KINETICS OF THERMOINACTIVATION OF D-AMINO ACID OXIDASE OPADAAO1 FROM THE OGATAEA PARAPOLYMORPHA DL-1 YEAST

Abstract

Our earlier annotation of genome of the yeast Ogataea parapolymorpha DL-1 made it possible to identify ve genes of potential D-amino acids oxidases. All opadaao1 - opadaao5 genes were cloned and expressed in E. coli. Four OpaDAAO1- OpaDAAO4 enzymes were obtained in highly puri ed form and their catalytic properties were studied. It was found that among all DAAOs described in the literature so far, the enzyme OpaDAAO1 has the highest catalytic constant kcat with D-Ala, which makes it promising for practical applications. However, in addition to good catalytic parameters, effective application of the enzyme in practice requires high stability and knowledge of the inactivation mechanism, including at elevated temperatures. In this work we studied the effect of elevated temperatures on the stability of OpaDAAO1. The enzyme was shown to have high thermal stability in comparison with majority of other D-amino acid oxidases. The kinetics of OpaDAAO1 inactivation at different temperatures, initial concentrations of the enzyme, and in the presence of exogenous FAD were studied. A possible kinetic scheme of inactivation was proposed based on the data obtained.