Definition of Beta-secretase

1. Take the Tummy Trouble Quiz
2. Digestive Disease Myths Slideshow Pictures
3. Hemorrhoids Slideshow: Does Everyone Have Them?

Beta-secretase: An enzyme that appears to be directly involved in the early development of Alzheimer's disease. Beta-secretase is a protease (an enzyme that catalyses the splitting of interior peptide bonds in a protein). Beta-secretase acts by trimming off a protein protruding from a brain cell. This small snip is thought to be the first step in the buildup of microscopic balls of debris known as amyloid that are toxic to brain cells. The brain cells (neurons) gradually die and with them slowly go the person's memory and other mental faculties.

The discovery of beta-secretase was made in 1999 and may lead to the development of drugs designed to block this enzyme and hopefully block the progression of Alzheimer's disease.

For additional information:

1. Vassar R. et al. Beta-Secretase Cleavage of Alzheimer's Amyloid Precursor Protein by the Transmembrane Aspartic Protease BACE. Science (Oct 22 1999) 286: 735-740. (The original research report.)
2. Pennisi E. Enzymes Point Way to Potential Alzheimer's Therapies. Science (Oct 22 1999) 286: 650-651. (The accompanying commentary on the discovery.)