Remove Cys side chain tBu Protecting Group Methods

Cys(tBu)Usually in TFA and I2 are relatively stable, so they are often used to combine to produce peptides with the third pair of disulfide bonds and above without disturbing the previous disulfide bond pairings.
Remove tBu The methods usually include mercury acetate and trichloromethylsilane /Diphenyl sulfoxide method.
The following is an introduction to the steps of the mercury acetate method:

1. Will bring tBu of peptides dissolved in ice TFA middle (5-10mg/ml)
2. Add 10 times the equivalent of mercury acetate and stir for 3 hours.
3. Rotate under reduced pressure to evaporate excess TFA, Dissolve in 10% acetic acid aqueous solution
4. Add 20 times the equivalent of mercaptoethanol and let it sit for 5 hours
5. Centrifuge to remove precipitate and then desalt or HPLC purification.