Structural and Metabolic Studies of Glycosaminoglycans (Sulfatase, Hydrazine, Mucopolysaccharidosis)

A method for chemical cleavage of glycosaminoglycans (GAGs) at N-acetylhexosamine residues was developed. The reaction scheme involved N-deacetylation of the N-acetylhexosamine residues with hydrazine (N(,2)H(,4)) followed by nitrous acid (HONO) cleavage of the polymer at pH 4.0. Initial studies with heparin-derived model compounds indicated that ester and N-sulfate substituents were stable during N(,2)H(,4) treatment but that uronic acids were converted to hydrazides which were epimerized at C-5 during the hydrazinolysis reaction. Subsequently, it was found that uronic acid hydrazides could be oxidized to uronic acids by HONO or iodic acid (HIO(,3)) treatment. The chemical cleavage method was used to convert reference GAGs to disaccharides which were reduced with NaB('3)H(,4) and separated by paper chromatography and anion exchange HPLC. Mono- and disulfated disaccharides from keratan sulfate (KS), the chondroitin sulfates (CS), and dermatan sulfate (DS) were identified. The relative amounts of CS and DS disaccharides released following a 10 hr N(,2)H(,4) treatment were found to be comparable to the corresponding products released by treatment of these polymers with chondroitinase ABC or chondroitinase AC. A study of the rates of disaccharide release during the N(,2)H(,4)/HONO treatment of reference GAGs indicated that 4-sulfation of CS significantly decreased the overall N-deacetylation rate.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Biochemistry

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2014

Author dc:creator

• Shaklee, Patrick Neil

• Chemistry, Biochemistry

Identifier

(UMI)AAI8521877

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/70543