FREE RADICAL SCAVENGING AND DNA DAMAGE PROTECTION BY METALLOTHIONEIN
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

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.