Traditional Homobifunctional Crosslinkers
Homobifunctional crosslinkers join two different molecules using the same reactive group. Traditional homobifunctional crosslinkers are hydrophobic. With hydrophobic crosslinkers, aggregation and precipitation of conjugated molecules can be a severe problem. Moreover, all homobifunctional crosslinkers tend to polymerize uncontrollably. Also, when conjugating large biomolecules such as proteins, homobifunctional crosslinkers react both intermolecularly and intramolecularly. Such mixed reactions create a wide variety of products that are difficult to characterize.
The dPEG® difference with Acid-dPEG®5-NHS ester
Quanta BioDesign designed Acid-dPEG®5-NHS ester, product number 10109, to overcome the problems that typically accompany the use of homobifunctional crosslinkers.
Firstly, the amphiphilic dPEG® backbone imparts water solubility to conjugates. Our dPEG® technology creates unique PEG-based products that are soluble in both organic and aqueous media. These products provide all the benefits of traditional PEG products without the attendant difficulties of dispersity. For a thorough explanation of our dPEG® products and technology, please visit our “What is dPEG®?” page. For answers to our most frequently asked questions, please click this link.
Secondly, while both ends of the molecule can react with free amines such as the ε-amine group of lysine, only one end of the dPEG® spacer is activated as the NHS ester. This construction permits only one end of the spacer to react at one time. Thus, users of Acid-dPEG®5-NHS ester react the NHS ester end of the dPEG® molecule with free amines on, for example, a small molecule, peptide, or amine-functionalized surface using appropriate conditions. Then the propionic acid moiety on the opposite end of the molecule is activated with NHS or another suitable acylating agent such as 2,3,5,6-tetrafluorophenol (TFP). (Caution: Users should take care that there are no free amines left on the conjugate molecule that can react with the now-activated end of the dPEG® spacer.) The now-activated conjugate molecule then couples with a different compound or surface containing free amines, forming a unique, intermolecularly conjugated product.
Purchase Acid-dPEG®5-NHS ester Now
If you need a homobifunctional crosslinker in your R&D project but dread facing the problems that come from using traditional crosslinkers, click on the “Add to Cart” button now. Start using something that gives you a superior alternative to conventional crosslinkers.