Beeson C, McConnell H M
Department of Chemistry, Stanford University, CA 94305.
Proc Natl Acad Sci U S A. 1994 Sep 13;91(19):8842-5. doi: 10.1073/pnas.91.19.8842.
The kinetics of the reactions between fluorescently labeled sperm whale myoglobin-(110-121) peptide and the murine major histocompatibility complex class II protein I-Ed have been analyzed. The presence in solution of both short- and long-lived protein-peptide complexes is demonstrated by the biphasic dissociation of the myoglobin peptide from I-Ed. The formation of the long-lived terminal complex is preceded by a characteristic induction phase. It is shown that the initially formed complex of the myoglobin peptide and I-Ed is a kinetic intermediate that undergoes a unimolecular reaction to form the terminal complex. Reactions between peptides and the class II proteins thus involve an intermediate structurally distinct from the terminal complex. The terminal complex presumably has a structure that is biologically active and similar to the published class II protein-peptide crystal structure.
已对荧光标记的抹香鲸肌红蛋白-（110-121）肽与小鼠主要组织相容性复合体II类蛋白I-Ed之间反应的动力学进行了分析。肌红蛋白肽与I-Ed的双相解离证明了溶液中存在短寿命和长寿命的蛋白质-肽复合物。长寿命末端复合物的形成之前有一个特征性的诱导期。结果表明，肌红蛋白肽与I-Ed最初形成的复合物是一种动力学中间体，它会发生单分子反应形成末端复合物。因此，肽与II类蛋白之间的反应涉及一种结构与末端复合物不同的中间体。末端复合物可能具有生物活性结构，且与已发表的II类蛋白-肽晶体结构相似。
