Open AccessTF-containing MUC1 glycopeptides fail to entice Galectin-1 recognition of tumor-associated Thomsen-Freidenreich (TF) antigen (CD176) in solution
Author(s) -
Forrest G FitzGerald,
Maria C. Rodriguez Benavente,
Camelia Garcia,
Yaima Rivero,
YashoNandini Singh,
Hongjie Wang,
Gregg B. Fields,
Mare Čudić
Publication year - 2020
Publication title -
glycoconjugate journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.737
H-Index - 86
eISSN - 1573-4986
pISSN - 0282-0080
DOI - 10.1007/s10719-020-09951-x
Subject(s) - glycan , galectin , muc1 , isothermal titration calorimetry , antigen , chemistry , tumor antigen , biochemistry , microbiology and biotechnology , biology , mucin , glycoprotein , immunology , cytotoxic t cell , in vitro
Aberrant Mucin-1 (MUC1) glycosylation with the Thomsen-Friedenreich (TF) tumor-associated antigen (CD176) is a hallmark of epithelial carcinoma progression and poor patient prognosis. Recognition of TF by glycan-binding proteins, such as galectins, enables the pathological repercussions of this glycan presentation, yet the underlying binding specificities of different members of the galectin family is a matter of continual investigation. While Galectin-3 (Gal-3) recognition of TF has been well-documented at both the cellular and molecular level, Galectin-1 (Gal-1) recognition of TF has only truly been alluded to in cell-based platforms. Immunohistochemical analyses have purported Gal-1 binding to TF on MUC1 at the cell surface, however binding at the molecular level was inconclusive. We hypothesize that glycan scaffold (MUC1's tandem repeat peptide sequence) and/or multivalency play a role in the binding recognition of TF antigen by Gal-1. In this study we have developed a method for large-scale expression of Gal-1 and its histidine-tagged analog for use in binding studies by isothermal titration calorimetry (ITC) and development of an analytical method based on AlphaScreen technology to screen for Gal-1 inhibitors. Surprisingly, neither glycan scaffold or multivalent presentation of TF antigen on the scaffold was able to entice Gal-1 recognition to the level of affinity expected for functional significance. Future evaluations of the Gal-1/TF binding interaction in order to draw connections between immunohistochemical data and analytical measurements are warranted.