A major, six‐armed glycoprotein from embryonic cartilage.
A major, six‐armed glycoprotein from embryonic cartilage.
复制标题
来自胚胎软骨的一种主要六臂糖蛋白。
作者：
L. Vaughan;S. Huber;M. Chiquet;K. Winterhalter
在这里，我们描述了一种主要的软骨糖蛋白的分离和鉴定，该蛋白与典型的透明软骨成分如II型和I型胶原一起从鸡胚胸骨中共同提取。在聚丙烯酰胺凝胶电泳法中，它以大分子量蛋白质(大于10(6)道尔顿)的形式迁移，还原时在205/195kd处产生明显的双峰，在220和170kd处产生较小的条带。在速率区带离心法中，完整的分子以13S组分的形式沉积，表明溶液中存在高度延伸的构象。在这些特性上，它与肌腱抗原非常相似，肌腱抗原是最近在包括软骨在内的许多胚胎组织中发现的一种糖蛋白。使用针对肌腱抗原的单抗(M1)的免疫印迹证实了这一身份。旋转阴影分子的电子显微镜显示了一种不同寻常的六臂结构，在形式和尺寸上与最近发现的细胞纤维连接蛋白制剂的污染物六臂臂无法区分。这些结构可以被M1抗体修饰，表明六臂臂是肌腱抗原。这种延伸的、潜在的多价分子可以提供理想的底物来连接高度水化的组织中广泛分布的成分，如软骨。
Here we describe the isolation and identification of a major cartilage glycoprotein which is co‐extracted along with typical hyaline cartilage components such as collagen types II and IX from chicken embryo sternum. In polyacrylamide gel electrophoresis it migrates as a high molecular mass protein (greater than 10(6) daltons) which on reduction gives rise to a prominent doublet at 205/195 kd and minor bands at 220 and 170 kd. The intact molecule sediments as a 13S component in rate zonal centrifugation, indicative of a highly extended conformation in solution. In these properties it closely resembles myotendinous antigen, a glycoprotein recently detected in a number of embryonic tissues, including cartilage. This identity was confirmed by immunoblotting using a monoclonal antibody (M1) specific for myotendinous antigen. Electron micrographs of the rotary shadowed molecule revealed an unusual six‐armed structure, indistinguishable in form and dimensions from hexabrachion, a recently discovered contaminant of cellular fibronectin preparations. These structures could be decorated with the M1‐antibody, demonstrating that hexabrachion is myotendinous antigen. This extended, potentially multivalent molecule could provide an ideal substrate to connect widely spaced components in a highly hydrated tissue such as cartilage.