The Apo-E gene regulates the production of a protein which is an active transport mechanism for cholesterol out of the brain. The function of this protein is to transport cholesterol out of the brain. Apo-E 3 seems intermediate. The difference between Apo-E2, E3 and E4 is that E2 has two cysteines, in E3 one Cysteine is replaced by an arginine, in E4 both cysteines are replaced by arginine. He explained that unlike cysteine the arginine does not pick up mercury since it contains no sulfur.
Mercury loves sulfur more than other molecules.
It will drop whatever it is attached to and bind with sulfur. So with the E2 people, who are less likely to get AD have a protein that carries mercury as well as cholesterol out of the brain by binding mercury with sulfur seats. Those with Apo-E3 are intermediate AD have a lesser number of sulfur seats. Those who are more likely to develop AD have less seats available. Once mercury gets into their brains it cannot get out.