Studies on the Oxidation-Reduction Potentials of Heme Proteins. IV. The Kinetics of Oxidation of Hemoglobin and Myoglobin by Ferricyanide*

Biochemistry ◽  
1965 ◽  
Vol 4 (3) ◽  
pp. 545-551 ◽  
Author(s):  
Eraldo Antonini ◽  
Maurizio Brunori ◽  
Jeffries Wyman
Keyword(s):  
Heme Proteins ◽  
Kinetics Of Oxidation ◽  
Reduction Potentials ◽  
Oxidation Reduction ◽  
Kinetics Of

scholarly journals Studies on the Oxidation-Reduction Potentials of Heme Proteins

1965 ◽  
Vol 240 (8) ◽  
pp. 3317-3324
Author(s):  
Maurizio Brunori ◽  
Jeffries Wyman ◽  
Eraldo Antonini ◽  
Alessandro Rossi-Fanelli
Keyword(s):  
Heme Proteins ◽  
Reduction Potentials ◽  
Oxidation Reduction

The Effects of Bicarbonate Depletion and Formate Incubation on the Kinetics of Oxidation-Reduction Reactions of the Photosystem II Quinone Acceptor Complex

1984 ◽  
Vol 39 (5) ◽  
pp. 382-385 ◽  
Author(s):  
Howard H. Robinson ◽  
Julian J. Eaton-Rye ◽  
Jack J. S. van Rensen ◽  
Keyword(s):  
Photosystem Ii ◽  
Redox State ◽  
Oxygen Electrode ◽  
Thylakoid Membranes ◽  
Acceptor Site ◽  
Kinetics Of Oxidation ◽  
Oxidation Reduction ◽  
Primary Quinone Acceptor ◽  
Quinone Acceptor ◽  
Kinetics Of

Chloroplast thylakoid membranes depleted of bicarbonate exhibit a slowed oxidation of the primary quinone acceptor (Qᴀ) by the secondary quinone acceptor (Qв) of photosystem II. The kinetics of these slowed reactions have been followed by using short xenon flashes of light both to excite photosystem II and to probe the redox state of Qᴀ. Thylakoids incubated with formate but not depleted of bicarbonate showed the same pattern of slowed reaction kinetics of the quinone acceptors as seen in bicarbonate-depleted| thylakoids. This led us to conclude that there was a simple competition between bicarbonate and formate at this site; however, steady-state electron transfer measured with an oxygen electrode showed that although the bicarbonate- depleted thylakoids were indeed inhibited, rates in the formate-incubated thylakoids were only slightly slowed. We suggest that the inhibition seen at the quinone acceptor site of photosystem II depends in a subtle way upon the rate of exchange of bicarbonate and formate at this site.

Concerning the form of biochemically active vanadium

1981 ◽  
Vol 212 (1186) ◽  
pp. 65-84 ◽  
Keyword(s):  
Transmembrane Potential ◽  
Tridentate Ligands ◽  
Vanadium Concentration ◽  
Hydrated Form ◽  
Reduction Processes ◽  
Reduction Potentials ◽  
Oxidation Reduction ◽  
Descriptive Chemistry ◽  
Kinetics Of ◽  
Vanadium Ions

A survey has been made of the descriptive chemistry of vanadium as it pertains to physiological environments. Taking into account the vanadium concentration, pH, coordinating ligands and chelates, presence of other cations, oxidation-reduction potentials and the kinetics of the various vanadium-containing species, the following suggestions are made. Free vanadium ions will be monomeric. Monomeric vanadium(V) and vanadium(IV) will each exist in a specific hydrated form. Extracellular vanadium will be in the vanadate, V v , form. Intracellular vanadium will most likely be predominately in the vanadyl, V IV , form. Both extracellular vanadium(V) and intracellular vanadium(IV) will be bound to bi- or tridentate ligands if at all. If oxidation-reduction processes involving vanadium are fast relative to transmembrane transport, the transmembrane potential will not be coupled to the V V / V IV Nernstian potential.

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