Albumin-bound quercetin repairs vitamin E oxidized by apolipoprotein radicals in native HDL3 and LDL
Albumin-bound quercetin repairs vitamin E oxidized by apolipoprotein radicals in native HDL3 and LDL
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DOI：
10.1021/bi701419d
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发表时间：
2007-12-11
期刊：
影响因子：
2.9
通讯作者：
Morliere, Patrice
中科院分区：
文献类型：
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作者：
Filipe, Paulo;Patterson, Larry K.;Morliere, Patrice
在含有α-生育酚（α-TocOH）的HDL 3的次要部分中，Br-中心点（2）-自由基阴离子对载脂蛋白A-I和A-II的Trp和Tyr残基的选择性单电子氧化产生相应的sernioxidized物质，TyrO（中心点）和（中心点）Trp。内源性α TocOH对TyrO（中心点）的修复产生α-生育酚氧基自由基（α TocO（中心点））。快速光谱研究表明，最初形成的两个群体（代表80%的α TocO（中心点））在几秒钟内被生理相关浓度下与人血清白蛋白（HSA）结合的槲皮素修复，速率常数为3.0 x 10（6）和1.5 x 10（5）M-1 s（-1）。观察到HSA结合的槲皮素自由基（（中心点）Q（B））的形成。在缺乏α-TocOH的HDL 3颗粒的主要部分中，TyrO（中心点）和（中心点）Trp被游离的和HSA结合的槲皮素修复。在均含有α TocOH的LDL颗粒中，α TocO（中心点）自由基通过修复载脂蛋白B中产生的Tyr O（中心点）自由基在毫秒时间尺度内形成。然后，75%的初始α TocO（中心点）在数秒内被HSA结合的槲皮素修复（速率常数：2.0 × 10（6）M-1 s（-1））。HSA结合的槲皮素也可以修复（中心点）Trp自由基。在O-2-饱和溶液中，未被超氧阴离子自由基修复的α TocO（中心点）自由基部分（超过50%）可被HSA结合的槲皮素修复，形成O（中心点）Q（B），但在LDL中的修复程度远低于HDL。
In the minor fraction of HDL3 containing alpha-tocopherol (alpha TocOH), selective one-electron oxidation of Trp and Tyr residues of apolipoproteins A-I and A-II by Br-center dot(2)- radical-anions produces the corresponding sernioxidized species, TyrO(center dot) and (center dot)Trp. Repair of TyrO(center dot) by endogenous alpha TocOH generates the a-tocopheroxyl radical (alpha TocO(center dot)). Fast spectroscopic studies show that two populations representing 80% of alpha TocO(center dot) initially formed are repaired over several seconds with rate constants of 3.0 x 10(6) and 1.5 x 10(5) M-1 s(-1) by quercetin bound to human serum albumin (HSA) at physiologically relevant concentration. Formation of HSA-bound quercetin radicals ((center dot)Q(b)) is observed. In the major fraction of HDL3 particles lacking alpha TocOH, TyrO(center dot) and (center dot)Trp are repaired by free and HSA-bound quercetin. In LDL particles which all contain alpha TocOH, alpha TocO(center dot) radicals are formed in the millisecond time scale by repair of TyrO(center dot) radicals produced in apolipoprotein B. Then, 75% of initial alpha TocO(center dot) are repaired over seconds by HSA-bound quercetin (rate constant: 2.0 x 10(6) M-1 s(-1)). HSA-bound quercetin can also repair (center dot)Trp radicals. In O-2-saturated solutions, the fraction of alpha TocO(center dot) radicals (more than 50%) not repaired by superoxide radical-anions can be repaired by HSA-bound quercetin with formation Of (center dot)Q(b) but to a much lesser extent in LDL than in HDL.