摘要
研究了蔗糖脂肪酸脂 (SFE)对离体和活体大豆蔗糖酶活力和构象的影响。当SFE的浓度大于1 .0mmol/L后 ,开始激活离体蔗糖酶的活力。在大豆的开花期和结荚期 ,SFE可以增加蔗糖酶的活力。荧光实验结果表明 ,在小于 2mmol/L时 ,SFE不改变蔗糖酶的荧光最大发射峰峰位和峰高。施用SFE后 ,大豆叶片中果糖、葡萄糖和蔗糖酶的含量 ,分别是对照的 1 70 %± 1 0 % ,1 90 %± 1 0 % ,和2 60 %± 2 0 % ;而蔗糖的含量几乎不变。对蔗糖酶的SDS 凝胶电泳图进行扫描分析的结果表明 ,经SFE处理后的蔗糖酶含量比对照高两倍左右。这些结果说明SFE可以显著增加活体蔗糖酶的活力 ,但活力的增加既不是因为蔗糖酶构象的改变 ,也不是蔗糖 (作为底物 )诱导所致 。
Effects of sucrose fatty acid ester (SFE) on the activity of invertase of soybean leaf in vivo and in vitro have been studied. The activity of invertase was increased by SFE when its concentration was over 1.0 mmol/L. SFE could elevate the activity of invertase in vivo during the periods of flowering and pod filling. Experiment with fluorescence of invertase gave the result that SFE at concentrations up to 2 mmol/L could hardly change the maximum emission and fluorescence intensity of invertase. The fructose, glucose and invertase contents of soybean leaves after application of SFE were 170%±10%,190%±10%,and 260%±20% of the control, respectively. But there were little changes in sucrose content. The result of scanning on SDS PAGE gels showed that the invertase content after treatment by SFE was twice as high as that of the control. It is suggested that SFE can increase the activity of invertase in vivo distinctly, which is not caused by a change in invertase conformation or by the induction of sucrose, but by an increase in invertase content.
基金
ThisworkwassupportedbytheNationalNaturalScienceFoundationofChina (29473117) .
关键词
蔗糖酶
蔗糖脂肪酸酯
酶活力
构象
大豆
invertase, sucrose fatty acid ester, enzymatic activity, conformation
