Glycosylation of VSV glycoprotein is similar in cystic fibrosis, heterozygous carrier, and normal human fibroblasts.

The single envelope glycoprotein of vesicular stomatitis virus was used as a 
specific probe of glycosyltransferase activities in fibroblasts from two cystic fibrosis 
patients, an obligate heterozygous carrier and a normal individual. Gel filtration 
of pronase-digested glycopeptides from both purified virions and infected cell-associated VSV 
glycoprotein which had been labeled with[3H] glucosamine did not reveal any 
significant differences in the glycosylation patterns between the different cell cultures. 
All 4 cell lines were apparently able to synthesize the mannose- 
and glucosamine- containing core structure and branch chains terminating in sialic 
acid which are characteristic of asparagine-linked carbohydrate side chains in cellular 
glycoproteins. Analysis of tryptic glycopeptides by anion-exchange chromotography indicated that the 
same 2 major sites on the virus polypeptide were recognized and 
glycosylated in all 4 VSV-infected cell cultures. These studies suggest that 
the basic biochemical defect(s) in cystic fibrosis is not an absence 
or deficiency in enzymes responsible for the biosynthesis of complex carbohydrate 
side chains. 