Aspartic Proteases and Regulators

As the smallest class, aspartic proteases nevertheless play an important role in health and disease. For example, beta and gamma secretases are the two enzymes necessary to release A beta peptides from the Alzheimer's precursor protein. BACE-1 & 2 and Cathepsin D & E all have beta secretase activity and Presenilin is the catalytic subunit of the gamma secretase complex that contains three other integral membrane proteins. As a general protease inhibitor, alpha 2-Macroglobulin is able to inhibit all four classes of proteases by a unique trapping mechanism.