Comparison of structural and chemical properties of black and red human hair melanosomes
Comparison of structural and chemical properties of black and red human hair melanosomes
复制标题
DOI：
10.1562/2004-08-03-ra-259.1
复制
发表时间：
2005-01-01
影响因子：
3.3
通讯作者：
Simon, JD
中科院分区：
文献类型：
--
作者：
Liu, Y;Hong, L;Simon, JD
黑色和红色人发中的黑素体通过各种化学和物理技术分离和表征。通过HI水解得到的4-氨基-羟基酚丙氨酸（褐黑素的标志物）和通过KMnO 4/H+氧化得到的吡咯-2，3，5-三羧酸（真黑素的标志物）的不同产率表明，黑发中的黑素体是真黑素体，而红发中的黑素体主要是褐黑素体。原子力显微镜显示，真黑素体和褐黑素体分别具有椭圆形和球形。真黑素体在从角蛋白基质提取时保持结构完整性，而褐黑素体倾向于分裂。黑毛真黑素体的平均氨基酸含量为14.6 +/- 0.5%，这归因于黑素体颗粒中捕获的内部蛋白质。红毛黑素体含有超过44%的氨基酸含量，即使在广泛的蛋白水解消化。这种高含量的氨基酸和红毛黑素体保存的完整性差表明，除了那些被困在黑色素物质中的蛋白质外，一些蛋白质可能与黑色素成分共价键合。溶液溶解测定表明，针对氨基酸含量调整的每克样品的黑色素吸光度对于黑发黑素体比对于红发黑素体大2.9倍。金属分析揭示了大量的不同的重金属离子绑定到两种类型的黑素体。铜（II）和锌（II）的含量相似，但铁（III）的含量是红头发黑素体的四倍。C-13固态核磁共振光谱和红外光谱，并被证明是强大的技术，用于辨别的氨基酸含量的差异，5，6-二羟基吲哚-2-羧酸：5，6-二羟基吲哚的比例，和交联度的颜料。这些光谱结果和化学降解数据之间观察到极好的一致性。
Melanosomes in black and red human hair are isolated and characterized by various chemical and physical techniques. Different yields of 4-amino-hydroxyphenolanaline by HI hydrolysis (a marker for pheomelanin) and pyrrole-2,3,5-tricarboxylic acid by KMnO4/H+ oxidation (a marker for eumelanin) indicate that the melanosomes in black hair are eumelanosomes, whereas those in red hair are mainly pheomelanosomes. Atomic force microscopy reveals that eumelanosomes and pheomelanosomes have ellipsoidal and spherical shapes, respectively. Eumelanosomes maintain structural integrity upon extraction from the keratin matrix, whereas pheomelanosomes tend to fall apart. The black-hair eumelanosomes have an average of 14.6 +/- 0.5% amino acids content, which is attributed to the internal proteins entrapped in the melanosomes granules. The red-hair melanosomes contain more than 44% of amino acid content even after extensive proteolytic digestion. This high content of amino acids and the poorly reserved integrity of red-hair melanosomes suggest that some proteins are possibly covalently bonded with the melanin constituents in addition to those that are entrapped inside the melanin species. Soluene solubilization assay indicates the absorbance of melanin per gram of sample, adjusted for the amino acid content, is a factor of 2.9 greater for the black-hair melanosomes than the red-hair melanosomes. Metal analysis reveals significant amounts of diverse heavy metal ions bound to the two types of melanosomes. The amount of Cu(II) and Zn(II) are similar but Fe(III) content is four times higher in the red-hair melanosomes. C-13 solid-state nuclear magnetic resonance spectra and infrared spectra are presented and are shown to be powerful techniques for discerning differences in the amino acid contents, the 5,6-dihydroxyindole-2-carboxylic acid: 5,6-dihydroxyindole ratio, and the degree of cross-linking in the pigment. Excellent agreement is observed between these spectral results and the chemical degradation data.