Jezek P, Houstĕk J, Kotyk A, Drahota Z
Institute of Physiology, Czechoslovak Academy of Sciences, Prague.
Eur Biophys J. 1988;16(2):101-8. doi: 10.1007/BF00255519.
A hypothesis concerning two distinct classes of amino acid residues in some regulatory binding sites is proposed. The "affinity residues" are those that are unable to transduce the ligand information signal but are responsible for overcoming the barrier for the attachment of a ligand to its binding site while the "effector residues" transfer the binding signal to the other functional part of the protein, which then undergoes a non-equilibrium energetic cycle induced by interaction with the ligand. As an example, the purine nucleotide inhibition of H+ transport through the uncoupling protein of brown adipose tissue mitochondria is discussed; there is a concentration range in which the nucleotide is bound but does not inhibit H+ transport. This is interpreted in terms of inaccessibility of the effector residues inducing H+ transport inhibition below a certain threshold concentration.
提出了一个关于某些调节性结合位点中两类不同氨基酸残基的假说。“亲和残基”是那些无法传递配体信息信号，但负责克服配体附着于其结合位点的障碍的残基，而“效应残基”则将结合信号传递至蛋白质的其他功能部分，该部分随后会因与配体相互作用而经历一个非平衡能量循环。例如，讨论了嘌呤核苷酸对通过棕色脂肪组织线粒体解偶联蛋白的H⁺转运的抑制作用；存在一个核苷酸结合但不抑制H⁺转运的浓度范围。这是根据效应残基在低于特定阈值浓度时无法诱导H⁺转运抑制来解释的。
