ON QUESTION OF IDENTITY OF SOYBEAN LIPOXIDASE AND CAROTENE OXIDASE

It has been previously reported by Kies that controlled heating of a partially purified soybean lipoxidase causes the differential loss of its capacity to destroy carotene in the coupled reaction with methyl linoleate, but does not affect its capacity to promote the peroxidation of linoleic acid. The catalysis of the coupled reaction has long been ascribed to lipoxidase. It is now shown that the homogeneous crystalline preparation of soybean lipoxidase of Theorell and co-workers, which is effective against linoleic acid, is essentially ineffective in the above mentioned coupled reaction and is further resistant to the heat treatment employed. The catalysis of the coupled reaction must therefore be ascribed to a heat sensitive entity which is distinct from the Theorell lipoxidase. © 1969.