Constitutive and Regulated α -secretase Cleavage of Alzheimer's Amyloid Precursor Protein by a Disintegrin MetalloproteaseSven Lammich, Elzbieta Kojro, Rolf Postina, Sandra Gilbert, Roland Pfeiffer, Marek Jasionowski, Christian Haass and Falk Fahrenholz · Proceedings of the National Academy of Sciences of the United States of America · 1999