Studies on the synthesis of plasma membrane proteins of fibroblasts from patients with cystic fibrosis.

The characteristic increased salinity of sweat and other abnormalities of exocrine secretions 
in patients with cystic fibrosis (CF) suggest the possibility of a 
disturbed functioning of the plasma membrane in this disease. Several lines 
of evidence indicate that fibroblasts express the presence of the CF 
genotype. Therefore these cells were used in an in vitro study 
directed at determining whether the manifestations of CF might be related 
to an alteration of one or more of the protein components 
of the plasma membrane. In order to evaluate the synthesis of 
these components, growing fibrosblasts from patients with CF and normal subjects 
were briefly exposed to either 14C- or 3-H-leucine. Their plasma membranes 
were then isolated and subjected to analysis in a nondetergent acrylamide 
gel system. Coelectrophoresis of differentially labeled preparations revealed the absence of 
a detectable abnormality in the synthetic rates of any of the 
more than 30 resolved protein species. 