Structural characteristics of human substantia nigra neuromelanin and synthetic dopamine melanins
Structural characteristics of human substantia nigra neuromelanin and synthetic dopamine melanins
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DOI：
10.1046/j.1471-4159.2000.0752583.x
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发表时间：
2000-12-01
影响因子：
4.7
通讯作者：
Gerlach, M
中科院分区：
文献类型：
--
作者：
Double, KL;Zecca, L;Gerlach, M
神经黑素(NM)是一种复杂的聚合物色素，主要存在于人黑质的多巴胺能神经元中，其结构仅有部分特征，其合成途径尚不清楚。我们用核磁共振和红外光谱研究了从黑质分离的人NM的结构，并与人工合成的多巴胺黑色素进行了比较，用生化分析研究了这些样品中的蛋白质和多巴胺能成分。在酸解NM样品后，检测到了少量的DOPA、多巴胺和各种氨基酸。这些发现提示NM结构中含有多肽成分。NM似乎还含有各种未知的结构成分，可能来自于多巴胺的氧化。人的NM在结构上不同于合成的多巴胺黑色素，但人和合成的NM都包括芳香主干。有趣的是，人类NM和合成黑色素也含有很大比例的脂肪族结构。我们的结果表明，NM是一种比单独通过多巴胺自氧化形成的合成多巴胺黑色素更复杂的色素。
Neuromelanin (NM) is a complex polymer pigment found primarily in the dopaminergic neurons of the human substantia nigra, The structure of NM is only partially characterized, and its synthesis pathway remains unknown, We used nuclear magnetic and infrared spectroscopy to examine the structure of human NM isolated from the substantia nigra compared with synthetic dopamine melanins, Biochemical analyses were used to investigate proteinaceous and dopaminergic components in these samples. Following acid hydrolysis of NM samples, small amounts of DOPA, dopamine, and a variety of amino acids were measured. These findings suggest a peptide component in NM structure. NM also appears to contain a variety of unidentified structural components possibly derived from the oxidation of dopamine. Human NM differs structurally from synthetic dopamine melanin, but both human and synthetic NM include an aromatic backbone. It is interesting that both human NM and synthetic melanin also contain a large proportion of aliphatic structures. Our results suggest that NM is a more complex pigment than synthetic dopamine melanin formed via dopamine autoxidation alone.