aspartaattiproteaasi

Aspartylproteaasi is a class of enzymes that catalyze the hydrolysis of peptide bonds using an aspartate residue in the active site as a nucleophile. These enzymes are characterized by the presence of two aspartate residues in their active site, which work together to cleave peptide bonds. Aspartylproteases are found in a wide range of organisms, from bacteria and viruses to plants and animals. They play crucial roles in various biological processes, including protein processing, digestion, and immune responses.

A well-known example of an aspartylprotease is pepsin, which is found in the stomach of vertebrates and is essential for the digestion of proteins. Another important example is renin, an enzyme involved in the regulation of blood pressure. In viruses, aspartylproteases are often involved in the maturation of viral particles, as seen in the human immunodeficiency virus (HIV) protease. Inhibition of viral aspartylproteases is a key strategy in the treatment of HIV infection.

The mechanism of action for aspartylproteases typically involves a general acid-base catalysis, where one aspartate residue acts as a general acid to protonate the carbonyl oxygen of the peptide bond, making it more susceptible to nucleophilic attack. The second aspartate residue acts as a general base, deprotonating a water molecule to form a hydroxide ion, which then attacks the carbonyl carbon. This forms a tetrahedral intermediate, which is subsequently cleaved to release the products and regenerate the enzyme. Aspartylproteases are a diverse group of enzymes with significant physiological and pathological importance.