Evidence for post-translational changes in rat liver ferritin.

Analysis of rat liver isoferritins labelled by NaH14CO3 injection shows that acidic isoferritins decay exponentially, while activity in more basic isoferritins rises over 2-3 days. This suggests that isoferritins of low pI become more basic by post-translational modification, occurring over the whole life time of the protein.