Thermo Scientific Pierce SATP is a long-chain (4.1 angstrom spacer arm) reagent for covalent modification of primary amines and addition of a protected yet exposable sulfhydryl group, enabling heterobifunctional crosslinking strategies.
SATP (N-succinimidyl-S-acetylthiopropionate) adds sulfhydryl groups to proteins and other amine-containing molecules in a protected form. The modified molecule can be stored indefinitely and treated with hydroxylamine to expose the labile sulfhydryl group when needed for conjugation reactions. SATP contains an N-hydroxysuccinimide (NHS) ester, which forms a stable, covalent amide bond with primary amines (i.e., lysine residues and the amino termini of proteins) and releases NHS as a by-product. De-protection (deacylation) to generate a free sulfhydryl is accomplished using hydroxylamine-HCl.
- Adds a protected sulfhydryl that can be deprotected by hydroxylamine
- Allows long-term storage of the sulfhydryl-modified molecule
- Offers more steric freedom than SATA for the unmasked sulfhydryl group
- Forms cleavable disulfide bonds with other sulfhydryl-containing molecules
- Reacts with primary amines (e.g., lysine residues proteins) to form stable amide bonds
- Preserves protein activity with its mild, non-denaturing reaction cdonditions
Structure and properties of SATP:
- Functional groups: NHS ester (amine-reactive) and sulfhydryl (protected)
- Spacer arm length: 4.1 angstroms
- Molecular weight: 245.25
- Chemical formula: C9H11NO5S
- CAS number: 84271-78-3
Sulfhydryl groups present on proteins, peptides and other compounds are important in protein chemistry/modification reactions. Frequently, thiols are unavailable or absent within the molecules of interest. Several reagents and techniques are available for introducing sulfhydryl groups or disulfides into proteins and peptides, including Traut's Reagent, variants of SPDP, and variants of SATA (e.g., SATP).
- Duncan, R.J.S., et al. (1983). A new reagent which may be used to introduce sulfhydryl groups into protein, and its use in the preparation of conjugates for immunoassay. Anal Biochem 132:68-73.
- Fuji, N., et al. (1985). Studies on peptides. CXXV. 3-3-p-methoxybenzylthiopropionyl)-thiazolidine-2-thione and its analogs as reagents for the introduction of the mercapto group into peptides and proteins. Chem Pharm Bull 33:362-7.
Overview of crosslinking and protein modification
SATA – alternative sulfhydryl-addition reagent
SAT(PEG)4 – alternative sulfhydryl-addition reagent with long, PEG spacer arm
Hydroxylamine – deprotects sulfhydryls after SATA modification
Traut's Reagent– small thiolation compound
SPDP – amine-to-sulfhydryl crosslinker