用Wang树脂和2-氯TRT树脂同时合成多肽

用Wang树脂和2-氯TRT树脂同时合成多肽 

Peptides which differ in the C-termini can be simultaneously synthesized in one reaction vessel by employing resins that possess different cleavage properties. The resins used were the weak acid labile 2-chlorotrityl resins and the TFA labile Wang resins. The success of this approach was shown by the co-synthesis of ACTH (4-10) with ACTH (4-11) and Neuropeptide Y, a C-terminal amide peptide with its corresponding C-terminal free acid analog. 
*Hong A., Le T., and Phan T. Techniques in Protein Chemistry VI, 531-562 (1995). 
切割程序 
Starting Resin: Chlorotrityl resins 
Reagents for 1 g Peptide-Resin:
1 mL acetic acid (AcOH)
2 mL trifluoroethanol (TFE)
7 mL dichloromethane (DCM)

• Prepare above mixture.

• Add peptide-resin to the mixture and let it stir at room temperature for 1 h.

• Filter and wash resin with 10 mL TFE:DCM (2:8) (2x) to ensure that all of the product is recovered.

• Evaporate the solvent until there is less than 5 mL of liquid.

• Add ether to a test tube containing about 100 mL of the above solution. Check solubility of the fully protected peptide in ether. If the product precipitates, proceed to step 6. If no precipitate is observed, proceed to step 7.

• Add cold ether to the residual liquid in step 4 to precipitate the fully protected peptide. Filter through a fine sintered funnel to obtain the product.

• Some fully protected peptides are soluble in ether. In this case, add water to precipitate them out. Filter through a fine sintered funnel to obtain the product.

从Fmoc-Lys(Mtt)氨基酸上脱去Mtt的方法 
Reagent:
Fmoc-Lys(Mtt)-OH

• Swell resin in DCM.

• Wash resin with 3% TFA/DCM (2x) (since the resin is swollen in DCM, this step of washing the resin quickly with 3% TFA/DCM ensures that the actual concentration of TFA is 3%).

• Shake the resin in 3% TFA for 10 min.

• Repeat step 3.

• Wash resin with DCM (3x), DMF (3x), isopropanol (3x), and DCM (3x).

• Let the resin dry in air.