Sugawara Y, Kadono E, Suzuki A, Yukuta Y, Shibasaki Y, Nishimura N, Kameyama Y, Hirota M, Ishida C, Higuchi N, Haramoto K, Sakai Y, Soda H
Department of Health Science, Hiroshima Prefectural Women's University, Health Science, Hiroshima, Japan.
Acta Physiol Scand. 2003 Sep;179(1):49-59. doi: 10.1046/j.1365-201X.2003.01142.x.
To observe hemichrome formation in human haemoglobin A under various buffer conditions.
Hemichrome formation of human oxyhaemoglobin A (HbO2) was studied spectrophotometrically in 0.1 m buffer at various temperatures and pH values.
Following autoxidation in ferrous HbO2, it was evident that formation of hemichrome, which tends to precipitate, occurred at various stages during the course of the autoxidation reaction namely at initial, intermediate or final stages, depending on temperature and pH of the solution. By varying temperature of the solution from 35 to 55 degrees C and pH from 4.5 to 10.5, it is shown here that HbO2 exhibits high susceptibility for hemichrome formation and its occurrence is a function of pH, temperature and progress of autoxidation of HbO2. Unlike HbO2 and its separated haemoglobin chains, monomeric bovine heart myoglobin (MbO2) did not easily form hemichrome.
These findings provide a clue on the crucial role of haemoglobin molecule for senescent cell recognition or homeostasis in the blood circulation.
观察在不同缓冲条件下人类血红蛋白A中高铁血红素的形成。
采用分光光度法研究人氧合血红蛋白A（HbO₂）在0.1m缓冲液中于不同温度和pH值下高铁血红素的形成。
亚铁HbO₂自氧化后，很明显高铁血红素的形成倾向于沉淀，在自氧化反应过程中的不同阶段即初始、中间或最终阶段发生，这取决于溶液的温度和pH值。通过将溶液温度从35℃变化到55℃以及pH值从4.5变化到10.5，结果表明HbO₂对高铁血红素的形成表现出高度敏感性，其出现是pH值、温度以及HbO₂自氧化进程的函数。与HbO₂及其分离的血红蛋白链不同，单体牛心肌红蛋白（MbO₂）不容易形成高铁血红素。
这些发现为血红蛋白分子在血液循环中对衰老细胞识别或体内平衡的关键作用提供了线索。
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