Title: Thermolysin
CAS Registry Number: 9073-78-3
Additional Names: Bacillus thermoproteolyticus neutral proteinase; EC 3.4.24.27
Literature References: Proteolytic enzyme of mol wt 37,500 that hydrolyzes protein bonds on the N-terminal side of hydrophobic amino acid residues. Contains a zinc atom essential for activity and four Ca2+ ions essential for thermal and conformational stability. Isoln from Bacillus thermoproteolyticus: S. Endo, J. Ferment. Technol. 40, 346 (1962). Properties and amino acid composition: Y. Ohta et al., J. Biol. Chem. 241, 5919 (1966). Site of enzymatic hydrolysis: Y. Ohta, Y. Ogura, J. Biochem. 58, 607 (1965). Substrate specificity studies: H. Matsubara et al., Biochem. Biophys. Res. Commun. 21, 242 (1965); 24, 427 (1966); K. Morihara, H. Tsuzuki, Biochim. Biophys. Acta 118, 215 (1966). Stability studies: Y. Ohta, J. Biol. Chem. 242, 509 (1967). Inhibition studies: H. Matsubara et al., Biochem. Biophys. Res. Commun. 34, 719 (1969); J. Murphy et al., Arch. Biochem. Biophys. 202, 405 (1980). Purification: H. Matsubara, Methods Enzymol. 19, 642 (1970). Structure studies: K. Titani et al., Nature 238, 35 (1972); B. W. Matthews et al., ibid. 37, 41; P. M. Colman et al., J. Mol. Biol. 70, 701 (1972). Function of the metal ions: J. Feder et al., Biochemistry 10, 4552 (1971); G. Voordouw, R. S. Roche, ibid. 14, 4667 (1975); R. S. Roche, G. Voordouw, Crit. Rev. Biochem. 5, 1 (1978). Effect of the histidyl residue on the mechanism of action: S. Blumberg et al., Isr. J. Chem. 12, 643 (1974); M. K. Pangburn, K. A. Walsch, Biochemistry 14, 4050 (1975). Review: Experientia 26, Suppl., 31-59 (1976).
Properties: Crystals. uv max: 280 nm (e 66,300). Optimum pH 7.0-8.5; stable at pH 6.0-9.0. The refrigerated lyophilized enzyme is stable for months; frozen enzyme soln can be kept for weeks without significant loss of activity. Not deactivated at 65°, but loses half of its activity upon heating at 80° for 1 hr.
Absorption maximum: uv max: 280 nm (e 66,300)
Use: In studies of protein sequences. |