The free heme concentration in healthy human erythrocytes

摘要: Heme, the prosthetic group of hemoglobin, may be released from its host due to an intrinsic instability hemoglobin and accumulate in erythrocytes. Free heme is form hematin (Fe(3+) protoporphyrin IX OH) follows several pathways biochemical toxicity tissues, cells, organelles since it catalyzes production reactive oxygen species. To determine concentration soluble free human erythrocytes, we develop a new method. We lyse red blood cells isolate by dialysis. use reconstitute horseradish peroxidase (HRP) excess apoenzyme HRP reaction rate evolution emitted luminescence. find that population five healthy adults average erythrocytes 21±2μM, ca. 100× higher than previously determined. Tests suggest lower previous value was elevated concentrations NaCl, which drive precipitation re-association with apoglobin. show found significantly estimates based on equilibrium release known dimerization. The factors lead enhanced remain open question.