Metalloproteinases are characterized by the retention of a quantitative metal ion, a protease containing metal ions in the active center. This enzyme retains a quantitative metal ion throughout the purification process and cannot be removed by conventional methods. However, if a chelating agent such as EDTA is present during the purification process, metal ions are also lost to lose the enzyme activity. Only the addition of this ion can restore its activity. Some metalloproteinases and their metal ions are: trypsin (Ca), chymotrypsin (Ca), carboxypeptidase (Zn), neutral protease (Zn), thermolysin (Ca, Zn), collagen Enzyme (Ca, Zn). The optimum pH of these enzymes is generally between 7 and 9.
Trypsin is a kind of protease which is a serine proteolytic enzyme extracted from the pancreas of cattle, sheep and pigs. In vertebrates, it acts as a digestive enzyme. In the pancreas, the precursor of trypsin is synthesized and secreted as a component of pancreatic juice. It is decomposed by enterokinase or trypsin to activate trypsin. It is an endopeptidase that can bind the polypeptide chain. The carboxyl side in the middle lysine and arginine residues is cleaved. It not only acts as a digestive enzyme, but also inhibits the decomposition of precursors of other enzymes such as chymotrypsin, carboxypeptidase, and phospholipase, and activates it. It is the most specific protease and it is an indispensable tool in determining the amino acid arrangement of proteins.
Figure 1. Protein structure of trypsin.
Chymotrypsin is about the same as trypsin. They are all involved in protein amino acid metabolism enzymes and also a hydrolase. Chymotrypsin is a digestive enzyme component of pancreatic juice that acts in the duodenum where it undergoes proteolysis, protein and polypeptide breakdown. Chymotrypsin is a proteolytic enzyme (serine protease) that acts in the digestive system of many organisms in vivo.
Figure 2. Protein structure of Chymotrypsin.
Carboxypeptidases (CPs) are a class of peptide exonucleases that specifically degrade and release free amino acids from the C-terminus of the peptide chain. Carboxypeptidase A, B is a digestive enzyme. A type of exonuclease that specifically degrades from the C-terminus of the peptide chain to release free amino acids. It exists in the living body as a zymogen. Commonly used are A, B, C and Y, and 4 carboxypeptidases. In the field of medicine. Since carboxypeptidase is widely involved in the biochemical reaction of the body, it can be diagnosed and treated by the detection of carboxypeptidase in vivo, and can also be used for degradation of undesirable substances (toxins, etc.) in medicine.
Figure 3. Protein structure of carboxypeptidases.
Neutral protease (Dispase) is a metal neutral protease that is non-mammalian free of animal origin (AOF). Its mild proteolysis makes it gentle to the cell membrane and is therefore particularly suitable for the preparation of primary cells and subculture (subculture) cell culture. The protease is also used as a secondary enzyme in cell separation and tissue dissociation applications, typically in conjunction with collagenase.
Thermolysin are the most suitable microorganisms with a growth temperature above 45 °C. Thermophilic microorganisms not only can withstand high temperatures, but also can grow and reproduce at high temperatures, and their living environment requires higher temperatures. This is different from the heat resistance of common spore bacteria. The common spore bacteria form spore resistance under high temperature. When the environmental conditions are restored, the spores germinate into vegetative bodies, while the spores do not have reproductive ability, but only the stress-resistant dormant body.
Figure 4. Protein structure of thermolysin.
Collagen enzyme specifically hydrolyzes the three-dimensional helical structure of native collagen under physiological pH and temperature conditions without damaging other proteins and tissues. The chemical nature of collagenase is a protein. Therefore, it is very sensitive to various factors such as temperature, pH and protein denaturation. It is highly susceptible to external conditions and changes its conformation and properties. Human endogenous collagenase refers to the collagenase in the human body, such as the epithelial tissue of the gums, the contact membrane, the synovial membrane of the joint, the intervertebral disc, and the collagenase, which is decomposed in the body. The process plays an indispensable role. Medicinal collagenase refers to a white or off-white sterile freeze-dried powder biological preparation obtained by extracting, purifying and purifying from the fermentation broth of Clostridium solani using high-tech means of biopharmaceuticals.
Figure 5. Protein structure of Collagen enzyme.
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