Glycobiology Advance Access originally published online on May 9, 2009
Glycobiology 2009 19(8):810-812; doi:10.1093/glycob/cwp063
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
© The Author 2009. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oxfordjournals.org
Natural ligands for CD33-related Siglecs?
Departments of Medicine and Cellular and Molecular Medicine, and the Glycobiology Research and Training Center, University of California, San Diego, La Jolla, CA 92093-0687, USA
To whom correspondence should be addressed: Tel: +1-858-534-2214; Fax: +1-858-534-5611; e-mail: a1varki@ucsd.edu
| The first 150 words of the full text of this article appear below. |
Finding natural ligands involved in protein–protein interactions is relatively easy, and false-positives are rare. In contrast, the natural ligands for glycan-binding proteins (GBPs) can be quite elusive, and artifacts are common. For example, it took almost 10 years from the detection of P-selectin's glycan binding properties (Moore et al. 1991
) to reach the definitive conclusion that a certain specific posttranslationally modified form of the polypeptide PSGL-1 was the functionally relevant natural ligand for this GBP (Epperson et al. 2000). There are many reasons for such difficulties, including the fact that glycan binding is often of relatively low affinity and relies on multivalency to achieve adequate avidity, as well as the complexities of local rebinding effects such as the recently described "jump and bind" mechanisms for lectin–mucin interactions (Dam and Brewer 2008). Meanwhile, investigators continue to incorrectly state that "PSGL-1 is the ligand for P-selectin," without realizing that
Notes
Funding