Collagenases

Collagenases are Zn2+-dependent endopeptidases in the matrix metalloproteinase (MMP) family that specifically cleave native collagens, the main structural components of the extracellular matrix. They act on collagen types I, II, and III by cutting the triple helix at a defined site, generating two fragments and thereby initiating collagen degradation. Collagenases are produced by a range of organisms, including humans (MMP-1, MMP-8, MMP-13) and several bacteria (notably Clostridium histolyticum ColG and ColH).

In humans they are synthesized as inactive zymogens and activated extracellularly. They are zinc-dependent metalloproteases; the active site coordinates a Zn2+ ion, with calcium ions contributing to enzyme stability. Substrate specificity is limited to intact collagen triple helices; denatured collagen (gelatin) is also susceptible but at different rates.

Inhibition and regulation: activity is restrained by tissue inhibitors of metalloproteinases (TIMPs). Expression and activation are regulated by cytokines, growth factors, and mechanical cues. Physiological roles include normal tissue remodeling during development, wound healing, and angiogenesis. Pathologically, excessive collagenase activity contributes to arthritis, fibrosis, and cancer invasion due to degradation of ECM and basement membranes.

Applications: Bacterial collagenases are used in bioconversion, tissue dissociation for cell isolation, and enzymatic debridement in wound care; in research, MMP inhibitors and recombinant collagenases are tools for ECM studies. Industrially, collagenases are used to tenderize meat and process collagenous materials.