MAL-dPEG®₁₂-Tris(-dPEG®₁₁-amido-MAL)₃

MAL-dPEG®12-Tris(-dPEG®11-amido-MAL)3, product number 11433, is a branched, single molecular weight, thiol-reactive, discrete polyethylene glycol (dPEG®) product consisting of four (4) branched dPEG® arms built around a tris core. Each arm terminates with a thiol-reactive maleimidopropyl group. Furthermore, each arm is 46 atoms long (58.6 – 59.6 Å) from the tris core to the reactive site on the maleimide moiety.

Thiol-Maleimide Reactions
The thiol-maleimide reaction is one of the most popular tools in the bioconjugation toolbox for conjugating a sulfhydryl group to another molecule. The reaction is a click chemistry type of reaction. It is chemoselective at pH 6.5 – 7.5 and can proceed in water or aqueous buffer, making it highly useful for reactions with peptides, proteins, and other sulfhydryl-containing biomolecules.

Conventional PEGylation Reagents vs. dPEG® PEGylation Reagents
Traditional polyethylene glycol (PEG) is a disperse polymer (Đ > 1). In a typical polymer PEG, the stated molecular weight does not represent a single compound. Instead, the molecular weight for traditional PEG is an average drawn from a large number of different chain lengths of PEG, each chain having a different molecular weight. The mixture of different chain lengths presents significant analytical challenges.

Quanta BioDesign invented discrete PEG (dPEG®) technology. In sharp contrast to traditional PEG, our dPEG® products have no dispersity (Đ = 1). Each dPEG® product is a single molecular weight compound. There are no mixtures of sizes. Moreover, we do not purify a single molecular weight of PEG out of a complex polymeric mixture. Instead, we build up our products from ultrapure starting materials and maintain uniform product purity throughout the synthetic, workup, and purification steps leading to the final product.

Using MAL-dPEG®12-Tris(-dPEG®11-amido-MAL)3
The four arms of MAL-dPEG®12-Tris(-dPEG®11-amido-MAL)3 are built around a core of tris(hydroxymethyl)aminomethane ("tris"). Although one arm is differently structured than the other three arms (one dPEG®12 arm vs. three dPEG®11 arms), each arm is the same number of atoms and the same length when measured from the reactive site on the maleimide to the tris core from which each arm branches. This precise construction occurs solely because the dPEG® spacers have discrete chain lengths.

This product can be used to link multiple peptides or proteins together for drug delivery. It could also be used as a core unit for constructing dendrimers with precisely defined spacer lengths.

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.

MAL-dPEG®12-Tris(-dPEG®11-amido-MAL)3 is a unique crosslinking product from Quanta BioDesign. Its precise construction is possible only because we use single molecular weight dPEG® products. If you need a four-arm thiol-reactive crosslinker with uniform molecular weight and structure, then you need MAL-dPEG®12-Tris(-dPEG®11-amido-MAL)3.

Application References:

Hermanson, G. T. Chapter 2, Functional Targets for Bioconjugation. Bioconjugate Techniques, 3rd edition. Academic Press: New York, 2013, 127-228.
Hermanson, G. T. Chapter 3, The Reactions of Bioconjugation. Bioconjugate Techniques, 3rd edition. Academic Press: New York, 2013, 229-258, specifically page 241, discussing maleimide reactions.
Hermanson, G. T. Chapter 8, Dendrimers and Dendrons. Bioconjugate Techniques, 3rd edition. Academic Press: New York, 2013, 351-386.
Hermanson, G. T. Chapter 18, PEGylation and Synthetic Polymer Modification. Bioconjugate Techniques, 3rd edition. Academic Press: New York, 2013, 787-838.

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