title: Modulation of glycan detection on specific glycoproteins by lectin multimerization.
abstract: Improved methods for studying glycans could spur significant advances in the understanding and application of glycobiology. The use of affinity reagents such as lectins and glycan-binding antibodies is a valuable complement to methods involving mass spectrometry and chromatography. Many lectins, however, are not useful as analytic tools due to low affinity in vitro. As an approach to increasing lectin avidity to targeted glycans, we tested the use of lectin multimerization. Several biotinylated lectins were linked together through streptavidin interactions. The binding of certain lectins for purified glycoproteins and glycoproteins captured directly out of biological solutions was increased using multimerization, resulting in the detection of lower concentrations of glycoprotein than possible using monomeric detection. The analysis of glycoproteins in plasma samples showed that the level of binding enhancement through multimerization was not equivalent across patient samples. Wheat germ agglutinin (WGA) reactive glycans on fibronectin and thrombospondin-5 were preferentially bound by multimers in pancreatic cancer patient samples relative to control samples, suggesting a cancer-associated change in glycan density that could be detected only through lectin multimerization. This strategy could lead to the more sensitive and informative detection of glycans in biological samples and a broader spectrum of lectins that are useful as analytical reagents.
authors.affiliation: Van Andel Research Institute, Grand Rapids, Michigan 49503, United States.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Cao
authors.forename: Katie
authors.initials: K
authors.lastname: Partyka
authors.forename: Mitchell
authors.initials: M
authors.lastname: McDonald
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Brouhard
authors.forename: Marina
authors.initials: M
authors.lastname: Hincapie
authors.forename: Randall E
authors.initials: RE
authors.lastname: Brand
authors.forename: William S
authors.initials: WS
authors.lastname: Hancock
authors.forename: Brian B
authors.initials: BB
authors.lastname: Haab
mesh_terms: D006023:Glycoproteins / Q000378:metabolism*; D006801:Humans; D037102:Lectins / Q000378:metabolism*; D010190:Pancreatic Neoplasms / Q000378:metabolism; D011485:Protein Binding / Q000502:physiology; D055503:Protein Multimerization / Q000502:physiology*; D014909:Wheat Germ Agglutinins / Q000378:metabolism
chemical_list: D006023:Glycoproteins; D037102:Lectins; D014909:Wheat Germ Agglutinins