Isolation and Identification of Cartilage-derived Factor (CDF) and its Precursor.

除了已知的激素和生长因子，一些功能性基质成分已被怀疑在软骨形成表达的控制中发挥重要作用。本文报道了首次鉴定和克隆的组织特异性功能基质成分25 kDa糖蛋白（chondromodulin-I，ChM-I）的结构和生物活性。在碱性成纤维细胞生长因子（FGF）存在下，从胎牛软骨中纯化的ChM-Ⅰ显着刺激培养的生长板软骨细胞的DNA合成。牛ChM-Ⅰ cDNA显示成熟ChM-Ⅰ由121个氨基酸组成，有3个可能的糖基化位点，编码为一个较大前体的C-末端部分。北方印迹分析显示，ChM-Ⅰ mRNA仅在软骨中表达。

Besides known hormones and growth factors, some functional matrix components have been suspected to play important roles in the control of chondrogenic expression. Here I report the structure and bioactivity of 25 kDa glycoprotein (chondromodulin-I, ChM-I) as a tissue-specific functional matrix component identified and cloned for the fist time. ChM-I purified from fetal bovine cartilage markedly stimulated DNA synthesis of cultured growth-plate chondrocytes in the presence of basic Fibroblast Growth Factor (FGF). Bovine ChM-I cDNA revealed that mature Ch-M-I consists of 121 amino acids with three possible glycosylation sites and is coded as the C-terminal part of a larger precursor. On northern blot analysis, expression of ChM-I mRNA was observed only in cartilage.