桑叶超氧物歧化酶（SOD）的研究

分别用高速冷冻离心法和低速室温离心法提取了桐乡青、湖桑１９７、团头荷叶白、尖头荷叶白４个品种的顶芽、第５位和第１０位叶以及蚕沙残桑叶的ＳＯＤ粗酶液，然后用ＮＢＴ光还原法和聚丙烯酰胺凝胶电泳分别分析测定了它们的活性及其同工酶。试验结果表明：用高速冷冻离心法和低速室温离心法提取的ＳＯＤ，其活性无显著差异；同一叶位的桑叶ＳＯＤ活性在不同桑品种之间无显著差异；同一桑品种不同叶位的ＳＯＤ活性有显著差异；蚕沙残桑叶的ＳＯＤ活性与第１０位叶的ＳＯＤ活性相当。发现桑叶中有３～４种ＳＯＤ同工酶。

STUDY ON THE SUPEROXIDE DISMUTASE FROM MULBERRY MORUS ALBA LINNAEUS LEAVES

In this investigation,the SOD was extracted from terminal bud leaves,the 5thleaves,the 10th leaves and waste leaves in the litter of fifth instar silkworm of fourdifferent mulberry varieties,Tongxiangqing,Tantouheyebai,Jiantouheyebai andHusang 197 by two methods,namely,high speed and cold centrifugation, and normalspeed and room temperature centrifugation. SOD activity was determined by NBT lightreducing reaction,and the iosenzyme of the SOD was analyzed by polyacrylamideelectrophoresis.The experiment showed that activity of the SOD extracted with twodifferent methods has no significant difference,and that from the same leaf order ofdifferent varieties has no significant difference either,But that from the different leaforder of the same varieties has significant difference.And the SOD activity from thewaste mulberry was nearly equal to that of the 10th leaves.The experiment also showedthat the mulberry leaves have four kinds of iosenzyme of the SOD.