title: Preparation and use of microarrays containing synthetic heparin oligosaccharides for the rapid analysis of heparin-protein interactions.
abstract: Heparin is a highly sulfated, linear polymer that participates in a plethora of biological processes by interaction with many proteins. The chemical complexity and heterogeneity of this polysaccharide can explain the fact that, despite its widespread medical use as an anticoagulant drug, the structure-function relationship of defined heparin sequences is still poorly understood. Here, we present the chemical synthesis of a library containing heparin oligosaccharides ranging from di- to hexamers of different sequences and sulfation patterns. An amine-terminated linker was placed at the reducing end of the synthetic structures to allow for immobilization onto N-hydroxysuccinimide activated glass slides and creation of heparin microarrays. Key features of this modular synthesis, such as the influence of the amine linker on the glycosidation efficiency, the use of 2-azidoglucose as glycosylating agents for oligosaccharide assembly, and the compatibility of the protecting group strategy with the sulfation-deprotection steps, are discussed. Heparin microarrays containing this oligosaccharide library were constructed using a robotic printer and employed to characterize the carbohydrate binding affinities of three heparin-binding growth factors. FGF-1, FGF-2 and FGF-4 that are implicated in angiogenesis, cell growth and differentiation were studied. These heparin chips aided in the discovery of novel, sulfated sequences that bind FGF, and in the determination of the structural requirements needed for recognition by using picomoles of protein on a single slide. The results presented here highlight the potential of combining oligosaccharide synthesis and carbohydrate microarray technology to establish a structure-activity relationship in biological processes.
authors.affiliation: Laboratory for Organic Chemistry, Swiss Federal Institute of Technology ETH Zürich, Wolfgang-Pauli-Strasse 10, HCI F315, 8093 Zürich, Switzerland.
authors.forename: Christian
authors.initials: C
authors.lastname: Noti
authors.forename: Jose L
authors.initials: JL
authors.lastname: de Paz
authors.forename: Laura
authors.initials: L
authors.lastname: Polito
authors.forename: Peter H
authors.initials: PH
authors.lastname: Seeberger
mesh_terms: D043924:Angiogenesis Modulating Agents / Q000737:chemistry / Q000378:metabolism; D000925:Anticoagulants / Q000494:pharmacology; D001665:Binding Sites; D002240:Carbohydrate Sequence; D016220:Fibroblast Growth Factor 1 / Q000378:metabolism; D016222:Fibroblast Growth Factor 2 / Q000378:metabolism; D051519:Fibroblast Growth Factor 4 / Q000378:metabolism; D006031:Glycosylation; D006493:Heparin / Q000138:chemical synthesis*; D006497:Heparan Sulfate / Q000737:chemistry; D046228:Microarray Analysis; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000138:chemical synthesis*; D011506:Proteins / Q000737:chemistry*; D013329:Structure-Activity Relationship; D013388:Succinimides / Q000737:chemistry
chemical_list: D043924:Angiogenesis Modulating Agents; D000925:Anticoagulants; D016220:Fibroblast Growth Factor 1; D016222:Fibroblast Growth Factor 2; D051519:Fibroblast Growth Factor 4; D006493:Heparin; D006497:Heparan Sulfate; D009844:Oligosaccharides; D011506:Proteins; D013388:Succinimides; C001426:N-hydroxysuccinimide