From Wikipedia, the free encyclopedia
Thermolysin EC 3.4.24.27 is a thermostable neutral metalloproteinase enzyme produced by the gram negative bacteria Bacillus thermoproteolyticus.[1] It requires one zinc ion for enzyme activity and four calcium ions ions for structural stability.[2] Thermolysin specifically catalyzes the hydrolysis of peptide bonds containing hydrophobic amino acids. However thermolysin is also widely used for peptide bond formation through the reverse reaction of hydrolysis.[3] Thermolysin is the most stable member of a family of metalloproteinases produced by various Bacillus species. These enzymes are also termed 'neutral' proteinases or thermolysin -like proteinases (TLPs).
[edit] Synthesis
Like all bacterial extracellular proteases thermolysin is first synthesised by the bactrium as a pre-proenzyme.[4] Thermolysin is synthesized as a pre-proenzyme consisting of a signal peptide 28 amino acids long, a pro-peptide 204 amino acids long and the mature enzyme itself 316 amino acids in length. The signal peptide acts as a signal for translocation of pre-prothermolysin to the bacterial cytoplasmic membrane. In the periplasm pre-prothermolysin is then processed into prothermolysin by a signal peptidase. The prosequence then acts as a molecular chaperone and leads to autocleavage of the peptide bond linking pro and mature sequences. The mature protein is then secreted into the extracellular medium.[5]
[edit] Structure
Thermolysin consists of a beta pleated sheet rich N-terminal domain and a alpha helical rich C-terminal domain. These two domains are connected by a central alpha helix.
[edit] References
- ^ Endo, S. (1962). "Studies on protease produced by thermophilic bacteria". J. Ferment. Technol. 40: 346-353.
- ^ Tajima M, Urabe I. et al. (1976). "Role of calcium ions in the thermostability of thermolysin and Bacillus subtilis var. amylosacchariticus neutral protease". Eur. J. Biochem. 64 (1): 243-247. PMID 819262.
- ^ Trusek-Holownia A. (2003). "Synthesis of ZAlaPheOMe, the precursor of bitter dipeptide in the two-phase ethyl acetate-water system catalysed by thermolysin". J. Biotechnol. 102 (2): 153-163. PMID 12697393.
- ^ Yasukawa K, Kusano M, Inouye K. (2007). "A new method for the extracellular production of recombinant thermolysin by co-expressing the mature sequence and pro-sequence in Escherichia coli". Protein Eng. Des. Sel. 20 (8): 375-383. PMID 17616558.
- ^ Inouye K, Kusano M. et al. (2007). "Engineering, expression, purification, and production of recombinant thermolysin". Biotechnol. Annu. Rev. 13: 43-64. PMID 17875473.
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