Alterations in human linker histone-DNA binding in the presence of aluminum salts in vitro and in Alzheimer's disease.

Sodium cations were employed to electrostatically displace chromosomal proteins from DNA. Increasing the ambient ionic concentration resulted in a characteristic dissociation pattern of chromatin which was analyzed on polyacrylamide gels. This method of sodium chloride extraction of nuclei in vitro has been used to investigate the state of compaction of chromatin in normal and Alzheimer affected neocortical nuclei and in control nuclei treated with aluminum lactate in vitro. Our results indicate that by employing specific chelating agents such as desferrioxamine in vitro, nuclear bound aluminum is particularly resistant to removal by chelation and an increase in the affinity of linker histones H1 and H1 degree for DNA occurs both in Alzheimer's disease and in the presence of aluminum salts in vitro.