Baysal E, Sullivan S G, Stern A
Department of Pharmacology, New York University School of Medicine, NY 10016.
Free Radic Res Commun. 1989;8(1):55-9. doi: 10.3109/10715768909087972.
The binding of Fe3+ to red cell membranes was studied in a system in which lipid peroxidation was proportional to Fe3+ concentration. Binding of Fe3+ was evaluated by labeling with 59FeCl3 and measurement of NMR water-proton relaxation times. Labeling with 59Fe showed that 95% of the Fe3+ was membrane bound at 100 microM FeCl3 in a 1.5 mg protein/ml membrane suspension. Both spin-lattice (T1) and spin-spin (T2) relaxation times decreased with increasing Fe3+ concentration. Addition of red cell membrane suspensions largely prevents the Fe3+ effect on relaxation times. Charge transfer to Fe3+ may occur at the membrane binding site with resultant decrease in the Fe3+ effect on water-proton relaxation times. These studies support the hypothesis that Fe3+ binds to the membrane and generates free radicals at the binding site.
在脂质过氧化与Fe3+浓度成正比的系统中，研究了Fe3+与红细胞膜的结合。通过用59FeCl3标记并测量核磁共振水-质子弛豫时间来评估Fe3+的结合。用59Fe标记表明，在1.5 mg蛋白质/ml膜悬浮液中，当FeCl3浓度为100 microM时，95%的Fe3+与膜结合。自旋晶格（T1）和自旋自旋（T2）弛豫时间均随Fe3+浓度的增加而降低。添加红细胞膜悬浮液在很大程度上可防止Fe3+对弛豫时间的影响。在膜结合位点可能发生向Fe3+的电荷转移，从而使Fe3+对水-质子弛豫时间的影响降低。这些研究支持了Fe3+与膜结合并在结合位点产生自由基的假说。
