A substrate for DNA-dependent protein kinase (DNA-PK), phosphorylation. DNA-PK is essential for the repair of DNA double-strand breaks. This peptide corresponding to 11–24 amino acids of human p53 with threonine 18 and serine 20 changed to alanine is used as a substrate for the assay of DNA-PK activity
Pyroglutamyl (pGlu) peptides may spontaneously form when either Glutamine (Q) or Glutamic acid (E) is located at the sequence N-terminus. The conversion of Q or E to pGlu is a natural occurrence and in general it is believed that the hydrophobic γ-lactam ring of pGlu may play a role in peptide stability against gastrointestinal proteases. Pyroglutamyl peptides are therefore considered a normal subset of such peptides and are included as part of the peptide purity during HPLC analysis.