Karská K, Tucková L, Steiner L, Tlaskalová-Hogenová H, Michalak M
Department of Immunology and Gnotobiology, Czech Academy of Sciences, Prague.
Biochem Biophys Res Commun. 1995 Apr 17;209(2):597-605. doi: 10.1006/bbrc.1995.1542.
Monoclonal antibodies to gliadin were recently found to cross-react with epitopes on rat enterocytes. Two molecules of mol. mass 62 and 66 kDa were isolated from enterocyte lysates by affinity chromatography using antigliadin monoclonal antibodies. The N-terminal amino acid sequence of the 62-kDa protein was determined to be XXXIYFKEQFLD. This amino acid sequence corresponds to amino acid sequence of rat calreticulin. The presence of calreticulin in enterocyte lysates was further confirmed using anticalreticulin serum. Anticalreticulin serum was also used to investigate the reactivity of isolated rat calreticulin. To analyze whether gliadin and calreticulin share similar epitopes recognized by anticalreticulin antibodies, synthetic dodecapeptides derived from the amino acid sequence of alpha gliadin were used in competitive ELISA assay. Two gliadin peptides, QEQVPLVQQQQF and YQLLQELCCQHL, were found to inhibit the binding of rabbit anti-rat calreticulin sera to rat calreticulin. The significant correlation was detected between IgA anticalreticulin and antigliadin antibodies (r = 0.827; P < 0.001) in celiac patients.
最近发现，抗麦醇溶蛋白单克隆抗体与大鼠肠上皮细胞上的表位发生交叉反应。使用抗麦醇溶蛋白单克隆抗体通过亲和层析从肠上皮细胞裂解物中分离出分子量为62 kDa和66 kDa的两种分子。经测定，62 kDa蛋白的N端氨基酸序列为XXXIYFKEQFLD。该氨基酸序列与大鼠钙网蛋白的氨基酸序列一致。使用抗钙网蛋白血清进一步证实了肠上皮细胞裂解物中存在钙网蛋白。抗钙网蛋白血清还用于研究分离出的大鼠钙网蛋白的反应性。为了分析麦醇溶蛋白和钙网蛋白是否具有抗钙网蛋白抗体识别的相似表位，在竞争性ELISA试验中使用了源自α-麦醇溶蛋白氨基酸序列的合成十二肽。发现两种麦醇溶蛋白肽QEQVPLVQQQQF和YQLLQELCCQHL可抑制兔抗大鼠钙网蛋白血清与大鼠钙网蛋白的结合。在乳糜泻患者中，检测到抗钙网蛋白IgA与抗麦醇溶蛋白抗体之间存在显著相关性（r = 0.827；P < 0.001）。
