title: Thermal stable and oxidation-resistant variant of subtilisin E.
abstract: A remarkable thermal stable and oxidation-resistant mutant was obtained using the random mutagenesis PCR technique on the mutant M222A gene of subtilisin E. Sequencing analysis revealed an A was replaced by G at nucleotide 671 of the subtilisin E gene, converting the asparagine codon (AAT) to serine codon (AGT) at position 118. The half-life of M222A/N118S enzyme activity, when heated at 65 degrees C, was approximately 80 min while the half-life of M222A and wild-type subtilisin E were 13 min and 15 min, respectively. This suggested the stability of the M222A/N118S mutant was five times greater than that of the wild-type enzyme. The mutant was also as oxidation resistant as the mutant M222A of subtilisin E. These results indicated the M222A/N118S mutant is both an oxidation-resistant and a heat-stable variant of subtilisin E.
authors.affiliation: Shanghai Research Center of Biotechnology, Chinese Academy of Sciences, 200233, Shanghai, PR China. yonghuayang@hotmail.com
authors.forename: Y
authors.initials: Y
authors.lastname: Yang
authors.forename: L
authors.initials: L
authors.lastname: Jiang
authors.forename: L
authors.initials: L
authors.lastname: Zhu
authors.forename: Y
authors.initials: Y
authors.lastname: Wu
authors.forename: S
authors.initials: S
authors.lastname: Yang
mesh_terms: D000581:Amidohydrolases / Q000378:metabolism*; D019943:Amino Acid Substitution; D001412:Bacillus subtilis / Q000201:enzymology*; D004795:Enzyme Stability; D006358:Hot Temperature; D016296:Mutagenesis; D010084:Oxidation-Reduction; D010641:Phenotype; D016133:Polymerase Chain Reaction / Q000379:methods; D013381:Subtilisins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D013381:Subtilisins; D000581:Amidohydrolases; C019665:amidase