Ashton-Rickardt P G, Murray K
Department of Molecular Biology, University of Edinburgh, Scotland.
J Med Virol. 1989 Nov;29(3):196-203. doi: 10.1002/jmv.1890290310.
The nature of the immunodominant a region of hepatitis B virus surface antigen (HBsAg) has been examined by mutation of specific amino acid residues. Proline 142 was required for the exhibition of full antigenicity. Replacement of cysteines 124 and 147 by serines drastically reduced or eliminated reactivity with antibodies to HBsAg, which implicates these two residues in stabilising the conformation of the antigen. The a region of HBsAg has also been shown to influence both the immunoreactivity of the adjacent subtype antigenic region, despite being immunologically distinct from it, and the ability of the antigen to interact with a subtype-specific monoclonal antibody. These results emphasise the importance of the polypeptide region between cysteine residues 124 and 147 in determining a antigenicity, as well as manifestation of the subtype of HBsAg, and reinforce the view that these are conformational epitopes.
通过特定氨基酸残基的突变，对乙型肝炎病毒表面抗原（HBsAg）免疫显性a区的性质进行了研究。脯氨酸142是展现完全抗原性所必需的。用丝氨酸取代半胱氨酸124和147会大幅降低或消除与抗HBsAg抗体的反应性，这表明这两个残基在稳定抗原构象中起作用。HBsAg的a区还被证明，尽管在免疫上与相邻的亚型抗原区不同，但会影响其免疫反应性以及抗原与亚型特异性单克隆抗体相互作用的能力。这些结果强调了半胱氨酸残基124和147之间的多肽区域在决定a抗原性以及HBsAg亚型表现方面的重要性，并强化了这些是构象表位的观点。
