Phosphorylation plays a vital role in the regulation of cellular processes. Each phosphorylation pattern leads to different interactions and could result in distinct biological outcomes.

Single phosphorylated peptides are frequently used for research. However, multi-site phosphorylations play a more important role in protein-protein interaction, nuclear import and export, and many other functions.

The monophosphorylated peptides are much easier to synthesize than multiphosphorylated peptides using traditional methods. There are many reasons for the difficulties. First of all, the steric hindrance of the protected phosphorylated amino acids would decrease the coupling yield. In addition, the protecting group and cleavage conditions are very harsh for conventional methods.

LifeTein adapted the microwave-assisted heating technology for multiphosphorylated peptide synthesis. Our method increases the coupling efficiency with good yields. In our study, we utilized the optimized conditions for synthesizing peptides containing six phosphorylated amino acids.