Beta secretase inhibitor, molecular model. This molecule is being studied for its inhibiting effects when binding to the beta secretase enzyme (shown in C015/1972, C015/1974, C015/1975 and C015/1976). This enzyme, of the type known as aspartic-acid protease, is also known as beta-site amyloid precursor protein cleaving enzyme 1 (BACE-1). It is a transmembrane protein that is thought to play a role in Alzheimer's disease through the build up of amyloid plaques in the brain. Drugs that inhibit this enzyme may help slow the progress of the disease. Here, the atoms are colour-coded: carbon (grey), hydrogen (purple), oxygen (red), nitrogen (blue), chlorine (green), and sulphur (yellow).