Excepting prions, I'm not aware of any environmental factors changing a protein's function.

edit: regarding your comment below, the evidence in the Nature paper is fairly strongly in favor of a conformational change, though its all circumstantial evidence until they have a crystal structure.

I'm a doc, I'm all about environment influencing disease. I was primarily responding to what seemed to be an overly environmental view on your part. This article puts sime non-trivial evidence in the genetics camp.