Final answer:
Collagenase is a proteolytic enzyme that digests collagen, enabling certain bacteria to penetrate host tissues, and is an example of a protease with a metal ion in its active site.
Step-by-step explanation:
An example of a proteolytic enzyme is collagenase, which contains a metal ion and specifically digests collagen, the main protein in connective tissue. Collagenase is produced by certain bacteria, such as the gram-positive Clostridium perfringens, which uses the enzyme to break down connective tissue, facilitating the invasion and spread of infection, leading to conditions such as gas gangrene. This enzyme is just one of many proteases that play a crucial role in protein catabolism, the process by which proteins are broken down into smaller peptides or amino acids.
In general, proteases can be classified by their substrate specificity or if they contain metal ions as cofactors in their active site, such as zinc in zinc metalloproteases.
Another application of proteolytic enzymes outside of biological systems is their use in household products, such as detergents and meat tenderizers, to digest and remove proteinaceous stains or to tenderize meat by breaking down animal proteins.