Amino-dPEG®8–t-boc-hydrazide, product number 10957, is a monodisperse PEGylation reagent designed to crosslink carboxylates with aldehydes or ketones. The amphiphilic, single molecular weight, discrete-length PEG (dPEG®) chain is 30 atoms long (35.9 Å). The ends of the dPEG® spacer terminate with a free amine and a boc-protected hydrazide group. After the amino group reacts with a carboxylate or active ester (NHS or TFP), the tert-butyl protecting group deprotects with acid. The exposed hydrazide moiety then reacts with aldehydes or ketones, forming a hydrazone bond.
Why use dPEG® products?
Many conventional crosslinkers are hydrophobic. Hydrophobic crosslinkers cause well-known problems with biomolecules in aqueous media. These problems include aggregation, precipitation, and non-specific interactions. Consequently, among other issues, hydrophobic crosslinkers cause signal attenuation, signal loss, and false signaling (positive or negative).
One solution to the problem of hydrophobic crosslinkers is to insert a polyethylene glycol (PEG) chain between the crosslinker functional groups. PEG is amphiphilic (meaning that it dissolves in both water and organic solvents). Consequently, PEG increases water solubility and adds hydrodynamic volume to conjugates made with it. However, traditional PEGylation reagents are non-uniform (disperse) polymers. PEG dispersity creates analytical complexity for any conjugate made with conventional PEGylation reagents.
Quanta BioDesign’s dPEG® products are different. Because they are synthesized from high purity starting materials, our dPEG® products are monodispersed PEGylation reagents. Each dPEG® product contains a discrete chain length of PEG with a single molecular weight rather than a mixture of different chain lengths and molecular weights of PEG. The dPEG® difference includes a simplified analysis of conjugates, which saves our customers time and money.
Amino-dPEG®8–t-boc-hydrazide crosslinks carboxylic acids with aldehydes or ketones. The amine end reacts first followed by deprotection and reaction of the hydrazide group.
Amines react with carboxylic acids and their active esters to form amide bonds. A carbodiimide such as EDC permits direct coupling of the amine to the carboxylic acid. Active esters of carboxylic acids also react with amines. The two most common active esters are N-hydroxysuccinimide (NHS) and 2,3,5,6-tetrafluorophenol (TFP). TFP esters are more reactive and hydrolytically stable than NHS esters. Therefore, TFP esters are preferred for many reactions with amines.
The hydrazide group must be deprotected after reacting the amine end of the crosslinker. Deprotection with trifluoroacetic acid (TFA) or formic acid is a common technique. Once the hydrazide is exposed, it is free to react with an aldehyde or ketone to form a hydrazone bond (a stable form of Schiff base). To learn more about hydrazone bonds please visit our page “Oxime and Hydrazone Bioconjugation Reactions.”
One possible use for Amino-dPEG®8–t-boc hydrazide is crosslinking peptides or small molecules with the carbohydrate coats of glycoproteins. The carbohydrates on glycoproteins contain reactive aldehydes or ketones in small amounts. Moreover, sodium periodate induces the formation of reactive formyl groups within these carbohydrate coats. Many other possible uses exist, including surface modification and supramolecular construction.
Are Larger Quantities of Amino-dPEG®8–t-boc-hydrazide 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.
Buy It Now!
Hydrophobic crosslinkers create severe problems with biomolecules. Traditional, disperse PEGylation reagents add complexity and time to the analysis of conjugates made with them. Quanta BioDesign’s dPEG® reagents provide all of the benefits of traditional PEGylation reagents without the analytical complexity that comes from using disperse polymers. A simplified analysis saves time and money.
Why buy inferior hydrophobic or disperse polymer products? Buy Amino-dPEG®8–t-boc-hydrazide and discover the dPEG® difference.