Buus S, Sette A, Colon S M, Jenis D M, Grey H M
Cell. 1986 Dec 26;47(6):1071-7. doi: 10.1016/0092-8674(86)90822-6.
Using equilibrium dialysis, it has been previously demonstrated that immunogenic peptides bind specifically to the Ia molecules serving as restriction elements in the immune response to these antigens. Using gel filtration to study the formation of ovalbumin (OVA) peptide-I-Ad complexes, it is herein demonstrated that the complexes, once formed, are very stable (kd approximately equal to 3 X 10(-6) s-1), but the rate of complex formation is very slow (ka approximately 1 M-1 s-1 explaining the overall low equilibrium constant of approximately 2 X 10(-6) M. Treating the complexes with glutaraldehyde revealed that the ovalbumin peptide was cross-linked solely to the alpha chain of I-Ad. Planar membranes containing I-Ad-OVA complexes stimulated a T cell response with 2 X 10(4) less antigen than required when uncomplexed antigen was used, thus demonstrating the biologic importance of these complexes in antigen recognition.
利用平衡透析法，先前已证明免疫原性肽能特异性结合Ia分子，这些Ia分子在针对这些抗原的免疫应答中作为限制元件。利用凝胶过滤法研究卵清蛋白（OVA）肽 - I - Ad复合物的形成，本文证明这些复合物一旦形成就非常稳定（解离常数kd约等于3×10⁻⁶ s⁻¹），但复合物形成的速率非常缓慢（结合常数ka约为1 M⁻¹ s⁻¹），这解释了总体较低的平衡常数约为2×10⁻⁶ M。用戊二醛处理这些复合物表明，卵清蛋白肽仅与I - Ad的α链交联。含有I - Ad - OVA复合物的平面膜刺激T细胞应答所需的抗原比使用未复合抗原时少2×10⁴ ，从而证明了这些复合物在抗原识别中的生物学重要性。
