Hofer G, Lichtenberg D, Kostner G M, Hermetter A
Department of Biochemistry and Food Chemistry, Technische Universität Graz, Austria.
Clin Biochem. 1996 Oct;29(5):445-50. doi: 10.1016/0009-9120(96)00061-6.
Oxidation of polyunsaturated fatty acids in lipoproteins is supposed to play a crucial role at the early stages of atherogenesis. The polyunsaturated lipids (PUFAs) become oxidized and, thus, the degree and rate of lipid oxidation depend on their concentration and, probably, on the lipid moiety to which they are attached.
To determine the relative oxidation susceptibilities of sphingo- and glycerolipid-bound fatty acyl chains, we used fluorescent analogs of the respective compounds, in which one natural fatty acyl chain was replaced by fluorescent diphenylhexatriene propionic acid.
Oxidation susceptibilities of the fluorescent acyl chains in the presence of Cu2+ or AAPH depended, in general, on the phospholipid to which they were bound and the lipoprotein. Phospholipids were oxidized faster in HDL than in LDL or Lp(a). Plasmalogens were more susceptible to oxidation than phosphatidylcholine and sphingomyelin.
Thus, HDL and plasmalogens may be considered as preferred targets of lipid oxidation before the bulk of polyunsaturated phospholipids (mainly phosphatidylcholine) in LDL is subject to free radical attack.
脂蛋白中多不饱和脂肪酸的氧化被认为在动脉粥样硬化发生的早期阶段起着关键作用。多不饱和脂质（PUFAs）会被氧化，因此，脂质氧化的程度和速率取决于它们的浓度，可能还取决于它们所连接的脂质部分。
为了确定鞘脂和甘油磷脂结合的脂肪酰链的相对氧化敏感性，我们使用了各自化合物的荧光类似物，其中一条天然脂肪酰链被荧光二苯基己三烯丙酸取代。
在存在Cu2+或AAPH的情况下，荧光酰链的氧化敏感性通常取决于它们所结合的磷脂和脂蛋白。HDL中的磷脂比LDL或Lp(a)中的磷脂氧化得更快。缩醛磷脂比磷脂酰胆碱和鞘磷脂更容易被氧化。
因此，在LDL中大部分多不饱和磷脂（主要是磷脂酰胆碱）受到自由基攻击之前，HDL和缩醛磷脂可能被视为脂质氧化的首选靶点。
