SPDP-dPEG®36-acid, product number 10866, is a crosslinking reagent from Quanta BioDesign designed to conjugate free amines and sulfhydryls. The single molecular weight (i.e., monodispersed) PEG crossbridge between the two functional groups is 115 atoms (137.8 Å) long. Because the PEG chain length is discrete, Quanta BioDesign sells this product under the dPEG® tradename. Using a suitable carbodiimide, such as EDC, the propionic acid group reacts with free primary amines to form amide bonds. The pyridyl disulfide (SPDP, also known as OPSS) functional group reacts with free thiols to form disulfide bonds. This product is useful for crosslinking peptides, proteins, and small molecules, and modifying surfaces with suitable reactive sites.
PEGylation with Quanta BioDesign’s dPEG® Products
Quanta BioDesign’s dPEG® PEGylation reagents are quite different from traditional PEGylation reagents. Our products are not dispersed polymers, nor are they purified from polymeric mixtures. Instead, we synthesize all of our products from high-purity starting materials and maintain discrete chain lengths and single molecular weights throughout the entire synthetic process. To learn more about our products and technology, please visit our informational pages linked below.
Among the most popular heterobifunctional crosslinking reagents used in bioconjugate chemistry are those compounds that conjugate molecules containing free amine groups with molecules that contain sulfhydryl groups. SPDP (N-succinimidyl 3-(2-pyridyldithio)-propionate), also called OPSS, is one of the most popular versions of this type of crosslinker. Unfortunately, the most popular varieties of SPDP (LC-SPDP and Sulfo-LC-SPDP) are hydrophobic molecules. When conjugated to biomolecules, care must be taken not to modify the target molecules too much, because this can precipitate the conjugate products.
SPDP-dPEG®36-Acid, product number 10866, is used like SPDP and its related hydrophobic products. However, precautions against overly modifying the target molecule are not necessary. The water-soluble dPEG® product prevents hydrophobicity-triggered precipitation of compounds to which it is conjugated. Greg Hermanson’s Bioconjugate Techniques, 3rd edition, describes SPDP and related products (Chapter 6) and describes Quanta BioDesign’s dPEG® versions of these products (Chapter 18). Each of the chapters describing these crosslinkers contains detailed protocols for using them. Quanta BioDesign highly recommends and sells this book. Click here for a review and to purchase Bioconjugate Techniques, 3rd edition.
Bulk Scale Production is Available
If you need bulk product in a larger package size than our standard sizes, please contact us for a quote. Our commercial capabilities permit us to manufacture this product at any scale that you need.
If you need to conjugate amine and sulfhydryl groups, stop using inferior hydrophobic SPDP products. Click on the “Add to Cart” button today and start using our superior, water-soluble SPDP-dPEG®36-Acid product. You, too, can experience “the dPEG® difference” that thousands of other satisfied customers have enjoyed.