Parker K C, Bednarek M A, Hull L K, Utz U, Cunningham B, Zweerink H J, Biddison W E, Coligan J E
Biological Resources Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892.
J Immunol. 1992 Dec 1;149(11):3580-7.
Previous studies have indicated that most HLA-A2-binding peptides are 9 amino acid (aa) residues long, with a Leu at position 2 (P2), and a Val or Leu at P9. We compared the binding properties of different peptides by measuring the rate of dissociation of beta 2-microglobulin from peptide-specific HLA-A2 complexes. The simplest peptide that we identified that could form HLA-A2 complexes had the sequence (in single letter aa code) GLFGGGGGV, indicating that three nonglycine aa are sufficient for binding to HLA-A2. To determine whether most nonapeptides that contained Leu at P2 and Val or Leu at P9 could bind to HLA-A2, we tested the binding of nonapeptides selected from published HIV and melanoma protein sequences, and found that six of seven tested formed stable HLA-A2 complexes. We identified an optimal antigenic undecapeptide from the cytomegalovirus gB protein that could form stable HLA-A2 complexes that contained apparent anchor residues at P2 and P11 (sequence FIAGN-SAYEYV), indicating that the spacing between anchor residues can be somewhat variable. Finally, we tested the importance of every aa in the influenza A matrix peptide 58-66 (sequence GILGFVFTL) for binding to HLA-A2, by using Ala-substituted and Lys-substituted peptides. We found that multiple positions were important for stable binding, including P2, P3, P5-P7, and P9. We conclude that the P2 and P9 anchor residues are of prime importance for peptide binding to HLA-A2. However, other peptide side chains (especially at P3) contribute to the stability of the interaction. In certain cases, the optimal length for peptide binding can be longer than 9 residues.
先前的研究表明，大多数与HLA - A2结合的肽段长度为9个氨基酸（aa）残基，在第2位（P2）为亮氨酸（Leu），在P9位为缬氨酸（Val）或亮氨酸。我们通过测量β2 - 微球蛋白从肽特异性HLA - A2复合物上解离的速率，比较了不同肽段的结合特性。我们鉴定出的能够形成HLA - A2复合物的最简单肽段序列为（单字母氨基酸编码）GLFGGGGGV，这表明三个非甘氨酸氨基酸对于与HLA - A2结合就足够了。为了确定大多数在P2位含亮氨酸且在P9位含缬氨酸或亮氨酸的九肽是否能与HLA - A2结合，我们测试了从已发表的HIV和黑色素瘤蛋白序列中选取的九肽的结合情况，发现七个测试肽段中有六个形成了稳定的HLA - A2复合物。我们从巨细胞病毒gB蛋白中鉴定出一种最佳抗原性十一肽，它能形成稳定的HLA - A2复合物，在P2和P11位含有明显的锚定残基（序列FIAGN - SAYEYV），这表明锚定残基之间的间距可以有一定变化。最后，我们通过使用丙氨酸取代和赖氨酸取代的肽段，测试了甲型流感病毒基质肽58 - 66（序列GILGFVFTL）中每个氨基酸对于与HLA - A2结合的重要性。我们发现多个位置对于稳定结合都很重要，包括P2、P3、P5 - P7和P9。我们得出结论，P2和P9锚定残基对于肽段与HLA - A2的结合至关重要。然而，其他肽段侧链（尤其是在P3位）有助于相互作用的稳定性。在某些情况下，肽段结合的最佳长度可能超过9个残基。
