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Hemichrome formation observed in human haemoglobin A under various buffer conditions
Y Sugawara1, E Kadono, A Suzuki
1Department of Health Science, Hiroshima Prefectural Women's University, Health Science, Hiroshima, Japan.
Acta Physiologica Scandinavica
|August 28, 2003
Summary
Hemichrome formation in human haemoglobin A (HbA) is influenced by pH, temperature, and autoxidation progress. This process, leading to precipitation, occurs at different stages and is crucial for blood circulation homeostasis.
Area of Science:
- Biochemistry
- Hematology
Background:
- Hemoglobin A (HbA) is the primary oxygen carrier in red blood cells.
- Understanding HbA degradation pathways is vital for blood homeostasis.
Purpose of the Study:
- To investigate hemichrome formation in human HbA.
- To determine the influence of buffer conditions, pH, and temperature on hemichrome formation.
Main Methods:
- Spectrophotometric analysis of human oxyhaemoglobin A (HbO2) autoxidation.
- Experiments conducted in 0.1 M buffer across a range of temperatures (35–55°C) and pH values (4.5–10.5).
Main Results:
- Hemichrome formation, leading to precipitation, was observed during HbO2 autoxidation.
- The stage of hemichrome formation (initial, intermediate, or final) depended on solution pH and temperature.
- Human HbO2 showed high susceptibility to hemichrome formation, a process influenced by pH, temperature, and autoxidation extent.
- Bovine myoglobin (MbO2) demonstrated lower propensity for hemichrome formation compared to HbO2.
Conclusions:
- Hemichrome formation is a dynamic process influenced by multiple factors.
- The study provides insights into the role of the hemoglobin molecule in processes like senescent cell recognition and blood circulation homeostasis.
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