Pollack S, Weaver J
J Lab Clin Med. 1986 Nov;108(5):411-4.
In previous work we have shown that red cell hemolysates, at neutral pH, will release iron from transferrin; with molecular sieve chromatography, that activity separated into low molecular weight and high molecular weight components, both susceptible to destruction by phosphatases. Thus the possibility that nucleotides might be involved was suggested. We have studied the interaction of adenosine triphosphate (ATP) and an ammonium sulfate fraction of hemolysate with transferrin. ATP, as well as adenosine diphosphate and 2,3-diphosphoglyceric acid, interacts synergistically with the ammonium sulfate hemolysate fraction to promote iron release from transferrin. This activity is not limited to phosphorylated compounds, because citrate shows a similar effect. This activity is not a nonspecific chelating effect, because deferoxamine is without activity. All the synergistic anions labilize transferrin's HCO3. We therefore suggest that they form a non-HCO3 ternary complex with transferrin and iron, and that release of iron from this complex is promoted by a high molecular weight constituent of the hemolysate.
在之前的研究中我们发现，在中性pH条件下，红细胞溶血产物会促使转铁蛋白释放铁；通过分子筛层析法，该活性分离为低分子量和高分子量组分，二者均易被磷酸酶破坏。因此，有人提出核苷酸可能参与其中。我们研究了三磷酸腺苷（ATP）和溶血产物的硫酸铵组分与转铁蛋白的相互作用。ATP以及二磷酸腺苷和2,3-二磷酸甘油酸与硫酸铵溶血产物组分协同作用，促进转铁蛋白释放铁。这种活性并不局限于磷酸化化合物，因为柠檬酸盐也有类似作用。这种活性不是非特异性螯合作用，因为去铁胺没有活性。所有具有协同作用的阴离子都会使转铁蛋白的HCO3不稳定。因此我们认为，它们与转铁蛋白和铁形成了一种非HCO3三元复合物，并且溶血产物的高分子量成分会促进该复合物中铁的释放。
