Cystic fibrosis liver sialyltransferase.

The activity of sialytransferase with regard to the glycoprotein substrates asialofetuin and 
asialo-ovine submaxillary mucin was determined in normal, pathological control, and cystic 
fibrosis liver homogenates. Cystic fibrosis and pathological livers have about 40% 
of the average normal specific activity for sialytransferase. Several properties of 
cystic fibrosis sialytransferase were investigated and compared to those of the 
normal liver enzyme (Alhadeff et al. 1977). The pH optima curves 
were similar, but cystic fibrosis sialyltransferase appears to be more thermolabile 
than the normal liver enzyme. Isoelectric focusing studies revealed that the 
three most basic forms of sialyltransferase which are found in normal 
livers are deficient or absent in most cystic fibrosis liver. The 
data suggest that altered glycoprotein-sialyltransferases may be present in cystic fibrosis 
livers, probably a secondary effect due to general liver pathology. 