Some Controversial Aspects of the Mammalian Cytochromes

Newer Knowledge of Succinic Dehydrogenase

“…Isolation of the soluble dehydrogenase, as a matter of fact, offers considerable support for the less rigid concept, since the evidence indicates that it is not an altered or degraded enzyme, as has been suggested both by Green (21,108) and by Wainio and Cooperstein (10). It may be worth while, therefore, to consider briefly the characteristics of the enzyme from this point of view.…”

“…It is this difference which caused Wainio and Cooperstein to suggest that the enzyme may have been altered in its isolation (10). This difference is true, however, of a series of soluble preparations isolated by a multiplicity of techniques (extraction of acetone powders (29), of butanol-ether powders (34a), treatment of'wet material with n-butanol (38,44) sonic disintegration of cells (17)) from a vast array of starting materials.…”

“…By coupling the oxidation with the enzymic removal of fumarate to 11 noninhibitory product linearity may be maintained even longer (25,M). The second point, i.e., prevention of a lag period, is readily accomplished by equilibrating at 25 to 38" with phosphate or succinate for [8][9][10] minutes. When the assay i R carried out at a lower temperature, prior incubation of the dilute enzyme in phosphate buffer at or above 25" abolishes the lag period.…”