Methods for enriching glycopeptides for global analysis of glycoproteins

1. A method for enriching a glycan-containing molecule, the glycan-containing molecule comprising a glycan component, the method comprising:

preparing a dendrimer-benzoboroxole (DB) complex comprising:

a benzoboroxole compound conjugated to a dendrimer; and

a bead;

contacting the glycan-containing molecule with the DB complex at pH 9-11 to form a glycan-DB complex;

wherein the glycan-containing molecule is reversibly bound to the DB complex; and

wherein the benzoboroxole compound is a compound of Formula II:

.

2. The method of claim 1 further comprising:

washing the glycan-DB complex to remove non-glycan containing molecules from the glycan-DB complex.

3. The method of claim 1 further comprising:

releasing the glycan-containing molecule from the DB complex to form an enriched glycan-containing molecule;

wherein the releasing step is performed with an acid.

4. A composition comprising a dendrimer-benzoboroxole (DB) complex at pH 9 to 11 comprising:

a benzoboroxole compound of Formula II conjugated to a dendrimer;

a glycan-containing molecule covalently bound to the benzoboroxole compound; and

a bead,

wherein Formula II is:

wherein

the DB complex is configured to contact and enrich the glycan-containing molecule from a complex biological sample,

wherein the glycan-containing molecule is covalently bound to the DB complex under basic pH,

wherein the bead is configured to enable enrichment of the DB complex with the covalently bound glycan-containing molecule from the complex biological sample,

wherein the covalently bound glycan-containing molecule is released from the DB complex by an acid, and

wherein the released glycan-containing molecule is analyzed.

5. The composition of claim 4 , wherein the bead is a magnetic bead.

6. The composition of claim 4 , wherein a glycan component of the glycan-containing molecule is covalently bound to the benzoboroxole compound.

7. The composition of claim 4 , wherein a plurality of benzoboroxole compounds are conjugated to a single dendrimer.

8. The composition of claim 7 , wherein a glycan component of the glycan-containing molecule is covalently bound to the plurality of benzoboroxole compounds.

9. A method for analyzing glycosylation sites on a glycan-containing molecule, the glycan-containing molecule comprising at least one glycan component, the method comprising:

contacting the glycan-containing molecule with a dendrimer benzoboroxole (DB) complex at pH 9-11 to form a glycan-DB complex;

washing the glycan-DB complex to remove non-glycan-containing molecules from the glycan-DB complex;

releasing the glycan-containing molecule from the DB complex to form an enriched glycan-containing molecule;

cleaving the at least one glycan component from the enriched glycan-containing molecule; and

analyzing the at least one glycan component,

wherein the benzoboroxole is of Formula II:

10. The method of claim 9 , wherein:

the releasing step is performed by an acid; and

the analyzing step is performed by mass spectrometry.