title: Affinity of monoclonal antibodies for Globo-series glycans.
abstract: Globo-series glycans are human cell-surface carbohydrates that include stem-cell marker SSEA-4 and cancer-cell antigen Globo H. These two hexasaccharides differ only in their terminal saccharide: N-acetylneuraminic acid in SSEA-4 and L-fucose in Globo H. Herein, we evaluated the affinity of the monoclonal antibodies α-SSEA-4 and α-GH for the glycans SSEA-4 and Globo H. Using fluorescence polarization, we find that the two monoclonal antibodies have affinity for their cognate glycan in the low nanomolar range, and have negligible affinity for the non-cognate glycan. Using surface plasmon resonance, we find that each cognate affinity is ∼20-fold greater if the glycan is immobilized on a surface rather than free in solution. We conclude that the terminal saccharide plays a dominant role in the ability of monoclonal antibodies to recognize these Globo-series glycans and that the extraordinary specificity of these antibodies supports their use for identifying and sorting stem-cells (α-SSEA-4) and as an agent in cancer immunotherapy (α-GH).
authors.affiliation: Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706-1544, USA.
authors.forename: Chelcie H
authors.initials: CH
authors.lastname: Eller
authors.affiliation: Organic Synthesis Core Facility, Molecular Pharmacology & Chemistry Program, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA.
authors.forename: Guangbin
authors.initials: G
authors.lastname: Yang
authors.affiliation: Organic Synthesis Core Facility, Molecular Pharmacology & Chemistry Program, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA.
authors.forename: Ouathek
authors.initials: O
authors.lastname: Ouerfelli
authors.affiliation: Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706-1544, USA; Department Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA. Electronic address: rtraines@wisc.edu.
authors.forename: Ronald T
authors.initials: RT
authors.lastname: Raines
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology*; D000918:Antibody Specificity; D015295:Antigens, Tumor-Associated, Carbohydrate / Q000737:chemistry / Q000276:immunology*; D001896:Boron Compounds / Q000737:chemistry; D005454:Fluorescence Polarization; D006801:Humans; D012996:Solutions; D055746:Stage-Specific Embryonic Antigens / Q000737:chemistry / Q000276:immunology*; D020349:Surface Plasmon Resonance
chemical_list: C095489:4,4-difluoro-4-bora-3a,4a-diaza-s-indacene; D000911:Antibodies, Monoclonal; D015295:Antigens, Tumor-Associated, Carbohydrate; D001896:Boron Compounds; C472765:Globo-H; D012996:Solutions; D055746:Stage-Specific Embryonic Antigens; C066584:stage-specific embryonic antigen-4
keywords: Cancer-cell antigen; Globo H; Globo-series glycan; Monoclonal antibody; SSEA-4; Stem-cell marker