Collagenase: What is it? History, Specificity, Molecular Characteristics, Composition and Applications

They are endopeptidases that digest native collagen in the triple helix region.

Collagens are the main fibrous component of animal extracellular connective tissue . Bacterial collagenases differ from vertebrate collagenases in that they exhibit broader substrate specificity.

Unlike animal collagenases that separate collagen in its native triple helix conformation. Bacterial collagenase is unique in that it can degrade both water-insoluble native collagens and water-soluble denatured ones.

It can attack almost all types of collagen and is capable of making multiple indentations within triple helix regions.

History

Much of what is known today about the characteristics of clostridial collagenase comes from pioneering studies in the 1950s by Mandl, Seifter, Harper, and their associates, and subsequent classification work by Van Wart and Bond.

In 1959, Worthington offered the first commercially available collagenase isolated from Clostridium histolyticum. At that time, only a crude enzyme preparation was offered.

After Clostridium histolyticum collagenases were first prepared by Mandl et al., Studies from the late 1950s to the mid-1980s found that several separable collagenases exist and the characteristics and stabilities of these fractions were characterized. partially.

The molecular weights of these seven collagenases were found to vary between 68 kDa and 130 kDa, and were classified as Class I or Class II, based on a variety of properties.

These classes were found to differ with respect to their activities, stabilities, and amino acid composition, but they share many similarities.

Until 1962, most of the interest in collagenases focused on clostridial collagenases. In that year, Gross and Lapiere obtained evidence for a collagenase in frog tadpole tissue culture media, which was the discovery of the first vertebrate collagenase.

After this discovery, a large number of collagenases were found in marine life, other bacteria, amphibians, and mammals.

Other studies of collagenases from human and other mammalian sources have been reported, and continue to be actively studied to better understand the pathology and treatment of human disease.

Of particular interest is the relationship between collagenase and rheumatoid arthritis, metastasis, wound debridement, herniated disc treatment, angiogenesis, tissue repair, and cirrhosis.

Specificity

Hyperreactive sites where Class I and Class II enzymes initially attack all three types of collagen were identified by French et al. The cleavage sites are all at the Yaa-Gly bonds in the Gly-X collagen repeating sequence.

The ability of clostridial collagenases to digest native triple helix collagens I, II, and III in a mixture of small peptides is their main distinguishing factor. This is accomplished by making multiple splits in the triple helix. Digestion is completed by hydrolyzing these fragments into a mixture of small peptides.

In contrast, vertebrate collagenases initiate collagenolysis by making a single cleavage in the three alpha chains, after which the attack on those alpha chains is very limited. Gelatinases and other proteases then carry out collagenolysis only after denaturation of the triple helix.

Molecular characteristics

Collagenase is produced by two separate and distinct genes in Clostridium histolyticum. Both genes have been cloned and sequenced. The col G gene codes for type I collagenase, a 936 amino acid peptide.

The col H gene codes for type II collagenase, a 1021 amino acid peptide. These genes share 72% identity, and proteins share 43% identity.

Both gene products can be present as two or more isoforms that differ in molecular weight. Therefore, crude collagenase mixtures can contain six to eight species of different molecular weights ranging from 68 to 130 kDa.

Substrate specificity studies have shown that the col G gene prefers natural substrates such as intact collagen, compared to col. H gene product On the contrary, the col H gene product acts preferentially on short synthetic substrates (FALGPA) in relation to the col G.

Composition

Clostridium collagenases represent unusually large metalloproteases, a family of proteases that share a zinc-containing motif in the center of the active site.

Protein Access Numbers:

  • Q9X721 (ColG, Theory).
  • Q46085 (ColH, Theoretical).

CATH classification (v. 3.2.0):

  • Class: Mainly beta.
  • Topology: Gelatin rolls.

Molecular weight:  68-130 kDa.

Optimal PH:  6.3-8.5.

Isoelectric point

  • 5.63 (ColG, theorem).
  • 5.58 (ColH, Theoretical).

Extinction coefficient:

  • 159,970 cm  -1  M  -1  (ColG, theorem).
  • 150.130 cm  -1   M  -1   (ColH, theoretical).
  • And  1%, 280  = 13.20 (ColG, Theoretical).
  • E  1%, 280  = 13.40 (ColH, Theoretical).

Activators:

  • Like  2+ .
  • Zn 2+.

Inhibitors:

  • EDTA, EGTA.
  • Cysteine, histidine.
  • TDT.
  • 2-mercaptoetanol.
  • o – fenanthrolina.
  • Hg  2+  , Pb  2+  , Cd  2+  , Cu  2+ .
  • Not inhibited by DFP or serum.

Collagenase is also inhibited by α2    macroglobulin, a large plasma glycoprotein Nagase et al. and Stricklin and Welgus report on natural collagenase inhibitors.

The human skin enzyme is inhibited by human serum, but granulocyte collagenase is not. Human serum contains alpha  2  macroglobulin and alpha  1  -antitrypsin that can inhibit certain collagenases, as well as a third inhibitor reported by Woolley et al.

Collagenase A has also been shown to be photoactive in the presence of methylene blue.

Applications

  • Isolation of adipocytes, hepatocytes, and cells from lung, epithelium, and adrenal tissue.
  • Isolation of cardiomyocytes and cells of bone, cartilage, muscle, thyroid and endothelium.
  • Isolation of breasts and various other soft tissues.
  • Isolation of human and porcine pancreatic islet cells.
  • Treatment of tissues with crude collagenase, with its mixture of proteolytic activities, provides a gentle and selective digestion of the intercellular matrix with little damage to cells or loss of viability.
  • Collagenase AFA is suitable for applications that need to avoid the introduction of animal-derived pathogens in bioprocessing procedures.