Researcher:
Karen Abbott, postdoctoral research associate, Complex Carbohydrate Research Center, University of Georgia, Athens
Project:
Breast cancer biomarker discovery
Problem:
Abbott works with proteins whose glycosylation patterns differ in normal versus cancerous cells. She needed a method that could enrich and identify these glycoproteins.
Solution:
Breast cancer epithelial cells express higher levels of an enzyme that creates a specific sugar structure called beta-1,6-branched N-linked oligosaccharide. That modification is absent from normal breast epithelia. Says Abbott, "That means the glycosylation of the protein is the malignant marker, not the protein itself." To identify proteins containing this structure, Abbott employed a specific sugar-binding protein - a lectin, which acts like a sugar-specific antibody - to isolate intact proteins bearing the modification ( J Proteome Res, ASAP Article, 10.1021/pr700792g, Feb. 14, 2008).
Abbott treated intact cell extracts with a biotinylated form of the lectin, called L-PHA, capturing the glycoprotein-lectin complexes on paramagnetic streptavidin ...
