title: Improving the acidic stability of a methyl parathion hydrolase by changing basic residues to acidic residues.
abstract: The acidic stability of a methyl parathion hydrolase (Ochr-MPH) was improved by selectively changing basic amino acids to acidic ones. Mutation sites were selected based on the position-specific amino acid replacement probabilities (more than or equal to 0.2) and the entropy of each site (more than or equal to 0.8). Three mutants (K208E, K277D, and K208E/K277D) were more stable than the wild-type (WT). Their half-lives at pH 5.0 were 64, 68, 65 min, respectively, whereas that of WT was 39 min. The acidic stability of proteins may therefore be improved by changing selected basic amino acid residues to acidic ones.
authors.affiliation: Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China. hl_8796@sina.com
authors.forename: Lu
authors.initials: L
authors.lastname: Huang
authors.forename: Ping
authors.initials: P
authors.lastname: Wang
authors.forename: Jian
authors.initials: J
authors.lastname: Tian
authors.forename: Huachen
authors.initials: H
authors.lastname: Jiang
authors.forename: Ningfeng
authors.initials: N
authors.lastname: Wu
authors.forename: Peilong
authors.initials: P
authors.lastname: Yang
authors.forename: Bin
authors.initials: B
authors.lastname: Yao
authors.forename: Yunliu
authors.initials: Y
authors.lastname: Fan
mesh_terms: D019943:Amino Acid Substitution; D002942:Circular Dichroism; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D008743:Methyl Parathion / Q000378:metabolism*; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D050505:Mutant Proteins / Q000737:chemistry / Q000378:metabolism; D042041:Ochrobactrum / Q000201:enzymology; D010744:Phosphoric Monoester Hydrolases / Q000737:chemistry* / Q000378:metabolism*; D011487:Protein Conformation
chemical_list: D050505:Mutant Proteins; D008743:Methyl Parathion; D010744:Phosphoric Monoester Hydrolases