Chemoenzymatic Synthesis of Glycopeptides to Explore the Role of Mucin 1 Glycosylation in Cell Adhesion

Post-translational modifications affect protein biology under physiological and pathological conditions. Efficient methods for the preparation of peptides and proteins carrying defined, homogeneous modifications are fundamental tools for investigating these functions. In the case of mucin 1 (MUC1), an altered glycosylation pattern is observed in carcinogenesis. To better understand the role of MUC1 glycosylation in the interactions and adhesion of cancer cells, we prepared a panel of homogeneously O-glycosylated MUC1 peptides by using a quantitative chemoenzymatic approach. Cell-adhesion experiments with MCF-7 cancer cells on surfaces carrying up to six differently glycosylated MUC1 peptides demonstrated that different glycans have a significant impact on adhesion. This finding suggests a distinct role for MUC1 glycosylation patterns in cancer cell migration and/or invasion. To decipher the molecular mechanism for the observed adhesion, we investigated the conformation of the glycosylated MUC1 peptides by NMR spectroscopy. These experiments revealed only minor differences in peptide structure, therefore clearly relating the adhesion behaviour to the type and number of glycans linked to MUC1.

Automated summary

In this study, a panel of homogeneous O-glycosylated MUC1 peptides were prepared using a quantitative chemoenzymatic approach to investigate the impact of MUC1 glycosylation on cancer cell interactions and adhesion. Cell-adhesion experiments showed that different glycans significantly influenced adhesion, suggesting a distinct role for MUC1 glycosylation patterns in cancer cell migration and invasion. NMR spectroscopy studies revealed minor differences in peptide structure, linking the observed adhesion behavior to the type and number of glycans linked to MUC1.