?Fast isoamylases? in the parotid saliva of children with cystic fibrosis and heterozygous carriers

Abstract

On electrophoresis, parotid saliva always exhibits a basic pattern of 6 isoamylases. Additional faster migrating isoamylases occur in varying numbers. These "fast isoamylases" are generated, at least in part, by deamidation. Compared with juvenile and adult controls, a significantly greater number of "fast isoamylases" was found in the parotid saliva of children with cystic fibrosis and their healthy heterozygous parents. A shift in the equilibrium between amidation and deamidation is discussed in terms of its possible connection with the metabolic defect responsible for cystic fibrosis.

Premature Senescence in Cultured Skin Fibroblasts from Subjects with Cystic Fibrosis

“…203 carrier adults (Il). (ii) Parotid saliva from subjects with CF and their heterozygous parents contains a greater number of "fast isoamylases" than do controls (12). It is thought that these isozymes of amylase migrate faster in electrophoretic fields because of deamidation of asparagine and glutamine residues (13).…”