Fruci D, Butler R H, Greco G, Rovero P, Pazmany L, Vigneti E, Tosi R, Tanigaki N
Istituto di Biologia Cellulare, CNR, Rome, Italy.
Immunogenetics. 1995;42(2):123-8. doi: 10.1007/BF00178586.
Two HLA-B27 subtypes, B2702 and B2705, both associated with ankylosing spondylitis, were tested for binding affinity with a panel of polyalanine model nonapeptides carrying Arg at position 2 (P2) and a series of different amino acids at position 9 (P9). The alpha chains were isolated from BTB(B2705), C1R/B2702 (a B2702 transfectant cell line) and from the NW (B2702) cell line that has a peculiar peptide presentation behavior. Peptide binding was measured by the HLA alpha chain refolding assay. The results obtained show that: 1) Peptides with basic residues (Arg and Lys) and also aliphatic (Leu) and aromatic (Phe and Tyr) peptides at P9 have a similar high affinity in the binding to B2705; 2) B2702 binds well to P9 aliphatic and aromatic peptides but only very weakly to P9 basic peptides. Since both B2702 and B2705 are associated with AS the presumed arthritogenic peptide is hypothesized to have an aromatic or aliphatic residue at position 9. Peptides with basic residues in this position would be excluded as candidates because of their low binding affinity with B*2702.
对两种均与强直性脊柱炎相关的HLA - B27亚型B2702和B2705，进行了与一组在第2位（P2）携带精氨酸（Arg）且在第9位（P9）带有一系列不同氨基酸的聚丙氨酸模型九肽的结合亲和力测试。α链分别从BTB（B2705）、C1R/B2702（一种B2702转染细胞系）以及具有独特肽呈递行为的NW（B2702）细胞系中分离得到。通过HLA α链重折叠测定法测量肽结合。所获得的结果表明：1）在P9位带有碱性残基（Arg和Lys）以及脂肪族（Leu）和芳香族（Phe和Tyr）的肽在与B2705的结合中具有相似的高亲和力；2）B2702与P9位脂肪族和芳香族肽结合良好，但与P9位碱性肽的结合非常弱。由于B2702和B2705均与强直性脊柱炎相关，因此推测致关节炎肽在第9位具有芳香族或脂肪族残基。该位置带有碱性残基的肽由于与B*2702的结合亲和力低而被排除在候选肽之外。
