N-Acetylthyroxine → Thyroxine

Beteiligte Stoffe

Reaktionsschritte

STI is dissolved in 50 ml of borate-saline buffer pH 8.5, to a concentration of 16 mg/ml (38 μmole). N-hydroxysuccinimide ester of N-acetyl thyroxine (378 μmole, 346 mg) is dissolved in 50 ml of DMF in a separate container. Aliquots (2 ml) of the active ester in DMF are added to the STI at 5 minute intervals until all the active ester has been added. The reaction mixture is stirred at room temperature for an additional 3.5 hours, then terminated by dialysis against 2 liters of aqueous triethylamine pH 11. Chromatography of the product on a Sephadex G-75 column (5×100 cm) equilibrated with aqueous triethylamine, pH 11 is then conducted to isolate thyroxine (T4) conjugated to soybean trypsin inhibitor from free T4. Fractions containing 1-2 molecules of thyroxine per molecule of protein are isolated as the preferred reagent. Higher substituted fractions were obtained, although operable, they were less preferable.

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