两种早熟禾超氧物歧化酶活性测定的适宜条件

以冷地早熟禾 (Poacrymophila)和草地早熟禾 (P .pratensis)为材料 ,探讨光照反应时间、酶浓度以及酶反应体系等对NBT光化还原反应的影响。随着光照反应时间的延长 ,最大光还原值直线上升。 2 5min后光化还原值逐渐趋于稳定。光照反应开始后 ,酶液对NBT光化还原反应速率的抑制百分率迅速升高 ,在 15～ 2 5min时 ,酶液对NBT光化还原反应的抑制百分率保持稳定 ,2 5min后下降速率较大。光照反应时间对SOD酶活性测定的影响较大 ,确定为 2 5min较为适宜。酶浓度在 4 0～ 6 0mg/mL时光化还原值变化速率较一致。测定中反应体系NBT、核黄素的加样量以及光照强度在一定范围内时光化还原值较为稳定

The Suitable Conditions for Assaying SOD Activity by Nitrogen Blue Tetrazolium Photoreduction Method on Alopine Forage

Leaves of poa crymophila and poa Pratensis were analyzed for their superoxidedismutase content by using a photochemical assay system consisting of nitroblue tetrazolium. The effects of illumination reaction time, crude SOD extract and enzyme reaction system on the nitro blue tetrazolium photoreduction were investigated. The results show the photoreduction value linearly goes up with illumination reaction time, and the maximum can be reached in 25 min. After 25 min it keeps stable. The percentage that the crude SOD extract inhibit the reduction of NBT increases rapidly at the beginning of the illumination reaction, between 15 and 25 min after reaction it keeps stable, and after 25 min it drops dramatically. Illumination reaction time has significant effect on assay of SOD activity, 25 min is relatively suitable time required. The percentage of inhibition keeps constant at the range of 40 mg/mL to 60 mg/mL of SOD extract. When the illumination intensity and concentrations of riboflavin and NBT are fixed within certain ranges, the photoreduction will be constant basically.