发芽和提取条件对玉米胚芽中超氧化物歧化酶的诱导作用

为提高玉米超氧化物歧化酶(SOD)的活力和提取率，在不同条件下对玉米进行发芽处理，从发芽玉米中剥离胚芽，并在磷酸缓冲液中浸泡，再提取SOD，并测定SOD总活力。结果表明：玉米在30℃、有光照条件下发芽4d，剥离的40g胚芽在0.05mol/L 200mL磷酸缓冲液中浸泡36h，通过胶体磨研磨浸提1h，60℃热沉淀15min，用1.5倍－20℃的丙酮沉淀SOD，经Cellulose-DE-52层析，再经SephadexG-75层析，得到的玉米SOD比活力最高，为4487.28U/mg pro，比未发芽的玉米胚芽提取的SOD的比活力(924.18U/mg pro)提高了3.86倍。

Effects of Germination and Extraction Conditions on SOD Activity in Corn Germ

Corn germ was harvested during germination in a light or dark environment at different levels of temperature, and immersed in 0.05 mol/L phosphate buffer at pH 7.8 for different periods of time before SOD extraction and subsequent SOD activity measurement in order to explore the effects of germination and extraction conditions on SOD activity in corn germ. A maximum SOD specific activity of 4487.28 U/mg was obtained after the following operations: corn germination for 4 d under light illumination at 30 ℃, immersing of resulting corn germ in 200 mL of 0.05 mol/L phosphate buffer at pH 7.8 for 36 h, milling on a colloid miller, extraction for 1 h, thermal precipitation at 60 ℃ for 15 min, SOD precipitation from the supernatant by adding a 1.5-fold volume of －20 ℃ acetone, and sequential separation on cellulose-DE-52 and SephadexG-75 chromatographic columns, which exhibited a 3.86-fold increase in comparison with ungerminated corn germ (924.18 U/mg).