Minimal requirements for the binding of selectin ligands to a C-type carbohydrate-recognition domain.
The C-type carbohydrate-recognition domains of E-selectin and rat serum mannose-binding protein have similar structures. Selectin/mannose-binding protein chimeras created by transfer of key sequences from E-selectin into mannose-binding protein have previously been shown to bind the selectin ligand sialyl-Lewis(X) through a Ca(2+)-dependent subsite, common to many C-type lectins, and an accessory site containing positively charged amino acid residues. Further characterization of these chimeras as well as analysis of novel constructs containing additional regions of E-selectin demonstrate that selectin-like interaction with sialyl-Lewis(X) can be faithfully reproduced even though structural evidence indicates that the mechanisms of binding to E-selectin and the chimeras are different. Selectin-like binding to the nonfucosylated sulfatide and sulfoglucuronyl glycolipids can also be reproduced with selectin/mannose-binding protein chimeras that contain the two subsites involved in sialyl-Lewis(X) binding. These results indicate that binding of structurally distinct anionic glycans to C-type carbohydrate-recognition domains can be mediated by the Ca(2+)-dependent subsite in combination with a positively charged region that forms an ionic strength-sensitive subsite.
Bouyain
S
S
Glycobiology Institute, Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK.
Rushton
S
S
Drickamer
K
K
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites / Q000235:genetics; D002118:Calcium / Q000378:metabolism; D050260:Carbohydrate Metabolism; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D019040:E-Selectin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006017:Glycolipids / Q000378:metabolism; D066298:In Vitro Techniques; D008024:Ligands; D037241:Mannose-Binding Lectins; D051379:Mice; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009844:Oligosaccharides / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D009994:Osmolar Concentration; D017434:Protein Structure, Tertiary; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D000080506:Sialyl Lewis X Antigen
D002352:Carrier Proteins; D019040:E-Selectin; D006017:Glycolipids; D008024:Ligands; D037241:Mannose-Binding Lectins; D009844:Oligosaccharides; D011993:Recombinant Fusion Proteins; D000080506:Sialyl Lewis X Antigen; D002118:Calcium