H-Trp-Phe-Tyr-Ser (PO3H2) -Pro-Arg-pNA

H-Trp-Phe-Tyr-Ser (PO3H2) -Pro-Arg-pNA serves as a chromogenic substrate for Pin1, a conserved mitotic peptidyl-prolyl isomerase that recognizes phosphoserine-proline bonds in mitotic phosphoproteins [1] [2].

C([C@@H](C(N[C@@H](CC1=CC=CC=C1)C(N[C@@H](CC2=CC=C(O)C=C2)C(N[C@H](C(=O)N3[C@H](C(N[C@H](C(NC4=CC=C(N(=O)=O)C=C4)=O)CCCNC(=N)N)=O)CCC3)COP(=O)(O)O)=O)=O)=O)N)C=5C=6C(NC5)=CC=CC6