Balcavage W X, Alvager T K
Mech Ageing Dev. 1982 Jun;19(2):159-70. doi: 10.1016/0047-6374(82)90007-0.
Malonaldehyde formed by lipid oxidation is regarded as a main crosslinker in the formation of natural age pigment. To elucidate the mechanism of pigment formation the reaction of malonaldehyde with biomembranes using fluorescence spectroscopy has been studied. Rat liver mitochondrial ghosts or bovine serum albumin were reacted with malonaldehyde. In both cases two main fluorescence changes were observed: protein fluorescence decreased to 50% of its initial value in about two hours; aminoiminopropene fluorescence reached a maximum at a much slower rate. The kinetics support a two-step reaction hypothesis. First, malonaldehyde reacts with protein quenching its fluorescence. Next fluorescent interprotein aminoiminopropene (AIP) crosslinks are formed. The fluorescence lifetime value of the induced AIP fluorophore was shown to be similar to the lifetime of naturally occurring age pigment previously reported for mitochondrial ghosts prepared from aged animals (5.4 ns +/- 0.3 and 5.9 ns +/- 0.6, respectively).
脂质氧化形成的丙二醛被认为是天然老年色素形成过程中的主要交联剂。为了阐明色素形成的机制，利用荧光光谱法研究了丙二醛与生物膜的反应。大鼠肝线粒体膜囊泡或牛血清白蛋白与丙二醛发生反应。在这两种情况下，均观察到两个主要的荧光变化：蛋白质荧光在约两小时内降至其初始值的50%；氨基亚氨基丙烯荧光达到最大值的速度要慢得多。动力学支持两步反应假说。首先，丙二醛与蛋白质反应淬灭其荧光。接下来，形成荧光性的蛋白质间氨基亚氨基丙烯（AIP）交联。所诱导的AIP荧光团的荧光寿命值显示与先前报道的从老年动物制备的线粒体膜囊泡中天然存在的老年色素的寿命相似（分别为5.4 ns±0.3和5.9 ns±0.6）。
