Abstract
The oxidative stability of enzymes is mostly dependent on the stability of the Cys and Met residues. Three single point mutants with Met/Leu substitutions in D-amino acid oxidase (DAAO, EC 1.4.3.3) from the yeast Trigonopsis variabilis (TvDAAO) are prepared and characterized. The positions for the amino acid residue substitutions are selected based on multiple alignment of different DAAO amino acid sequences and analysis of the three-dimensional structure of TvDAAO. It is shown that the substrate specificity profile ischanged for all of the mutants. The KM values for the small and bulky D-amino acidsare increased and decreased, respectively. One of the Met/Leu substitutions results in a two- to threefold increase in thermal stability as compared to the wild-type enzyme. A method for the determination of TvDAAO stability in the presence of hydrogen peroxide is developed and the oxidative stability of wild-type and mutant TvDAAOs is studied. It is shown that none of thethree mutations changes the oxidative stability of the enzymes.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
