REACTIONS OF CYTOCHROME OXIDASE

Reactions of cytochrome oxidase.

In 1939 Keilin and Hartree (2) advanced the concept that there are two cytochrome components reacting between cytochrome c and oxygen; namely, cytochrome a and cytochrome a3. They based their hypothesis principally on the action of carbon monoxide which caused the a-band of reduced cytochrome a to spread toward 590 rnp and the r-band at 448 rnp to shift to 430 rnp and to be replaced by a very p...

Reactions of oxygenated cytochrome oxidase.

Reactions of cytochrome oxidase with oxygen and carbon monoxide.

Although spectrophotometric determinations of steady states together with turnover rates have allowed Chance (1952) to calculate that the rate of reaction of reduced cytochrome oxidase with oxygen must be about 107M-1 sec.-', no direct measurements of this rate appear to have been reported. This is due to the difficulty of obtaining the enzyme in a form which can be studied spectrophotometrical...

Coupled proton and electron transfer reactions in cytochrome oxidase.

Cytochrome oxidase catalyzes the four-electron reduction of O2 to water and conserves the substantial free energy of the reaction in the form of a protonmotive force. For each electron, two full charges are translocated across the membrane, resulting in a voltage. One of the mechanisms to generate the charge separation in cytochrome oxidase is via a proton pump. A single reaction cycle can be m...

Cytochrome oxidase of cactus.

The present autlhors have isolated a particleassociated cytochrome oxidase from the phylloclades of cactus plant and studied its kinetics. To our knowledge, this is the first report on cytoclhrome oxidase from a crassulacean plant. Tender phylloclades of Nopalea dejecta SalmDyck were ground with 5 volumes of chilled medium in a Waring Blendor operated first at low speed for 25 seconds and then ...