Chemoenzymatic Synthesis of a MUC1 Glycopeptide Carrying Non-Natural Sialyl TF-β O-Glycan
A MUC1 type of glycopeptide was synthesized by the 9-fluorenylmethoxycarbonyl (Fmoc) solid-phase peptide synthesis (SPPS) protocol using benzyl and benzylidene-protected β-<small>D</small>-Gal-(1→3)-β-<small>D</small>-GalNAc-Ser/Thr (TF-β: a stereoisomer of the Thomsen-Friedenreich antigen). The synthetic glycopeptide was released from the resin with reagent K, and the resulting benzylated glycopeptide was deprotected under conditions of low-acidity trifluoromethanesulfonic acid (TfOH). The glycopeptide carrying duplicate non-natural <I>O</I>-glycans was dominant in the products, but was accompanied by a considerable amount of the glycopeptide missing one of the <I>O</I>-glycans. In contrast, the native α-glycoside was relatively stable under the acidic debenzylation conditions as shown by a parallel experiment with the glycopeptide involving α-<small>D</small>-GalNAc-Ser/Thr linkage. Enzymatic glycosylation with CMP-NeuAc was successful with both natural and non-natural <I>O</I>-glycans of the synthetic glycopeptide.
- Bioscience, biotechnology, and biochemistry
Bioscience, biotechnology, and biochemistry 70(10), 2515-2522, 2006-10-23
Japan Society for Bioscience, Biotechnology, and Agrochemistry