Shadow-cast electron microscopy of fibrinogen with antibody fragments bound to specific regions.
Shadow-cast electron microscopy of fibrinogen with antibody fragments bound to specific regions.
复制标题
纤维蛋白原的阴影投射电子显微镜，抗体片段结合到特定区域。
DOI：
10.1073/pnas.78.1.200
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发表时间：
1981
影响因子：
11.1
通讯作者：
Doolittle,RF
中科院分区：
文献类型：
--
作者：
Price,TM;Strong,DD;Rudee,ML;Doolittle,RF
将与对纤维蛋白原分子的各个部分具有特异性的抗体Fab片段混合的人纤维蛋白原样本进行钨阴影投射并通过电子显微镜检查。典型的三结节纤维蛋白原分子时，观察到Fab片段被省略，或当片段从非免疫血清被使用。在实验性纤维蛋白原-Fab制剂中，发现大量分子具有额外的结节。在来自针对片段E的抗体的Fab片段的情况下，额外的结节附着于纤维蛋白原分子的中心球。类似地，抗片段D制剂产生在末端球上衍生化的分子。来自针对纤维蛋白原α链的溴化氰片段（残基241-476）产生的抗体的片段也导致末端结构域的排他性衍生化，尽管在这些情况下，额外的材料通常通过间隙与末端球体离散地分离。这些实验证实了长期以来的观点，即三结节纤维蛋白原分子的中心结构域对应于纤溶酶衍生片段E，末端球体对应于片段D。此外，羧基末端三分之二的α链从分子的末端突出，这是根据间接生物化学数据推断的。
Specimens of human fibrinogen mixed with Fab fragments of antibodies that were specific for various portions of the fibrinogen molecule were tungsten shadow-cast and examined by electron microscopy. Typical trinodular fibrinogen molecules were observed when Fab fragments were omitted or when fragments from nonimmune sera were used. In the experimental fibrinogen-Fab preparations, a significant number of molecules were found with an extra nodule. In the case of Fab fragments from antibodies directed to fragment E, the additional nodule was attached to the central sphere of the fibrinogen molecule. Similarly, anti-fragment D preparations yielded molecules that were derivatized on the terminal spheres. Fragments from antibodies raised against a cyanogen bromide fragment of fibrinogen alpha chains (residues 241-476) also led to exclusive derivatization of the terminal domains, although in these cases the additional material was often separated discretely from the terminal sphere by a gap. These experiments confirm longstanding notions that the central domain of a trinodular fibrinogen molecule corresponds to the plasmin-derived fragment E and that the terminal spheres correspond to fragments D. Moreover, the carboxy-terminal two-thirds of alpha chains protrude from the extremities of the molecule, as had been inferred on the basis of indirect biochemical data.