- Subtilisin refers to a family of serine proteases originally isolated from Bacillus subtilis and related bacteria. It is a non-specific endopeptidase that belongs to the S8 family of serine proteases (subtilases) and is characterized by its ability to hydrolyze peptide bonds in a wide range of protein substrates. Subtilisin operates through a catalytic triad mechanism involving serine, histidine, and aspartate residues, similar to that found in trypsin and chymotrypsin.
- Subtilisin is secreted extracellularly by Bacillus species and functions optimally at alkaline pH (8–10) and elevated temperatures, reflecting its role in degrading proteins in nutrient-poor environments. Due to its broad substrate specificity, stability under harsh conditions, and proteolytic efficiency, subtilisin has become a widely used enzyme in industrial and biotechnological applications. These include its use in laundry detergents, contact lens cleaning solutions, leather processing, and peptide synthesis.
- In molecular biology, subtilisin is notably used to generate the Klenow fragment from E. coli DNA polymerase I by selectively cleaving its 5′→3′ exonuclease domain. It is also employed in limited proteolysis studies to probe protein structure and domain organization.
- Structurally, subtilisin is a globular protein that is synthesized as a pre-proenzyme and undergoes autocatalytic activation. Its robustness and modifiability have also made it a target for protein engineering, leading to development of enhanced variants with altered specificity, increased stability, or reduced autolysis.
- In summary, subtilisin is a thermostable, broad-spectrum serine protease widely utilized in research and industry for its powerful protein-degrading abilities and favorable biochemical properties.
