The Study On Synthetic Nattokinase Gene Transformation Of Melon

Nattokinase, which was extracted from the Japanese traditional food—atto and found to be a strong fibrinolytic serine enzyme,was derived from the Bacillus Subtilis. Nattokinase can effectively decompose the main component of thrombus—fibrin. In the study, the optimized nattokinase gene was synthesized according the plant preferential codons. The recombinant plasmid pPZP221(E8-sNK-NOS,35S-sNK-NOS) was transformed into melon via pollen-tube pathway transformation method. DNA was isolated from the melon and subsequently analysed by PCR. RNA was extracted from the melon and subsequently analysed by RT-PCR. The analysis revealed that sNK gene was transformed into melon, which proved that the transgenic melon was obtained. Nattokinase enzyme activity was assayed by fibrin plate method and30transgenic fruits have nattokinase activity in135transgenic fruits. The nattokinase activity of transgenic fruits after storing different times (5d,10d,20d) was measured. The result showed that with the extension of the fruit storage time, the activity was decreased. The nattokinase activity of non-transgenic fruit was not detected. The transcriptional expression assessed by RT-PCR revealed that30transgenic melon was expressed, which indicated that sNK gene had been integrated into melon. This is the elementary study for further research on melon as functional food of dissolving thrombus.