IMMUNOCHEMICAL STRUCTURE OF THE CARBOXY-TERMINAL PART OF HEPATITIS-B E-ANTIGEN - IDENTIFICATION OF INTERNAL AND SURFACE-EXPOSED SEQUENCES
IMMUNOCHEMICAL STRUCTURE OF THE CARBOXY-TERMINAL PART OF HEPATITIS-B E-ANTIGEN - IDENTIFICATION OF INTERNAL AND SURFACE-EXPOSED SEQUENCES
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DOI：
10.1099/0022-1317-74-7-1335
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发表时间：
1993-07-01
影响因子：
3.8
通讯作者：
MAGNIUS, LO
中科院分区：
文献类型：
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作者：
SALLBERG, M;PUSHKO, P;MAGNIUS, LO
研究了乙型肝炎病毒（HBV） e抗原（HBeAg） c端氨基酸（aa） 121 ~ 147，与15种单克隆抗体（mab）和16例慢性携带者血清对HB表面抗原具有抗hbe的反应性。将HBc/e多肽片段（aa 29 ~ 176、60 ~ 176、101 ~ 176、121 ~ 176、134 ~ 176、138 ~ 176、139 ~ 176、140 ~ 176、146 ~ 176和156 ~ 176）融合到RNA噬菌体外壳蛋白的N端，构建了重组蛋白，同时构建了覆盖残基121 ~ 136和130 ~ 147的两组合成肽，其中每个残基依次被丙氨酸取代。发现单克隆抗体识别融合蛋白残基121 ~ 176的重叠表位；然而，单克隆抗体没有与覆盖残基146 ~ 176和156 ~ 176的蛋白发生反应。利用合成的多肽，发现单克隆抗体识别128-TPPAYR-133、133-RPPNAP-138、135-PNAPIL-140、138-PILSTLPE-145和143-LPET-146残基的表位。发现只有识别表位128-TPPAYR-133的单抗能与天然HBeAg和变性HBcAG发生反应，而识别靠近HBeAg C端表位的单抗只能与变性HBcAG发生反应。人类IgG1的识别位点与识别天然HBeAg的单克隆抗体的表位重叠。我们对这些发现的解释是，124至133区位于天然HBeAg和变性HBcAg的表面，而邻近的135至147区在天然HBeAg表面无法进入，但在变性HBcAg上暴露。
The C-terminal region of hepatitis B virus (HBV) e antigen (HBeAg), amino acids (aa) 121 to 147, was characterized for reactivity with 15 monoclonal antibodies (MAbs) and sera from 16 chronic carriers on the HB surface antigen with anti-HBe. Recombinant proteins exposing fragments of the HBc/e polypeptide (aa 29 to 176, 60 to 176, 101 to 176, 121 to 176, 134 to 176, 138 to 176, 139 to 176, 140 to 176, 146 to 176 and 156 to 176) fused to the N terminus of the coat protein of RNA phage fr were constructed, as were two sets of synthetic peptides covering residues 121 to 136 and 130 to 147, where each residue was sequentially substituted by alanine. The MAbs were found to recognize overlapping epitopes in the fusion proteins within residues 121 to 176; however, none of the MAbs reacted with proteins covering residues 146 to 176 and 156 to 176. Using the synthetic peptides it was found that the MAbs recognized epitopes at residues 128-TPPAYR-133, 133-RPPNAP-138, 135-PNAPIL-140, 138-PILSTLPE-145 and 143-LPET-146. Only MAbs recognizing the epitope 128-TPPAYR-133 were found to react with both native HBeAg and denatured HBcAG, whereas MAbs recognizing epitopes located closer to the C terminus of HBeAg were reactive only with denatured HBcAg. The recognition sites for the human IgG1 overlapped with the epitopes of the MAbs recognizing native HBeAg. Our interpretation of these findings is that the region 124 to 133 is on the surface of native HBeAg and denatured HBcAg, and that the adjacent region 135 to 147 is not accessible on the surface of native HBeAg, but becomes exposed on denatured HBcAg.