title: Role of intermolecular disulfide bonds of the organic solvent-stable PST-01 protease in its organic solvent stability.
abstract: The PST-01 protease is secreted by the organic solvent-tolerant microorganism Pseudomonas aeruginosa PST-01 and is stable in the presence of various organic solvents. Therefore, the PST-01 strain and the PST-01 protease are very useful for fermentation and reactions in the presence of organic solvents, respectively. The organic solvent-stable PST-01 protease has two disulfide bonds (between Cys-30 and Cys-58 and between Cys-270 and Cys-297) in its molecule. Mutant PST-01 proteases in which one or both of the disulfide bonds were deleted were constructed by site-directed mutagenesis, and the effect of the disulfide bonds on the activity and the various stabilities was investigated. The disulfide bond between Cys-270 and Cys-297 in the PST-01 protease was found to be essential for its activity. The disulfide bond between Cys-30 and Cys-58 played an important role in the organic solvent stability of the PST-01 protease.
authors.affiliation: Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Sakai, Osaka 599-8531, Japan. ogino@chemeng.osakafu-u.ac.jp
authors.forename: H
authors.initials: H
authors.lastname: Ogino
authors.forename: T
authors.initials: T
authors.lastname: Uchiho
authors.forename: J
authors.initials: J
authors.lastname: Yokoo
authors.forename: R
authors.initials: R
authors.lastname: Kobayashi
authors.forename: R
authors.initials: R
authors.lastname: Ichise
authors.forename: H
authors.initials: H
authors.lastname: Ishikawa
mesh_terms: D004220:Disulfides / Q000737:chemistry*; D004795:Enzyme Stability; D004926:Escherichia coli / Q000235:genetics; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D008666:Metalloendopeptidases / Q000737:chemistry / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D016297:Mutagenesis, Site-Directed; D009930:Organic Chemicals / Q000494:pharmacology*; D010957:Plasmids / Q000235:genetics; D011550:Pseudomonas aeruginosa / Q000201:enzymology*; D012997:Solvents / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D004220:Disulfides; D009930:Organic Chemicals; D012997:Solvents; D008666:Metalloendopeptidases