Abstract: The present invention provides a method of sugar-guided modifying a glycosylated polypeptide. First, a boronic acid group of a probe molecule and a sugar group of the glycosylated polypeptide form a first covalent bond. Next, an alkyne group of a modifying group and an azide group of the probe molecule form a second covalent bond by adding a promoter. As a result, the modifying group can be close to the glycosylated polypeptide. Then, the modifying group can bind to a nucleophilic residue that is near the sugar group, through a nucleophilic addition reaction. The method of the present invention can selectively modify a given site with the guidance of the sugar group.

Abstract: The present invention provides a method of sugar-guided modifying a glycosylated polypeptide. First, a boronic acid group of a probe molecule and a sugar group of the glycosylated polypeptide form a first covalent bond. Next, an alkyne group of a modifying group and an azide group of the probe molecule form a second covalent bond by adding a promoter. As a result, the modifying group can be close to the glycosylated polypeptide. Then, the modifying group can bind to a nucleophilic residue that is near the sugar group, through a nucleophilic addition reaction. The method of the present invention can selectively modify a given site with the guidance of the sugar group.

Abstract: The present invention relates to a method of traceless labeling glycoproteins on a surface and an application thereof. A test glycoprotein can be immobilized on a surface using a BA-tosyl probe and the BA-tosyl probe is then released using a releasing agent, so as to expose a glycan residue of the test glycoprotein. The exposed glycan residue of the test glycoprotein can be detected without altering native glycan structures. Moreover, the present invention further provides a detection kit of traceless labeling glycoproteins on a surface in the study of glycoprotein-protein interactions, which is suitable for using the aforementioned method.

Abstract: The present invention relates to a method of traceless labeling glycoproteins on a surface and an application thereof. A test glycoprotein can be immobilized on a surface using a BA-tosyl probe and the BA-tosyl probe is then released using a releasing agent, so as to expose a glycan residue of the test glycoprotein. The exposed glycan residue of the test glycoprotein can be detected without altering native glycan structures. Moreover, the present invention further provides a detection kit of traceless labeling glycoproteins on a surface in the study of glycoprotein-protein interactions, which is suitable for using the aforementioned method.

Abstract: The present invention provides methods, compositions, and systems for mass spectrometric analysis of magnetic nanoparticles displaying ligands on their surface. For example, the present invention provides methods of screening a sample for the presence of at least one analyte using ligand conjugated magnetic nanoparticles, magnetic separation, and mass spectrometric analysis. The present invention also relates to MALDI matrix compositions comprising ligand conjugated magnetic nanoparticles.

Abstract: A method for immobilizing glycoprotein is disclosed. A surface is provided. Next, a boronic acid is contacted to the surface. The boronic acid is represented as Y—R—B—(OH)2 and includes a boronic acid group (B—(OH)2), a linker R, and a functional group Y, in which the boronic acid is bonded to the surface via the functional group Y. A glycoprotein is contacted to the boronic acid, wherein two spatially adjacent hydroxyl groups of a carbohydrate chain form a boronate ester with the boronic acid group of the boronic acid to immobilize the glycoprotein. The goal of site-specific and covalent protein immobilization without interfering the binding affinity of an antibody to antigen may be thus achieved with the reaction of boronic acid and the carbohydrate chain of Fc region.

Abstract: A method for immobilizing glycoprotein is disclosed. A surface is provided. Next, a boronic acid is contacted to the surface. The boronic acid is represented as Y—R—B—(OH)2 and includes a boronic acid group(B—(OH)2), a linker R, and a functional group Y, in which the boronic acid is bonded to the surface via the functional group Y. A glycoprotein is contacted to the boronic acid, wherein two spatially adjacent hydroxyl groups of a carbohydrate chain form a boronate ester with the boronic acid group of the boronic acid to immobilize the glycoprotein. The goal of site-specific and covalent protein immobilization without interfering the binding affinity of an antibody to antigen may be thus achieved with the reaction of boronic acid and the carbohydrate chain of Fc region.

Abstract: The present invention provides methods, compositions, and systems for mass spectrometric analysis of magnetic nanoparticles displaying ligands on their surface. For example, the present invention provides methods of screening a sample for the presence of at least one analyte using ligand conjugated magnetic nanoparticles, magnetic separation, and mass spectrometric analysis. The present invention also relates to MALDI matrix compositions comprising ligand conjugated magnetic nanoparticles.