Effect of exchange of amino acid residues of the surface region of the PST-01 protease on its organic solvent-stability.
The PST-01 protease from an organic solvent tolerant Pseudomonas aeruginosa has high stability and activity in the presence of various organic solvents. The structure gene of the PST-01 protease was amplified by the error-prone PCR method. The mutated proteases were incubated in the presence of acetonitrile. By measuring remaining activities, two kinds of mutated PST-01 proteases of which the stabilities were changed were selected. These mutations hardly changed the profile of the activity and stability at various pHs. Their activity and stability at higher temperatures were slightly lower than those of the wild-type PST-01 protease. The stabilities of the mutated enzymes in the presence of various organic solvents were greatly reduced. In both the mutated PST-01 proteases, amino acids located at the surface of the enzyme had been substituted.
Ogino
Hiroyasu
H
Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan. ogino@chemeng.osakafu-u.ac.jp
Uchiho
Takeshi
T
Doukyu
Noriyuki
N
Yasuda
Masahiro
M
Ishimi
Kosaku
K
Ishikawa
Haruo
H
D019943:Amino Acid Substitution; D000596:Amino Acids / Q000737:chemistry*; D001665:Binding Sites; D004789:Enzyme Activation; D004795:Enzyme Stability; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D016297:Mutagenesis, Site-Directed; D009930:Organic Chemicals / Q000737:chemistry*; D011485:Protein Binding; D012697:Serine Endopeptidases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D012997:Solvents / Q000737:chemistry*; D013329:Structure-Activity Relationship; D013499:Surface Properties; D013696:Temperature
D000596:Amino Acids; D009930:Organic Chemicals; D012997:Solvents; C038495:Pseudomonas serine proteinase; D012697:Serine Endopeptidases