Binding of sialyl Lewis x to E-selectin as measured by fluorescence polarization
| Autor: | Christine Kirmaier, Gary S. Jacob, Christina N. Steininger, Susan C. Howard, Peter Richard Scudder, S. Zaheer Abbas, Joseph K. Welply |
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| Rok vydání: | 1995 |
| Předmět: |
Stereochemistry
Molecular Sequence Data Oligosaccharides Fluorescence Polarization In Vitro Techniques Biochemistry law.invention chemistry.chemical_compound law E-selectin Tetrasaccharide Humans Sialyl Lewis X Antigen Fluorescent Dyes biology Molecular Structure Cell adhesion molecule Fluorescence Recombinant Proteins Dissociation constant Sialyl-Lewis X chemistry Carbohydrate Sequence biology.protein Recombinant DNA E-Selectin Cell Adhesion Molecules Fluorescence anisotropy Protein Binding |
| Zdroj: | Biochemistry. 34(4) |
| ISSN: | 0006-2960 |
| Popis: | Fluorescence polarization has been used to directly measure the binding of the tetrasaccharide sialyl Lewisx (sLe(x)[Glc], or NeuAc alpha 2-3Gal beta 1-4[Fuc alpha 1-3]Glc) to a soluble form of E-selectin, a member of the class of adhesion molecules that plays an important role in immune-cell response to inflammation. The experiments utilized a fluorescent derivative of sLe(x)[Glc] with fluorescein attached directly to the glucose residue through a beta-glycosidic linkage. The resulting fluorescent sLe(x) was shown to inhibit binding of HL60 cells to immobilized E-selectin and exhibited fluorescence polarization enhancement in the presence of a monovalent form of a recombinant soluble E-selectin-Fc chimera. Thermodynamic dissociation constants of 107 +/- 26 and 120 +/- 31 microM were obtained for the fluorescent sLe(x)[Glc] and the free sLe(x)[Glc] sugars, respectively. These results demonstrate that E-selectin interacts weakly with the minimal carbohydrate recognition determinant sLe(x). Additional binding interactions through the action of the authentic coreceptor or via clustering of the ligand and E-selectin molecules on the respective neutrophil and endothelial cell surfaces may also play a role in the overall cellular binding strength. However, the basic interaction between carbohydrate and protein appears weak, consistent with other carbohydrate-protein interactions studied to date. |
| Databáze: | OpenAIRE |
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