'Fast isoamylases' in parotid saliva of heterozygous carriers of cystic fibrosis.

An increased number of 'fast isoamylases' is found in the parotid saliva 
of children with cystic fibrosis and their heterozygous parents who are 
clinically healthy. 'Fast isoamylases' are generated, at least in part, from 
the 6 isoamylases of the basic pattern by deamidation of asparagine 
and glutamine residues. This basic pattern is present in the parotid 
saliva of all subjects we have tested so far. A shift 
in the equilibrium between amidation and deamidation processes is discussed in 
terms of its possible significance for the pathogenesis of cystic fibrosis 
and for ageing. 