Fucosylation

[kzhao at BIOVX1.BIOLOGY.UCLA.EDU]

Dr. Spagnol asked the following question:

"the glycoprotein I'am study is esxpressed in a cell line and is
fucosylated in the chitobiose core. I would like to ihnibit fucosylation
of N-Linked chains in these cultured cells."

In most cases, fucosylation of core GlcNAc takes place on complex oligosacchari-des.  If you don't care about the carbohydrate structure (i.e., high mannose
vs. complex), there are two ways to avoid such a fucosylation in over-expression.  1) express it in the same cell line and in the same culture condition, exceptthat a glycosidase inhibitor (e.g. deoxymannojirimycin for mannosidase I) is 
included; or 2) express it in a mutant cell line that only produce high mannose 
structures (e.g., Lec1 CHO cells).  In my case of overexpression for a lysosomalenzyme, alpha-L-iduronidase from a secreting CHO cell line, I found a very
effective reduction of fucosylation in the presence of deoxymannojirimycin,
which does not affect my enzyme's biosynthesis, secretion, and even phosphory-
lation.

*********************************************************************************Ke-Wei Zhao, Ph.D.
*Dept. of Biological Chemistry
*UCLA School of Medicine
*Los Angeles, CA 90095-1737
********************************************************************************