Esen A
Department of Biology, Virginia Polytechnic Institute and State University, Blacksburg 24061.
J Protein Chem. 1990 Aug;9(4):453-60. doi: 10.1007/BF01024621.
The immunochemical data from studies with polyclonal antisera to gamma-zein1, the 27 kD component of the maize prolamin, indicated that the region containing 8 tandem repeats of the sequence PPPVHL is an immunodominant site. In one case, the entire antibody repertoire of an antiserum recognized epitope(s) within this region. Three 17-mer oligopeptides corresponding to the predicted antigenic epitopes of gamma-zein1 were synthesized and reacted with three different anti-gamma-zein1 sera in order to map antigenic sites in the intact protein. These antisera yielded positive reactions with a 17-mer peptide (peptide 37), which was not in a hydrophilic maximum but derived from the repeat region. The same antisera gave little or no reaction with other peptides (peptides 38 and 39), both of which were in a hydrophilic maximum. In addition, an antiserum to peptide 37 reacted strongly with both the homologous antigen and the intact gamma-zein1. Peptide 37 also blocked the binding of antisera to gamma-zein1 in competition assays. Subsequently, the shorter 6-mer (peptide 82) and 12-mer (peptide 80) versions of peptide 37 were synthesized, and both reacted with anti-peptide 37 serum and also with each of the three anti-gamma-zein1 sera. In these reactions and in competition assays, the reactivity and the blocking ability increased in proportion to the length of the peptide. Based on these data, it was concluded that the repeat region of gamma-zein1 is the site of one or more continuous immunodominant epitopes. The data also suggest that the repeat region is exposed on the surface of the folded protein and probably occur as a mobile, random coil.
针对玉米醇溶蛋白27kD组分γ-醇溶蛋白1的多克隆抗血清的研究所得免疫化学数据表明，含有序列PPPVHL的8个串联重复的区域是一个免疫显性位点。在一个实例中，抗血清的整个抗体库识别该区域内的表位。合成了对应于γ-醇溶蛋白1预测抗原表位的三种17聚体寡肽，并使其与三种不同的抗γ-醇溶蛋白1血清反应，以便绘制完整蛋白中的抗原位点。这些抗血清与一种17聚体肽（肽37）产生阳性反应，该肽不在亲水性最大值处，而是源自重复区域。相同的抗血清与其他两种肽（肽38和39）几乎没有反应或无反应，这两种肽均处于亲水性最大值处。此外，针对肽37的抗血清与同源抗原和完整的γ-醇溶蛋白1均发生强烈反应。在竞争试验中，肽37也阻断抗血清与γ-醇溶蛋白1的结合。随后，合成了肽37的较短的6聚体（肽82）和12聚体（肽80）变体，二者均与抗肽37血清以及三种抗γ-醇溶蛋白1血清中的每一种发生反应。在这些反应和竞争试验中，反应性和阻断能力与肽的长度成比例增加。基于这些数据，得出结论：γ-醇溶蛋白1的重复区域是一个或多个连续免疫显性表位的位点。数据还表明，重复区域暴露于折叠蛋白的表面，可能以移动的无规卷曲形式存在。
