Cystic fibrosis: isolation and physical properties of a salivary cystic fibrosis factor.

A ciliostatic factor has been isolated from cystic fibrosis (CF) saliva by 
dialyzing it from purified alpha-amylase prepared by a glycogen-complex method. This 
method of isolating the CF factor is an improvement over the 
previously employed heparin procedure. The activity of the isolated factor is 
proportional with concentration using the oyster gill ciliostatic assay and in 
its inhibition of mammalian glycogen debranching enzyme. The ciliostatic action of 
the factor can be reversed by heparin under certain conditions. The 
type of inhibition of the debranching enzyme by the isolated CF 
factor indicates that its chemical structure is similar to that observed 
with hydroxyalkylamines and polyamine metabolites. Physical properties of the isolated factor 
indicate that it is of low molecular weight and is labile 
as a function of pH and temperature. At neutral pH the 
conditions under which it is maintained have a direct effect on 
the length of time that it is stable. 