PURIFICATION AND CHARACTERIZATION OF EPITHELIAL CELL MITOGENS

肝素-琼脂糖亲和层析及反相 高压液相色谱，我们已经提纯到 两种新的条件培养上皮细胞有丝分裂原同质性 M426成纤维细胞(取自人胚肺)的培养液 组织)。这两个因素在靶细胞特异性上有所不同， 一种对角质形成细胞(BALB/MK细胞系)的作用更强，而 另一种对乳腺上皮细胞系的作用更强 (b5/589)。第一种是一种单体，估计分子 重量为25-30kd，而第二个是每个链上的同源二聚体 分子量约为32kd的。一种氨基- 已经确定了这两个因子的末端蛋白质序列 它们与之前发现的任何一种 分子。如相关项目报告(Z01CP05512- 02)，根据氨基酸设计的寡核苷酸探针 序列使我们能够识别和表征cdna克隆。 包含每个因子的编码序列。单克隆化 针对这两种因子的多克隆抗体目前正在制备中。 我们还开始了对细胞表面的研究 这两种生长因子的受体。 另一种有丝分裂原已从一则商业广告中部分提纯 牛胰腺核糖核酸酶I的来源。它似乎是一种 转化生长因子生产过程中的中间体 阿尔法。确凿的证据必须等待进一步的净化。生长 抑制物质(S)已在条件化的 来自各种来源的媒体。我们正在调查他们的 与转化生长因子β家族的关系。

Using heparin-sepharose affinity chromatography and reversed-phase high pressure liquid chromatography, we have purified to homogeneity two novel epithelial cell mitogens from the conditioned media of M426 fibroblasts (derived from embryonic human lung tissue). The two factors differ in their target cell specificity, one being more potent on keratinocytes (BALB/MK cell line), while the other is more potent on a mammary epithelial cell line (B5/589). The first is a monomer with an estimated molecular weight of 25-30 kd, while the second is a homodimer with each chain having a molecular weight of approximately 32 kd. An amino- terminal protein sequence has been determined for both factors and they showed no significant homology to any previously identified molecules. As described in a related project report (Z01CP05512- 02), oligonucleotide probes designed on the basis of the amino acid sequences have enabled us to identify and characterize cDNA clones containing the coding sequence of each factor. Monoclonal and polyclonal antibodies against both factors are now being prepared. We also have initiated studies to characterize the cell surface receptors of both growth factors. Another mitogen has been partially purified from a commercial source of bovine pancreatic ribonuclease I. It appears to be an intermediate in the processing of transforming growth factor (TGF) alpha. Definitive proof must await further purification. Growth inhibitory substance(s) have been identified in the conditioned media from a variety of sources. We are investigating their relationship to the TGF beta family.