To investigate the influence of Arg186 and Arg198 on the function, stability and structure of Lepidium draba peroxidase (LDP), site-directed mutagenesis was employed to substitute Asn186 and Asn198, with arginine (R), resulting in the construction of N186R and N198R mutants. The results indicated that the presence of R at position186 led to a significant decrease in specific activity and catalytic efficiency (∼65 %) compared to the native enzyme. In contrast, the replacement of N198 with R resulted in a substantial increase in both specific activity and catalytic efficiency, with increases of more than 3 and 4 times, respectively, compared to the native enzyme. Stability against heat decreased for N186R but improved for N198R, while stability against H2O2 drastically increased for both mutants, with a more pronounced observed for N198R. Fluorescence, Circular Dichroism and bioinformatics studies revealed increased flexibility in the LDP structure upon mutation compared to the native form, which was particularly highlighted in the N186R mutant. Overall, these findings suggest that the presence of R at position 198 enhances the reactivity and stability of the enzyme, which may provide insights for further enhancing LDP applications in biotechnology and medicine.