Affinity purification of antibodies using antigens immobilized on solid supports.
Affinity purification of antibodies using antigens immobilized on solid supports.
复制标题
使用固定在固体支持物上的抗原对抗体进行亲和纯化。
DOI:
10.1042/bst0160134
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发表时间:
1988
影响因子:
3.9
通讯作者:
Smith,DE
中科院分区:
文献类型:
--
作者:
Fisher,PA;Smith,DE
Olmsted (198 1) first reported a method for affinity purification of antibodies by binding them to their respective antigens that had been immobilized on diazotized paper blots following transfer from SDS/polyacrylamide gels. We have adapted her method to take advantage of nitrocellulose as a solid support and used it to replace diazotized paper, and have explored the potential for direct visualization of reactive primary antibodies using colorimetric detection of a secondary antibody coupled to calf alkaline phosphatase. The results of these studies have previously been published (Smith & Fisher, 1984). We have also investigated the suitability of cyanogen bromide (CNBr)-activated Sepharose as a solid support to replace nitrocellulose for large-scale immunoaffinity purification. The basic methodology for affinity purification of antibodies using polypeptides immobilized on nitrocellulose following SDS/polyacrylamide gel electrophoresis (PAGE) has been described in detail and will only be reviewed briefly. SDS/PAGE is performed essentially according to Laemmli (1970) with minor modifications (Fisher et al., 1982). After electrophoresis, proteins are blot-transferred from the gel to nitrocellulose passively. We find that passive transfer procedures, while relatively time consuming, result in consistently higher quality blots for analytical as well as preparative purposes. Electrophoretic transfer may nevertheless be used without serious adverse consequences. When gradient polyacrylamide gels are used, passive transfer is uniform throughout the range of polypeptide size (Fisher et al., 1982); on continuous concentration gels, transfer efficiency improves with decreasing mass. At worst, proteins larger than 200 kDa require 48-72 h for about 50% transfer. However, not all proteins behave identically. Some large proteins seem to transfer more efficiently, perhaps relating to their solubility in the particular transfer buffer used. In addition to what we feel is the superior technical quality of the resulting immunoblots, passive transfer is also preferred for affinity purification purposes for the following reason. The buffer that we use for blot-transfer includes 75 mM-Tris base and 570 mM-glycine and contains neither SDS nor methanol. We presume that at the outset, the proteins in the gel are fully complexed with SDS. The first ligand molecules delivered to the nitrocellulose are therefore in a denatured conformation. As transfer proceeds, the SDS is washed out of the gel and proteins theoretically have the opportunity to renature, at least partially. Ligands transferred late in the process may assume more native conformations on the nitrocellulose, thus allowing a broad representation of antigenic determinants on the solid support. Antibodies against a number of different polypeptide antigens have been affinity purified in our laboratory using