Amines with SAMSA

SAMSA Labeled Protein with Protected Sulfhydryl 

Dissolve the protein or other amine-containing macromolecule in 0.1M sodium phosphate, 0.15M NaCl, pH 7.5, at a concentration of 5mg/ml. 

Add 20 pi of the stock SAMSA solution to each ml of the protein solution, with mixing. 

Hydrazone Linkage with Terminal Thiol Group 

Remove excess reagent and reaction by-products by dialysis or gel filtration using 0.1M sodium phosphate, 0.15M NaCl, lOmM EDTA, pH 7.5. For chromatographic separation, use a desalting gel filtration support such as the Zeba desalting spin columns (Thermo Fisher) or the equivalent. The SAMSA-modified protein may be stored at -20°C until needed. 

Remove excess reagent and reaction by-products by dialysis or gel filtration 

Thiolated Protein Containing Free Sulfhydryl Group 

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Figure 1.69 SAMSA is an anhydride compound containing a protected thiol. Reaction with protein amine groups yields amide bond linkages. Deprotection of the acetylated thiol produces free sulfhydryl groups for conjugation.

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