LAUSR

The purification and characterization of PGM (Phosphoglucomutase) from Cordyceps militaris ( C. militaris ) was investigated. PGM was purified using a combination of ultrafiltration, salting-out and ion exchange chromatography resulting in 4.23-fold enhancement of activity with a recovery of 20.01%. Molecular mass was 50.01 kDa by SDS-PAGE. The optimal activity was achieved at pH 7.5 and 30 °C with NADPH as substrate. The results showed that SDS, DTT Li + , Cu 2+ , Na + , Mn 2+ and Al 3+ were effective PGM inhibitors; whereas glycerol, Zn 2+ , Mg 2+ , Ca 2+ , Fe 2+ and Fe 3+ could enhance the activity of PGM, and the K m and V max values were 11.62 mmol/L and 416.67 U/mL, respectively. At the same time, qRT-PCR was used to test the changes of mRNA transcription level of PGM gene encoding under two fermentation conditions: basic medium and optimized medium. The relative quantitative results of PGM target genes resulting in 2.60-fold enhancement than the control group.