dPEG®₂₄-SATA (S-acetyl-dPEG®₂₄-NHS ester)

dPEG®24-SATA, also known as S-acetyl-dPEG®24-NHS ester, product number 10188, is a modification of the widely popular thiolation reagent N-succinimidyl-S-acetylthioacetate, commonly known as SATA. The acetyl-protected thiol is separated from the N-hydroxysuccinimidyl (NHS) ester by a long, single molecular weight, amphiphilic, discrete chain length polyethylene glycol (dPEG®) spacer.

The widely popular SATA reagent contains an acetyl-protected thiol coupled to an NHS ester through acetic acid. SATA is used to install a protected thiol on molecules at accessible amines on a peptide or protein, which is a process known as thiolation. Deprotection of the thiol 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 poorly 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 the molecule in aqueous media.

Traditional polyethylene glycol (PEG) products are dispersed polymers (Đ > 1). PEG polymers contain an intractable mixture of different chain lengths and molecular weights of PEG in a Poisson distribution.

OurdPEG®24-SATA inserts a single molecular weight dPEG®24 spacer between the protected thiol and the NHS ester. The amphiphilic dPEG® spacer imparts water solubility to the molecule, allowing dPEG®24-SATA to be dissolved and reacted in water. Furthermore, the dPEG®24 spacer adds hydrodynamic volume to the molecule to which it is conjugated. This consequently reduces aggregation and precipitation of proteins conjugated to dPEG®24-SATA. Hydroxylamine hydrochloride (CAS number 5470-11-1) removes the acetyl protecting group easily, exposing the sulfhydryl group for further reaction.

Bioconjugation frequently employs thiolation. The reactions to install thiol groups on molecules or to react molecules with sulfhydryl groups are simple, easy, and often chemoselective.

Any application that can be carried out with a traditional, non-PEGylated SATA reagent can be carried out with our SATA containing a dPEG® spacer. 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®24-SATA (S-acetyl-dPEG®24-NHS ester) or any of our other SATA reagents.

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:

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.
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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