ONLINE SOLID-PHASE SYNTHESIS OF A PEPTIDE BI-DERIVATIZED WITH BIOTIN AND 4-AZIDO SALICYLIC-ACID

The peptide (TSP)(4) is an efficient substrate for GalNAc transferase. (1) To localize the active site of GalNAc transferase, Biotin-(TSP)(4) -Lys(ASA)-G was prepared by on-line solid phase synthesis using Fmoc s trategy. The new protecting group, 1-(4,4-dimethyl-2,6-dioxocyclohexy- 1-ylidene) (Dde) was used as a temporary protecting group for N-epsilo n-lysine. The bi-derivatized peptide was characterized by mass spectro metry and FTIR spectrometry. This strategy can be generalized to other bi-derivatized peptides synthesized for ligand-receptor studies.