Date of Award

Summer 8-18-2023

Level of Access Assigned by Author

Open-Access Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Chemistry

Advisor

Matthew Brichacek

Second Committee Member

William Gramlich

Third Committee Member

Michael Kienzler

Additional Committee Members

Alice Bruce

Barbara Cole

Abstract

N-(2-thioethyl)-2-aminobenzamide (TEAB), a novel glycan auxiliary, was synthesized and its utility was evaluated. The auxiliary was conjugated to glycans by reductive amination with the water-stable reagent 2-picoline borane complex. Glycan products, which ranged from 1 to 7 linked hexoses, were all isolated in yields ranging from 60% to 90% after purification by reverse-phase chromatography. The novel conjugate introduces a convenient, shelf-stable thiol directly onto the desired free glycans with purification advantages and direct modification with efficient reactions through alkenes, halides, epoxides, disulfides, and carboxylates in yields of 49% to 93%. Subsequently, a thiol-selective modification of the BSA protein was used to generate a neoglycoprotein with a bifunctional PEG–maleimide linker. To further illustrate the utility of a thiol motif, 2-thiopyridine activation of a thiol-containing support facilitated the covalent chromatographic purification of labeled glycans in yields up to 63%. Additionally, initial proof of concept of implementation in a light printed microarray was explored and validated through FITC-labeled concanavalin A binding. The thiol-functionalized glycans produced greatly expand the diversity of bioconjugation tools that can be developed with glycans and enable a variety of biological investigations. Finally, some non-reductive amination techniques were preliminarily investigated which achieved labeling of a xylose species in non-anomeric positions in poor yields (

Download

Files over 10MB may be slow to open. For best results, right-click and select "save as..."

Included in

Chemistry Commons

Share