关键词: 北京棒杆菌, 酶学性质, 突变体, 天冬氨酸激酶

Abstract: By analyzing the structure of aspartate kinase (AK), we screened the Pro184 site that might affect the binding of allosteric inhibitors, and the mutant strain P184Q was successfully screened by saturation sitedirected mutagenesis. The enzymatic properties show that the V_max of P184Q was 3 times higher than that of widetype (WT), n=1.39 indicating that the positive cooperativity of the substrate decreased, the K_m value decreased simultaneously, and the affinity of the substrate increased. The optimum pH of P184Q was 6.5. The optimum temperature of P184Q was
 25 ℃. The halflife period was 2.8 h. Futhermore, P184Q show strong resistance to metal ions, organic solvent and inhibitors Thr+Met, Lys+Met, Thr+Lys and Lys.

Key words: aspartate kinase, mutant, Corynebacterium pekinense, enzymatic property