Spectral analysis of Fe(III)-complex reduction by hemoglobin: possible mechanisms of interaction.
1. Hemoglobin is capable of electron transfer to Fe(III)-complexes of ATP, EDTA, NTA, and citrate leading to formation of reduced Fe(II) and its concurrent release from these chelating compounds as evident in the formation of a Fe(II)-Tris 2,2' bipyridine complex. 2. Multi-component analysis of kinetic spectra in the visible region (700-500 nm) has permitted a determination of the effect of various chelating molecules bound to Fe(III), pH, the effects of ionic strength, temperature, and the molecular nature of the Fe(III)-complex on reaction rates. 3. We have examined and compared the reactivities of normal adult hemoglobin A (alpha 2 beta 2) to reduce these Fe(III)-complexes and suggest possible mechanism(s) for the electron transfer process.
Harrington
J P
JP
Department of Chemistry, University of South Alabama, Mobile 36688.
Hicks
R L
RL
D015082:2,2'-Dipyridyl / Q000737:chemistry / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000737:chemistry* / Q000378:metabolism; D000328:Adult; D001667:Binding, Competitive; D004492:Edetic Acid / Q000737:chemistry* / Q000378:metabolism; D004579:Electron Transport; D005290:Ferric Compounds / Q000737:chemistry* / Q000378:metabolism; D005296:Ferrous Compounds / Q000737:chemistry / Q000378:metabolism; D006441:Hemoglobin A / Q000737:chemistry / Q000378:metabolism*; D006454:Hemoglobins / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007502:Iron Chelating Agents / Q000737:chemistry / Q000378:metabolism; D007700:Kinetics; D008706:Methemoglobin / Q000096:biosynthesis; D009571:Nitrilotriacetic Acid / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D009994:Osmolar Concentration; D010084:Oxidation-Reduction; D013057:Spectrum Analysis; D013696:Temperature
D005290:Ferric Compounds; D005296:Ferrous Compounds; D006454:Hemoglobins; D007502:Iron Chelating Agents; D015082:2,2'-Dipyridyl; C025314:ferric citrate; D000255:Adenosine Triphosphate; C100003:deoxyhemoglobin; D008706:Methemoglobin; D006441:Hemoglobin A; C045858:ferric-adenosine triphosphate complex; D004492:Edetic Acid; D009571:Nitrilotriacetic Acid; C019179:Fe(III)-EDTA; C020326:ferric nitrilotriacetate