Purification and characterization of metallothionein and its activation of pyridoxal phosphokinase in trout (Salmo gairdneri) brain.

1. Brain metallothionein was isolated and purified for the first time from rainbow trout. 2. Brain metallothionein exhibited an elution volume (Ve/Vo) of 2.0, had a molecular weight of 6762 Daltons, and contained a zinc content of 9 micrograms/mg protein. 3. Brain pyridoxal phosphokinase was isolated and assayed for the first time in rainbow trout. 4. Zinc (0.20 microM) or zinc metallothionein (6-30 microM) stimulated the activity of brain pyridoxal kinase in a linear fashion. 5. The results of these studies are interpreted to suggest that in trout brain zinc metallothionein may participate in metabolism of vitamin B6 and formation of pyridoxal phosphate, the active coenzyme.