Enzymatic reduction of hemoglobins M Milwaukee-1 and M Saskatoon by NADH-cytochrome b5 reductase and NADPH-flavin reductase purified from human erythrocytes.

Abstract

Enzymatic reduction of the hemoglobin (Hb) M group was studied. Hb M Milwaukee-1 and Hb M Saskatoon were reduced by NADH-cytochrome b5 reductase highly purified from human erythrocytes. Hb M Saskatoon was also reduced by another enzyme in red cells, NADPH-flavin reductase. The reduction rates of Hb M Saskatoon by both enzymes were almost the same as those of MetHb A. The reduction of Hb M Milwaukee-1 by NADH-cytochrome b5 reductase progressed much more slowly than that of Hb M Saskatoon and MetHb A. It took 1/2 h and 10 h for the 50% reduction of Hb M Saskatoon and Hb M Milwaukee-1, respectively. These two methemoglobin reductases from erythrocytes did not reduce other hemoglobins M such as Hb M Iwate, Hb M Boston, or Hb M Hyde Park. A possible role of these abnormal hemoglobins as oxygen carriers and the reason for cyanosis in the patients of Hb M Saskatoon and Hb M Milwaukee-1 are discussed.

• Authors: M Nagai, T Yubisui, Y Yoneyama
• Journal: The Journal of biological chemistry (J Biol Chem) Vol. 255 Issue 10 Pg. 4599-602 (May 25 1980) ISSN: 0021-9258 [Print] United States
• PMID: 7372598 (Publication Type: Comparative Study, Journal Article)

Chemical References

• Flavins
• Hemoglobins, Abnormal
• Hemoglobin A
• FMN Reductase
• NADH, NADPH Oxidoreductases
• Cytochrome Reductases
• Cytochrome-B(5) Reductase

Topics

• Cytochrome Reductases (blood)
• Cytochrome-B(5) Reductase
• Erythrocytes (enzymology)
• FMN Reductase
• Flavins (blood)
• Hemoglobin A
• Hemoglobins, Abnormal
• Humans
• Kinetics
• NADH, NADPH Oxidoreductases (blood)
• Oxidation-Reduction
• Spectrophotometry