Alzheimer's disease

The invention relates to Alzheimer's disease (AD), and particularly, although not exclusively, to Amyloid-beta (?ß or Abeta), and variants thereof. The invention also includes kits comprising a variant ?ß, and to uses of these kits and ?ß variants in ?ß studies, for example in assays and methods for screening novel compounds for use in treating AD. Alzheimer's disease (AD) is characterized by the deposition of ?ß in extracellular amyloid plaques, as well as the intracellular accumulation of tau in neurofibrillary tangles in the brain. Mutations in ?ß and the Amyloid precursor protein (APP) are linked to familial AD, and therefore ?ß is thought to play an important role in the disease process. Numerous studies have been conducted to try to better understand how ?ß is involved in the neurodegeneration observed in AD patients and the symptoms of the disease. Some of these studies have been conducted in transgenic animals whilst others have used biomimetic membranes, cultured neurons or animal injection to investigate the direct effect of oligomeric and fibrillar ?ß in these systems.