Kato Y, Maruyama W, Naoi M, Hashizume Y, Osawa T
School of Humanity for Environment Policy and Technology, Himeji Institute of Technology, Japan.
FEBS Lett. 1998 Nov 20;439(3):231-4. doi: 10.1016/s0014-5793(98)01372-6.
Lipofuscin is a yellowish brown fluorescent pigment which is sequestered within cytoplasmic granules during aging. To examine the contribution of protein oxidation to lipofuscin accumulation, we performed immunohistochemical detection of dityrosine, which is considered one of the specific markers for protein oxidation, in lipofuscin in the aged human brain using an antibody specific to dityrosine. By characterization using competitive enzyme-linked immunosorbent assay, the specificity of the antibody to dityrosine was confirmed. None of the other tyrosine-related compounds such as L-tyrosine, 3-nitrotyrosine, 3-chlorotyrosine, or 3,4-dihydroxyphenylalanine cross-reacted with the antibody. The anti-dityrosine antibody reacted with lipofuscin granules in the pyramidal neurons of the aged human brain. The results suggest that protein oxidation by free radicals and/or peroxidases may play an important role in lipofuscin accumulation.
脂褐素是一种黄褐色的荧光色素，在衰老过程中被隔离在细胞质颗粒内。为了研究蛋白质氧化对脂褐素积累的作用，我们使用针对二酪氨酸的特异性抗体，对老年人大脑脂褐素中的二酪氨酸进行了免疫组织化学检测，二酪氨酸被认为是蛋白质氧化的特异性标志物之一。通过竞争性酶联免疫吸附测定进行表征，证实了该抗体对二酪氨酸的特异性。其他酪氨酸相关化合物，如L-酪氨酸、3-硝基酪氨酸、3-氯酪氨酸或3,4-二羟基苯丙氨酸，均未与该抗体发生交叉反应。抗二酪氨酸抗体与老年人大脑锥体神经元中的脂褐素颗粒发生反应。结果表明，自由基和/或过氧化物酶引起的蛋白质氧化可能在脂褐素积累中起重要作用。
