It plays an important role in life processes, phosphorylating Tyrr, Ser, Thr, located on peptides. The phosphorylated amino acid is commonly used in the production of phosphoric acid peptide, currently used in single phenyl phosphorylated amino acids. HBTU/phosphorylated amino acids are commonly used to connect the phosphorylated amino acids HOBt/DIEA method, but the phosphoric acid peptide are choosing this approach defects, especially in the generated much longer peptide peptides or amino acid phosphate, connecting the efficiency is low, low purity of the final product. For this phosphopeptide, we considered a selective post-phosphorylation approach. The generation process is the selective removal of amino acid side-chain protective groups that need to be labeled after peptide synthesis. For Tyr, Thr can react directly using amino acids with unprotected side chains. -Ser (trt), quantitatively removed at 1%TFA /DCM environment.
Phosphorylation, with double benzene phosphite phosphoramide and four nitrogen are generated and phosphoramide tetrazolium active intermediates, connected to the hydroxy, then under the acid peroxide oxidation phosphoryl formation, complete reaction.
At present, the peptide phosphorylated modification method there are two main types:
(1) direct introduction of moderately guaranteed phosphorylated amino acids into the polypeptide sequence;
(2) after the resin generated on the peptide sequence, to Ser, Tyr, or Thr phosphorylation of side chain hydroxyl.
1) will moderate guarantee phosphorylated amino acids directly introduce peptide sequence:
That is, amino acids that need to be phosphorylated will be phosphorylated and appropriately protected in advance using (Thr,Ser or Tyr), and then the phosphorylation will be narrowed down to the selection point of the polypeptide index based on the normal SPPS generation process. This method is easy to operate, has become the main method of peptide enterprises phosphorylated modification.
2) after the resin generated on the peptide sequence, to Ser hydroxy phosphorylation, Tyr, or Thr side chains:
Phosphorylation decoration using the phosphorylation of a single contraction into the polypeptide method, due to the steric hindrance generated by large groups in the side chain decoration, it is difficult for the phosphorylation of amino acids to shrink with the peptide chain. In the future, the introduction of amino acids will be more difficult, especially in the decoration containing multiple phosphorylation sites, the generation will become extremely difficult, the final product composition is complex, difficult to separate, and the yield is extremely low.
Therefore, when multiple sites in the peptide chain are phosphorylated, one can choose to generate the peptide sequence on the resin and then phosphorylate it by the side chain hydroxyl group of Ser, Tyr, or Thr: its generation mainly involves the selective removal of the side chain protective group that requires the recognition of amino acids after peptide synthesis. For Tyr, Thr can directly use the amino acid side chains are not protected in response.
Side chain protection base 1% TFA/DCM environment can quantitatively removed. When this method is chosen, a phosphoramidite tetrazolium active intermediate can be generated using dibenzyl phosphoramidite and tetrazolium, linked to a hydroxyl group, and then oxidized to form a phosphoryl group in the peroxyacid environment to complete the reaction.
Post time: Sep-08-2023