Dokument: Multi-scale affinity assays for the study of carbohydrate interactions. Effects of size, multivalency and scaffold flexibility
| Titel: | Multi-scale affinity assays for the study of carbohydrate interactions. Effects of size, multivalency and scaffold flexibility | |||||||
| URL für Lesezeichen: | https://docserv.uni-duesseldorf.de/servlets/DocumentServlet?id=48511 | |||||||
| URN (NBN): | urn:nbn:de:hbz:061-20190211-090732-0 | |||||||
| Kollektion: | Dissertationen | |||||||
| Sprache: | Englisch | |||||||
| Dokumententyp: | Wissenschaftliche Abschlussarbeiten » Dissertation | |||||||
| Medientyp: | Text | |||||||
| Autor: | Camaleño de la Calle, Alberto [Autor] | |||||||
| Dateien: |
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| Beitragende: | Jun. Prof. Dr. Schmidt, Stephan [Gutachter] Prof. Dr. Weinkauf, Rainer [Gutachter] | |||||||
| Dewey Dezimal-Klassifikation: | 500 Naturwissenschaften und Mathematik » 540 Chemie | |||||||
| Beschreibung: | Multivalency is a key principle in Nature to overcome the low affinity of biological ligands and receptors involved in crucial processes such as cellular adhesion, signaling and sensing. Researchers investigate how to utilize multivalency for the development of a new class of bioactive compounds being glycomacromolecules one of the most promising. In this regard, synthetic multivalent glycomimetics might become a suitable strategy. However, the precise control of the binding affinity is still very difficult hampering its development. Their affinity has been reported to be affected by various, and partially opposing contributions such as enthalpic gain due to additive binding of subunits at large multivalent scaffolds and entropic loss due to immobilization of mentioned scaffolds upon binding. Also, it is speculated that multivalent binding modes could have beneficial effects for binding at larger scales, e.g., using nanoparticles or colloids as scaffolds extending the valency and interacting area.
Using the well-known receptor/ligand pair concanavalin A (Con A) / α-D-mannose (Man), this work presents and validates various methods for the measurement of specific interactions at different size scales: linear glycomacromolecules (~1-7 nm Rh), protein scaffolds (~10 nm Ø), microgels (~30 μm Ø) and macroscopic glass (several cm2) while varying valency, density, length and flexibility of ligand tether to the scaffold. To this purpose, the scaffolds are functionalized with previously synthesized sequence-defined glycooligomers of presenting different amounts of mannose units at well-controlled spacing along the oligomer chain. At the single glycomacromolecule scale, the binding mode between the ligands on a molecule scaffold and a receptor functionalized surface were performed by means of single-molecule atomic force microscopy (SM-AFM). Regarding the analysis of protein scaffold scale, the specific binding and clustering rate of a sugar functionalized protein scaffolds are determined by fluorescence microscopy and turbidity measurements. Besides that, protein scaffolds are later used within cellular scale studies to test their inhibitory potential. For the cellular and macroscopic scales, the adhesion energy between ligand-receptor functionalized micrometersized soft colloidal probes (SCPs) and a surface are investigated by reflection interference contrast microscopy (RICM). Overall, the effects of size, valency, density and flexibility on multivalent ligand-receptor interactions were investigated. This thesis confirms that the affinity enhancement of multivalent scaffolds grows with the number of moieties and stiffness and as expected, the steric repulsion also increased with the size and flexibility of ligands. | |||||||
| Lizenz: |  Urheberrechtsschutz | |||||||
| Fachbereich / Einrichtung: | Mathematisch- Naturwissenschaftliche Fakultät » WE Chemie » Organische Chemie und Makromolekulare Chemie | |||||||
| Dokument erstellt am: | 11.02.2019 | |||||||
| Dateien geändert am: | 11.02.2019 | |||||||
| Promotionsantrag am: | 07.12.2018 | |||||||
| Datum der Promotion: | 31.01.2019 |
