NOVEL TISSUE-SPECIFIC--BASEMENT MEMBRANE COMPONENT

一种限制性组织的基膜相关蛋白 已经使用单克隆抗体检测特异性， 命名为merosin。 美洛辛仅与以下物质结合存在： 胎盘基底膜（滋养层BM），肌肉 （肌纤维BM）和外周神经（雪旺细胞BM），如 通过间接免疫荧光证实。 的片段 约55kD的裂体蛋白从胃蛋白酶消化的 胎盘，并用于提高多克隆兔抗血清， 裂殖蛋白 兔抗体对人体组织的染色与 单克隆抗体也与肌肉反应， 小鼠组织中的外周神经BM。 完整的组织形式 merosin的大小约为75 kd， 直接或间接与层粘连蛋白结合。 我们将获得完整的氨基酸序列的merosin 蛋白质和cDNA测序的组合。 55kd胃蛋白酶 可以以毫克量分离的裂殖蛋白片段， 将用于获取蛋白质序列信息。 cDNA克隆 将从现有的胎盘cDNA中选择 使用特异性抗体和合成寡核苷酸构建文库。 将从胎盘提取物中分离出完整的裂球蛋白， 研究merosin与其他BM的相互作用， 细胞外基质蛋白和细胞。 的生物合成 将在细胞和组织培养中研究merosin， 成熟蛋白亚基的大小和数量信息 如果它在沉积到细胞外之前被处理， 矩阵 裂殖蛋白在基底中的定位 正常成人组织中的膜将使用 免疫电镜 发育性表达 将通过免疫荧光在小鼠中研究裂殖蛋白。 类似地，胎盘中的裂球蛋白的存在形式不同， 物种和人类肿瘤将进行研究。 表达 将与特定的功能相关， 随着细胞和组织的分化程度 表达merosin。 这项研究可能会产生关于组织特异性的重要信息。 BM的功能。

A basement membraneassociated protein of restricted tissue specificity has been detected using monoclonal antibodies and named merosin. Merosin is present only in association with basement membranes (BM) of placenta (trophoblast BM), muscle (muscle fiber BM), and peripheral nerve (Schwann cell BM), as evidenced by indirect immunofluorescence. A fragment of merosin of about 55 kd was isolated from a pepsin digest of placenta and used to raise a polyclonal rabbit antiserum to merosin. The rabbit antibodies stain human tissues identically to the monoclonal antibodies and also react with muscle and peripheral nerve BMs in mouse tissues. The intact, tissue form of merosin appears to have a size of about 75 kd and may interact directly or indirectly with laminin. We will obtain a complete amino acid sequence of merosin by a combination of protein and cDNA sequencing. The 55 kd pepsin fragment of merosin, which can be isolated in milligram amounts, will be used to obtain protein sequence information. cDNA clones will be selected from an existing placenta lambdagtll cDNA library using specific antibodies and synthetic oligonucleotides. Intact merosin will be isolated from placental extracts and used to study the interaction of merosin with other BM and extracellular matrix proteins and with cells. The biosynthesis of merosin will be studied in cell and tissue culture to obtain information on size and number of subunits of the mature protein and if it is processed before being deposited in the extracellular matrix. The localization of merosin in relationship to the basement membrane in normal adult tissue will be studied using immunoelectron microscopy. Developmental expression of merosin will be studied in mouse by immunofluorescence. Similarly, the presence of merosin in placentas form different species and in tumors in man will be investigated. The expression of merosin will be correlated with the particular functions and with the degree of differentiation of the cells and tissues expressing merosin. This study may yield important information on tissuespecific functions of BMs.