Bhatnagar P K, Papas E, Blum H E, Milich D R, Nitecki D, Karels M J, Vyas G N
Proc Natl Acad Sci U S A. 1982 Jul;79(14):4400-4. doi: 10.1073/pnas.79.14.4400.
Recovery from a natural infection with hepatitis B virus or vaccination with purified envelope protein leads to production of antibodies against the hepatitis B surface antigen (HBsAg). Such physiologic response in man is generally directed against the a determinant of HBsAg common to all serotypes of the virus. To define the immunochemical specificity of this determinant, the secondary structure of HBsAg was derived from its sequence of 226 amino acids. Hydrophilic stretches expected to contain the antigenic determinants were located between residues 32 and 76 and between residues 110 and 156. Loss of the antigenic activity after chemical modification of lysine residues of HBsAg indicated their critical importance in antigenicity. Because all lysines are located between residues 121 and 160, we selected this region for localization of HbsAg determinants. Solid-phase synthesis was used to prepare seven peptide analogues of HBsAg (PsAs): 122-137, 128-134, 139-147, 139-158, 140-158, 145-158, and 150-158. For experimental immunization of rabbits the synthetic peptides were coupled to keyhole limpet hemocyanin. We studied the antigenicity of each peptide analogue by serologic neutralization of human antibodies specific for the a determinant of HBsAg. Analogues 139-147, 139-158, and 140-158 showed antigenicity as well as function of anti-HBsAg. The rabbit antibodies were inhibited with each of the three peptide analogues and all serotypes of natural HbSag, having only the a determinant in common. These results indicate that the nonapeptide sequence 139-147 represents the total or an essential part of the a determinant of HBsAg.
从乙肝病毒自然感染中恢复或用纯化包膜蛋白进行疫苗接种会导致产生针对乙肝表面抗原（HBsAg）的抗体。人类的这种生理反应通常针对该病毒所有血清型共有的HBsAg a决定簇。为了确定该决定簇的免疫化学特异性，根据其226个氨基酸的序列推导了HBsAg的二级结构。预期包含抗原决定簇的亲水区位于32至76位氨基酸残基之间以及110至156位氨基酸残基之间。HBsAg赖氨酸残基经化学修饰后抗原活性丧失，表明它们在抗原性方面至关重要。由于所有赖氨酸都位于121至160位氨基酸残基之间，我们选择该区域来定位HBsAg决定簇。采用固相合成法制备了7种HBsAg肽类似物（PsAs）：122 - 137、128 - 134、139 - 147、139 - 158、140 - 158、145 - 158和150 - 158。为对兔子进行实验性免疫，将合成肽与钥孔戚血蓝蛋白偶联。我们通过对针对HBsAg a决定簇的人抗体进行血清学中和来研究每种肽类似物的抗原性。139 - 147、139 - 158和140 - 158这几种类似物表现出抗原性以及抗HBsAg功能。兔抗体被这三种肽类似物以及仅具有共同a决定簇的所有天然HBsAg血清型所抑制。这些结果表明，九肽序列139 - 147代表了HBsAg a决定簇的全部或重要部分。
