Lithium and viruses.

The activity of the lithium ion against DNA type viruses is explained by its competition with magnesium ions. Magnesium acts as the cofactor of the enzymes responsible for the replicative building of viral proteins and nucleosides. When lithium replaces magnesium, it appears to render the polymerase enzymes impotent. Association constants for lithium and magnesium with ATP, a pertinent model substance, are of the same order of magnitude, which shows that interference must occur. Some chelating agents such as PAA have antiviral properties, and their action can be explained also if the delta G of their binding of magnesium is more negative than that of magnesium with ATP. This again displaces the magnesium as the enzymatic cofactor, thereby halting viral replication.