Franzen S, Lambry J C, Bohn B, Poyart C, Martin J L
Laboratoire d'Optique Appliquée INSERM U275, Ecole Polytechnique-ENSTA, Palaiseau, France.
Nat Struct Biol. 1994 Apr;1(4):230-3. doi: 10.1038/nsb0494-230.
The study of cooperative ligand binding among the four subunits of haemoglobin has played a central role in the understanding of allosteric transitions in a large number of enzymes. Haem iron out-of-plane motion has been suggested to be the trigger for the cooperative transition of haemoglobin. To function as a trigger in a dynamic sense, haem-iron doming must be the first conformational change to occur following ligand dissociation. Here we present the first direct demonstration that haem-iron doming occurs on the same time scale as the breaking of the iron-ligand bond, thus establishing haem-iron doming as the primary event which lead to the R-->T transition in haemoglobin.
对血红蛋白四个亚基间协同配体结合的研究，在理解众多酶的别构转变过程中发挥了核心作用。有人提出血红素铁的平面外运动是血红蛋白协同转变的触发因素。要在动态意义上起到触发作用，血红素铁隆起必须是配体解离后发生的首个构象变化。在此，我们首次直接证明，血红素铁隆起与铁 - 配体键断裂发生在同一时间尺度上，从而确立了血红素铁隆起是导致血红蛋白从R态向T态转变的主要事件。
