Nataf V, Mercier P, De Néchaud B, Guillemot J C, Capdevielle J, Lapointe F, Le Douarin N M
Institut d'Embryologie Cellulaire et Moléculaire, CNRS, Collège de France, Nogent-sur-Marne.
Exp Cell Res. 1995 May;218(1):394-400. doi: 10.1006/excr.1995.1171.
We have biochemically characterized the antigen recognized by the melanoblast/melanocyte early marker (MelEM) monoclonal antibody (Mab) which labels early melanoblasts and melanocytes in the avian embryo [1]. While among the neural crest derivatives MelEM Mab is strictly specific for the melanocytic lineage, some endodermal derivatives such as hepatocytes react with this Mab. Since MelEM Mab immunoprecitates a protein of the same relative mass from both liver extracts and melanocytes, we immunopurified MelEM protein from liver extract of quail embryos at 10 days of incubation. The N-terminal sequence of this protein being blocked, we determined three internal peptide sequences. Our study reveals that the MelEM protein is an Alpha class subunit of glutathione S-transferase which is common to hepatocytes and to neural crest-derived pigment cells during their differentiation.
我们已经对黑素母细胞/黑素细胞早期标志物（MelEM）单克隆抗体（Mab）所识别的抗原进行了生化特性分析，该抗体可标记禽类胚胎中的早期黑素母细胞和黑素细胞[1]。虽然在神经嵴衍生物中，MelEM Mab对黑素细胞谱系具有严格的特异性，但一些内胚层衍生物如肝细胞也会与该Mab发生反应。由于MelEM Mab能从肝脏提取物和黑素细胞中免疫沉淀出相同相对分子质量的蛋白质，我们从孵化10天的鹌鹑胚胎肝脏提取物中免疫纯化了MelEM蛋白。由于该蛋白的N端序列被封闭，我们测定了三个内部肽段序列。我们的研究表明，MelEM蛋白是谷胱甘肽S-转移酶的α类亚基，在肝细胞和神经嵴衍生的色素细胞分化过程中是共同存在的。
