金属硫蛋白清除自由基及其对自由基引起的核酸损伤保护作用的研究

通过化学反应体系产生ＯＨ＾－和Ｏ＾－２自由基，采用荧光和化学发光检测体系，比较研究了不同亚型及不同结合金属的金属硫蛋白（ＭＴ）清除自由基能力的大小。结果表明，对于同一亚型，Ｚｎ结合ＭＴ清除自由基的能力大于Ｃｄ结合ＭＴ；同一结合金属的ＭＴ，ＭＴ１清除自由基的能力大于ＭＴ２。通过比较ＺｎＭＴ１与谷胱甘肽（ＧＳＨ）及超氧化物歧化酶（ＳＯＤ）清除自由基的能力大小发现，ＺｎＭＴ１清除ＯＨ的能力是ＧＳＨ的１０

FREE RADICAL SCAVENGING AND DNA DAMAGE PROTECTION BY METALLOTHIONEIN

The effccts of metaallothionein(MT) on free radiCal scavenging and DNA damage protection were studied. Fluorescence reaction of OH with benzonic acid and chemiluminescence reaction of O with luminol were used as the detection systems. The abilities of free radical scavenging of ZnMT1, ZnMT2, CdMT1, and CdMT2 were tested. It was found that Zn boUnding MT has greater abilities to scavenge free radical than Cd bounding MT. As for MT isoforms, MT1 has greater abilities to scavenge free radical than MT2, suggesting that they may play different roles in vivo. The most efficient MT, ZnMT1, for free radical scavenging was compared with GSH and SOD. Results indicated that ZnMT1 is 100 times more effective in OH scavenging than GSH, while it is about 25 and 0.01 time as effective in O scavenging as GSH and SOD. In addition, the protection effat of MT on DNA damage caused by OH was examined.