1021/nn4033954.

PEG-Peptide Conjugates. Ian W Hamley. Biomacromolecules. 2014, 15 (5) pp 1543-1559. April 1, 2014. DOI: 10.1021/bm500246w.

Evaluation of Nonpeptidic Ligand Conjugates for SPECT Imaging of Hypoxic and Carbonic Anhydrase IX-Expressing Cancers. Peng-Cheng Lv, Karson S. Putt, and Philip S. Low. Bioconjugate Chemistry. 2016, 27, pp 1762-1769. June 30, 2016. DOI: 10.1021/acs.bioconjchem.6b00271.

Bioresponsive nanocarries for targeted intracellular delivery of proteins and peptides. Ruth Elisabeth and Johanna Roder. Dissertation zur Erlangung des Doktorgrades der Fakultat fur Chemie und Pharmazie der Ludwig-Maximilians-Universitat Munchen. 2016, pp 1-128.

Efficient capture of circulating tumor cells with low molecular weight folate receptor-specific ligands. Yingwen Hu, Danyang Chen, John V Napoleon, Madduri Srinivasarao, Sunil Singhal, Cagri A Savran, Philip S Low. Scientific Reports. 2022. May 20, 2022.

Applicable patents and legal notices are available at legal notices.

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