The activity of succinate oxidase in relation to phosphate and phosphorus compounds.

The usual procedure for the preparation of succinate oxidase involves the extraction of washed heart muscle with a mildly alkaline phosphate solution. A turbid dispersion is thus obtained which is resistant to precipitation by a low centrifugal force and which contains at least cytochrome oxidase, cytochromes a, 5, c, and a flavoprotein. This enzyme preparation, besides catalyzing the oxidation of succinate and p-phenylenediamine, can also be shown to be capable of gearing a pyridine nucleotide enzyme system to oxygen. It thus contains a major portion of the enzymes involved in the transfer of electrons and hydrogen ions from substrates to oxygen. In order to study the composition of this integrated enzyme complex and the possible formation of high energy phosphate compounds during its functioning, it seemed worth while to attempt its preparation by a procedure which did not involve the use of phosphate solutions. We describe here such a procedure along with some interesting properties of the resulting enzyme preparation.