Evidence for a correlation between ambient cholesterol levels and soluble plasma sialyltransferase enzyme activity.

While soluble forms of the sialyltransferase (sialyl-T) enzyme have been detected in significant quantities in serum, the exact source(s) of the enzyme, or the factors controlling its secretion are poorly understood. In this study, we have examined the relationship between ambient plasma cholesterol concentrations and sialyl-T-activities and also levels of constituent plasma sialoglycoproteins (SGP). There was an inverse relationship between levels of the alpha 2, 6 sialyl-T enzyme and both total plasma cholesterol and HDL, although no such relationship was observed for the alpha 2,3 enzyme. While there was no correlation between total cholesterol and the levels of plasma SGPs, there was an inverse relationship between the HDL component and alpha 2,3 SGPs.