J. Biol. Chem., Vol. 267, Issue 17, 11760-11768, 06, 1992
Polyglycosylceramides with branched N-acetyllactosamine sequences are synthesized by the human pancreatic carcinoma cell line PANC-1
T Barnett and GF Clark
Department of Biochemistry, Eastern Virginia Medical School, Norfolk 23501.
We have metabolically labeled the human pancreatic tumor cell line PANC- 1
with high specific activity tritiated sugar precursors to study the
expression of glycosphingolipids by this cell type. We have used a
combination of detergent solubilization, exhaustive protease digestion,
ceramide glycanase digestion, and reverse-phase chromatography to isolate
glycosphingolipid-derived oligosaccharides specifically labeled in their
component sugars. A significant proportion of the oligosaccharides derived
from polar glycosphingolipids were of high molecular mass (greater than
2000 Da). The results of compositional studies, lectin affinity
chromatography, and methylation analysis suggested that this high molecular
weight fraction consists of lactosaminoglycan type oligosaccharides derived
from polyglycosylceramides. There are on average three beta 1-6 linked N-
acetyllactosamine branches attached to the polylactosamine backbone in this
type of glycosphingolipid-derived oligosaccharide. The majority of the
oligosaccharides also contain 1-2 mol of sialic acid that are linked alpha
2-3 to penultimate galactose. The results indicate that PANC-1 cells, like
human colorectal tumor cells, express highly extended neolacto type
glycosphingolipids. However, the lactosaminoglycan sequences are highly
branched, unlike those associated with colorectal tumor cells.
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
