Journal
BIOCHIMICA ET BIOPHYSICA ACTA-GENERAL SUBJECTS
Volume 1760, Issue 5, Pages 768-782Publisher
ELSEVIER SCIENCE BV
DOI: 10.1016/j.bbagen.2005.12.021
Keywords
agglutinin; drug targeting; lectin; sialylation; tumor imaging
Categories
Ask authors/readers for more resources
We address the question whether the two natural types of branching in complex-type triantennary N-glycans differ in ligand properties. Toward this end, we prepared the set of pergalactosylated undecasaccharides and derivatives with alpha 2,3/6-sialylation by chemoenzymatic synthesis. Conjugation resulted in neoglycoproteins which were tested in assays with lectins/antibodies, cultured cells and animals. Solid-phase assays with galactoside-specific proteins (a plant toxin, galectins and an antibody fraction) disclosed that the branching mode did not significantly affect affinity. However, compared to previous studies under identical conditions increase in antennae number and presence of substitutions in biantennary N-glycans altered K(D)-values with differences between receptors. Neoglycoprotein binding to cells of eight human tumor lines was sensitive to N-glycan branching. Staining intensity revealed pronounced branch-mode-dependent differences in four cases. Biodistribution profiles in mice uncovered dramatic changes in clearance rates with prolonged serum presence associated with type II branching of sialylated N-glycans and markedly increased uptake of neoglycoproteins with type I-branched N-glycans into liver, spleen, heart and lungs. This part of the study is relevant for rational glycoengineering of pharmaproteins. In general, our study supports the concept to view details of N-glycan structure, here branching, as a means to modulate ligand properties. (c) 2005 Elsevier B.V. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available