Borsi L, Balza E, Leprini A, Ponassi M, Zardi L
Laboratory of Cell Biology, Istituto Nazionale per la Ricerca sul Cancro, Genoa, Italy.
Anal Biochem. 1991 Feb 1;192(2):372-9. doi: 10.1016/0003-2697(91)90551-4.
Fibronectin (FN) is the blend of structurally different molecules (isoforms) whose makeup varies depending on the FN sources. Fibronectin polymorphism is caused by three sequences (called ED-A, ED-B, and IIICS) which may be included or excluded from the FN molecule depending on the alternative splicing patterns of a single primary transcript. The sequence ED-B, which is a complete type III repeat of 91 amino acids, presents some interesting peculiarities: it is the most conserved FN region and, in normal adult tissues, the ED-B-containing FN has an extremely restricted distribution while having a much greater expression in fetal and tumor tissues (Carnemolla et al., 1989, J. Cell Biol. 108, 1139-1148), suggesting that the ED-B sequence may confer to the FN molecules specific biological activities required during ontogenesis and oncogenetic processes. Here we describe a detailed procedure to purify fibronectin fragments containing the ED-B sequence. These purified fragments are useful reagents in the study of the biological function(s) of the ED-B-containing FN molecules.
纤连蛋白（FN）是由结构不同的分子（同种型）混合而成，其组成因FN来源而异。纤连蛋白多态性由三个序列（称为ED - A、ED - B和IIICS）引起，根据单个初级转录本的可变剪接模式，这些序列可能包含在FN分子中或从FN分子中排除。序列ED - B是一个由91个氨基酸组成的完整III型重复序列，具有一些有趣的特性：它是FN中最保守的区域，在正常成人组织中，含ED - B的FN分布极为有限，而在胎儿和肿瘤组织中表达则高得多（Carnemolla等人，1989年，《细胞生物学杂志》108卷，1139 - 1148页），这表明ED - B序列可能赋予FN分子在个体发育和肿瘤发生过程中所需的特定生物学活性。在此，我们描述了一种纯化含有ED - B序列的纤连蛋白片段的详细方法。这些纯化片段是研究含ED - B的FN分子生物学功能的有用试剂。
