Green hemoprotein of erythrocytes: methemoglobin superoxide transferase

Journal Article · Fri Jan 01 04:00:00 EST 1988 · Physiol. Chem. Phys. Med. NMR; (United States)

OSTI ID:6460452

Kiel, J L; McQueen, C; Erwin, D N

Influences of base (pH 10), heat (50 degrees C), microwave radiation (2450 MHz, 103 +/- 4 W/kg), and hydrogen peroxide (5.6 mM) generated by glucose oxidase on oxidation of human oxyhemoglobin to methemoglobin were examined. Conversion of oxyhemoglobin to methemoglobin was followed by the difference in absorbancy of 540 or 542 nm and 576 nm wavelength light versus time. Fresh basic hemolysates auto-oxidized on heating with a zero order rate constant, implying that hemoglobin or another protein saturated with oxyhemoglobin catalyzed the oxidation. Simultaneous microwave irradiation inhibited thermally induced auto-oxidation on the average by 28.6%. However, there was great variability among samples and a decrease in auto-oxidation with aging of individual samples. The auto-oxidation rate was independent of initial oxyhemoglobin concentration. Oxidation of partially purified oxyhemoglobin by hydrogen peroxide was not influenced by microwave irradiation. Adding green hemoprotein isolated from human erythrocytes to the oxyhemoglobin/glucose oxidase reaction mixture yielded absorption spectra (500-600 nm) that were a combination of oxyhemoglobin, deoxyhemoglobin, and methemoglobin spectra. Green hemoprotein was labile in hemolysates but stable in a partially purified ferric form. These results imply that thermally unstable reduced green hemoprotein can reverse oxidation of oxyhemoglobin by hydrogen peroxide and could mediate the thermally induced and microwave inhibited auto-oxidation of oxyhemoglobin.

• Research Organization: USAF School of Aerospace Medicine, Brooks AFB, TX (USA)
• OSTI ID: 6460452
• Journal Information: Physiol. Chem. Phys. Med. NMR; (United States), Journal Name: Physiol. Chem. Phys. Med. NMR; (United States) Vol. 20:2; ISSN PCPNE
• Country of Publication: United States
• Language: English

Related Subjects

560200 -- Thermal Effects
560300* -- Chemicals Metabolism & Toxicology
560400 -- Other Environmental Pollutant Effects
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ABSORPTION SPECTRA
BIOLOGICAL EFFECTS
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
ELECTROMAGNETIC RADIATION
ENERGY
ENZYMES
ERYTHROCYTES
GLOBIN
HEAT
HEMOGLOBIN
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HYDROGEN COMPOUNDS
HYDROGEN PEROXIDE
MATERIALS
METABOLISM
MICROWAVE RADIATION
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXIDOREDUCTASES
OXYGEN COMPOUNDS
PEROXIDES
PIGMENTS
PORPHYRINS
PROTEINS
RADIATIONS
REDOX REACTIONS
SPECTRA
TRANSFERASES