Tchernychev B, Rabinkov A, Miron T, Wilchek M
Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, Israel.
Immunol Lett. 2000 Jan 10;71(1):43-7. doi: 10.1016/s0165-2478(99)00162-5.
Human serum contains natural antibodies against alliinase, a protein abundantly found in garlic (Allium sativum) cloves. In order to study the epitope(s) of this protein recognized by anti-alliinase antibodies, we used a random hexapeptide library displayed on filamentous M13 phage. Analysis of the phagotopes selected on rabbit anti-alliinase antibodies revealed that the motif-GKXVXX- was common for all peptides. The most frequent phage displaying -GKHVAV- sequence has a 50% identity with the original alliinase sequence (amino acid residues 156-161). The position of this epitope is only nine amino acids apart from the oligosaccharide chain attached to the N146. The rabbit anti-alliinase immunoglobulin G (IgG), which bound the phages displaying this phagotope, also bound the corresponding peptide derived from the alliinase sequence. Affinity-purified natural antibodies against alliinase, present in normal human serum (which can specifically recognize the native and denaturated protein) also bound the selected phagotope. Thus, our results indicate that specific natural anti-dietary protein antibodies presented in human serum can have the same. or overlapping. epitopes with the IgG evoked during the active (experimental) immunization in animals.
人血清中含有针对蒜氨酸酶的天然抗体，蒜氨酸酶是一种在大蒜（蒜）蒜瓣中大量存在的蛋白质。为了研究抗蒜氨酸酶抗体识别的该蛋白质的表位，我们使用了展示在丝状M13噬菌体上的随机六肽文库。对在兔抗蒜氨酸酶抗体上选择的噬菌表位的分析表明，基序-GKXVXX-对所有肽来说都是常见的。展示-GKHVAV-序列的最常见噬菌体与原始蒜氨酸酶序列（氨基酸残基156 - 161）有50%的同一性。这个表位的位置与连接到N146的寡糖链仅相隔9个氨基酸。与展示这个噬菌表位的噬菌体结合的兔抗蒜氨酸酶免疫球蛋白G（IgG），也与源自蒜氨酸酶序列的相应肽结合。存在于正常人血清中的针对蒜氨酸酶的亲和纯化天然抗体（可特异性识别天然和变性蛋白质）也与所选噬菌表位结合。因此，我们的结果表明，人血清中存在的特异性天然抗膳食蛋白质抗体可具有与动物主动（实验性）免疫期间诱发的IgG相同或重叠的表位。
