Epitope Mapping of the Transforming Growth Factor- Superfamily Protein, Macrophage Inhibitory Cytokine-1 (MIC-1): Ide
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- 作者：W. Douglas Fairlie ; Patricia K. Russell ; Wan M. Wu ; Anthony G. Moore ; Hong-Ping Zhang ; Peter K. Brown ; Asne R. Bauskin ; and Samuel N. Breit
- 刊名：Biochemistry
- 出版年：2001
- 出版时间：January 9, 2001
- 年：2001
- 卷：40
- 期：1
- 页码：65 - 73
- 全文大小：568K
- 年卷期：v.40,no.1(January 9, 2001)
- ISSN：1520-4995
文摘
Macrophage inhibitory cytokine-1 (MIC-1) is a divergent member of the transforming growthfactor-
(TGF-) superfamily whose increased expression is associated with macrophage activation andwhich is expressed highly in placenta as compared to other tissues. There are two known allelic forms ofhuman MIC-1 due an amino acid substitution at position 6 of the mature protein. We have raised fourmonoclonal antibodies (MAbs) and one polyclonal antiserum to the mature protein region of human MIC-1and have used an extensive panel of MIC-1 relatives, mutants, and chimeras to map their epitopes. Noneof the MAbs were able to cross-react with either the murine homologue of MIC-1 or with hTGF-1, andall of the MAb epitopes were conformation-dependent. A distinct cross-reactivity pattern with the variousantigens was observed for each of the monoclonal and polyclonal antibodies suggesting the presence ofat least five immunogenic regions on the MIC-1 surface. One of the MAbs is directed against the aminoterminus of the protein and can distinguish between the two allelic forms of MIC-1. The epitopes for theother three MAbs were located near the tips of the so-called "fingers" of the protein and appeared to bepartially overlapping as each involved amino acids in the region 24-37. In one case, it was possible tomutate murine MIC-1 so that it could be recognized by one of the MAbs. Finally, the use of anothermutant in which Cys 77 was replaced by serine enabled confirmation of the location of the MIC-1 interchaindisulfide bond.
(TGF-) superfamily whose increased expression is associated with macrophage activation andwhich is expressed highly in placenta as compared to other tissues. There are two known allelic forms ofhuman MIC-1 due an amino acid substitution at position 6 of the mature protein. We have raised fourmonoclonal antibodies (MAbs) and one polyclonal antiserum to the mature protein region of human MIC-1and have used an extensive panel of MIC-1 relatives, mutants, and chimeras to map their epitopes. Noneof the MAbs were able to cross-react with either the murine homologue of MIC-1 or with hTGF-1, andall of the MAb epitopes were conformation-dependent. A distinct cross-reactivity pattern with the variousantigens was observed for each of the monoclonal and polyclonal antibodies suggesting the presence ofat least five immunogenic regions on the MIC-1 surface. One of the MAbs is directed against the aminoterminus of the protein and can distinguish between the two allelic forms of MIC-1. The epitopes for theother three MAbs were located near the tips of the so-called "fingers" of the protein and appeared to bepartially overlapping as each involved amino acids in the region 24-37. In one case, it was possible tomutate murine MIC-1 so that it could be recognized by one of the MAbs. Finally, the use of anothermutant in which Cys 77 was replaced by serine enabled confirmation of the location of the MIC-1 interchaindisulfide bond.