dPEG®₈-SATA acid (S-acetyl-dPEG®₈-acid)



dPEG®8-SATA acid, also known as S-acetyl-dPEG®8-acid, product number 10182, contains an acetyl-protected thiol on one end of a discrete polyethylene glycol (dPEG®) spacer that terminates with a carboxylic acid. Designed for the thiolation of amine-containing surfaces, dPEG®8-SATA acid does not contain an active ester but can be directly coupled to amines or can be activated with a reactive ester such as N-hydroxysuccinimide (NHS), 2,3,5,6-tetrafluorophenol (TFP), or 2,3,4,5,6-pentafluorophenol (PFP), among others, prior to conjugation.

Bioconjugation frequently employs thiolation because the reactions to install thiol groups on molecules or to react with molecules containing sulfhydryl groups are simple, easy, and often chemoselective. The widely popular SATA reagent contains an acetyl-protected thiol coupled to an NHS ester through acetic acid. SATA is used to thiolate molecules at accessible amines on a peptide or protein. Removal of the acetyl protecting group from the sulfhydryl permits crosslinking between the SATA-modified molecule and a target molecule of interest that contains a thiol-reactive group, such as maleimide. Unfortunately, SATA is not highly soluble in water. Consequently, it must be dissolved in a dry organic solvent such as N,N’-dimethylformamide (DMF) or N,N’-dimethylacetamide (DMAC) before reacting it in water or aqueous buffer. For more information, please see Thiolation Reagents and Reactions. {link}

Quanta BioDesign’s dPEG®8-SATA acid inserts a single molecular weight octaethylene glycol (dPEG®8) spacer between the protected thiol and the carboxylic acid. Because dPEG®8-SATA acid is not functionalized with an active ester (NHS, TFP, PFP, etc.), it can be directly coupled to amines using 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) and, for example, hydroxybenzotriazole (HOBt). This may be preferable to using an active ester under some circumstances. The dPEG® spacer makes the molecule water soluble, allowing dPEG®8-SATA acid to be dissolved and reacted in water. Moreover, the dPEG®8 spacer adds hydrodynamic volume to the molecule to which it is conjugated. Consequently, proteins conjugated to dPEG®8-SATA are less susceptible to aggregation and precipitation. Hydroxylamine hydrochloride (CAS number 5470-11-1) permits easy removal of the acetyl protecting group, exposing the sulfhydryl moiety for further reaction.

Any application that can be carried out with a traditional, non-PEGylated SATA reagent can be carried out with dPEG®8-SATA acid. Greg Hermanson, in his reference work titled Bioconjugate Techniques, 3rd edition (see references 1 and 2, below), has protocols for the thiolation of enzymes, antibodies, avidin, streptavidin, phycobiliproteins, and amine-containing DNA using SATA. All of these protocols can be conducted successfully using dPEG®8-SATA acid (S-acetyl-dPEG®8-acid) or any of our other SATA reagents.

Traditional polyethylene glycol (PEG) products are dispersed polymers (Đ > 1). This means that PEG polymers contain an intractable mixture of different chain lengths and molecular weights of PEG in a Poisson distribution. Quanta BioDesign manufactures PEG products that are not dispersed (Đ = 1). The PEG contained in every PEG product made by Quanta BioDesign has a single molecular weight with a discrete chain length (hence the tradename dPEG®). For more information about dPEG® technology, please click here. {link}

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.

Application References:

  1. Hermanson, G. T. Chapter 2, Functional Targets for Bioconjugation. Bioconjugate Techniques, 3rd edition. Academic Press: New York, 2013, 127-228, particularly pages 165-170, discussing thiolation and SATA. Want to learn more about Greg’s book? Click here now for a review of Greg’s book and a link to purchase it.
  2. Hermanson, G. T. Chapter 18, PEGylation and Synthetic Polymer Modification. Bioconjugate Techniques, 3rd edition. Academic Press: New York, 2013, 787-838.

Additional information

Weight .5 oz
Dimensions .75 × .75 × 2 in