STRUCTURAL SIMILARITIES BETWEEN THY-1 ANTIGEN FROM RAT-BRAIN AND IMMUNOGLOBULIN
STRUCTURAL SIMILARITIES BETWEEN THY-1 ANTIGEN FROM RAT-BRAIN AND IMMUNOGLOBULIN
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DOI：
10.1038/282341a0
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发表时间：
1979-01-01
期刊：
影响因子：
64.8
通讯作者：
REID, KBM
中科院分区：
文献类型：
--
作者：
CAMPBELL, DG;WILLIAMS, AF;REID, KBM
细胞相互作用的分子基础尚不清楚，但人们普遍认为膜载配体和受体之间的直接相互作用是重要的。在分化过程中表达受调控的膜分子是这些作用的候选者。细胞相互作用的功能分析是如此复杂，以至于通过功能分析纯化分子的传统生化方法不适用。有人认为，最好的方法是首先识别细胞表面分子，然后根据分子特征或利用分子或抗体干扰功能系统来尝试识别功能。Thy-1 （θ）抗原已被广泛研究，因为它在某些细胞类型中大量表达，而在其他细胞类型中不存在。Thy-1可能是鼠脑和胸腺中含量最多的细胞表面糖蛋白，但其功能尚不清楚（见文献2）。在结构研究的基础上，我们认为Thy-1可能是显示细胞相互作用配体的候选者，而所涉及的特定决定因素可能是碳水化合物3。在此，我们对大鼠脑Thy-1的氨基酸序列和圆二色性（CD）谱进行了进一步的结构研究。结果表明，该分子具有类似于Ig结构域的结构，这与酶的功能不一致。分子的存在可能是为了被识别，其中的决定因素可能是蛋白质或碳水化合物。
The molecular basis of cellular interactions is poorly understood but it is commonly believed that direct interactions between membrane-borne ligands and receptors are important. Membrane molecules whose expression is regulated in differentiation are candidates for these roles. Functional assays for cellular interactions are of such complexity that the traditional biochemical methods of purifying a molecule by following a functional assay are not applicable. It can be argued that the best approach is first to identify cell-surface molecules and then to attempt to identify functions on the basis of their molecular characteristics or by using the molecules or antibodies to them to perturb functional systems1. The Thy-1 (theta) antigen has been much studied because it is expressed in large amounts on some cell types but is absent from others. Thy-1 is probably the most abundant cell surface glycoprotein of rodent brain and thymus, yet its function is unknown (reviewed in ref. 2). On the basis of structural studies it was suggested that Thy-1 would be a candidate for displaying ligands for cell interactions and that the specific determinants involved might be carbohydrate3. We present here a preliminary report of further structural work dealing with the amino acid sequence and circular dichroism (CD) spectrum of rat brain Thy-1. The results suggest that this molecule has a structure resembling an Ig domain, which would not be consistent with an enzymatic function. The molecule probably exists to be recognised and the determinants involved could be protein or carbohydrate.