110 III. OXIDATION AND METABOLISM 



boxyl groups, as in the case of the dicarboxyhc acids, adipic, glutaric, pi- 

 melic, and azelaic, the fatty acid oxidase has been found to be inert. ^°^ 



In addition to liver preparations, which yield a potent fatty acid oxi- 

 dase, '^^~^^^ in the presence of ATPj^"^ kidney tissue and heart muscle ^^^ serve 

 as satisfactory sources of the enzyme. In the latter two tissues, the oxida- 

 tion proceeds via the tricarboxylic acid cycle, and acetoacetate does not ac- 

 cumulate. ^'^^^ The presence of fatty acid oxidase in shces of lung, spleen, 

 brain, heart, and skeletal muscle has been demonstrated by Geyer et al."^ 

 Lung and spleen are especially active.' Fatty acid oxidase preparations of 

 the Uver mitochondria in isotonic sucrose were reported to be relatively 

 stable to freezing and storage at a low temperature.'^ 



b. Lipoxidase. (a) Introduction. Lipoxidase is an enzyme active pri- 

 marily in the oxidation of the polyethenoid acids. For a number of years, 

 it was erroneously considered to be a carotene oxidase. Thus, Haas and 

 Bohn^^" demonstrated that pigments could be bleached by an enzyme pres- 

 ent in soybeans. The enzyme was shown to destroy vitamin A activity 

 completely. '^^ Moreover, a similar phenomenon was brought about by the 

 enzymes in alfalfa, ^^^'^*' which were later found to be lipoxidases.^^^'^^^ 



Andre and Hou,'^^ in 1932, were the first to discover the fat-oxidizing en- 

 zyme in soybeans {Glycine soja), and to propose the name "lipoxidase." 

 Apparently this is the same enzyme which had previously been referred to 

 as "carotene oxidase." Four years later, Craig^^^ reported a similar en- 

 zyme system in white lupine (Lupinus albus L.). It was shown by Sumner 

 and Dounce^*^ that the production of peroxides occurred concomitantly 

 with the action of carotene oxidase. Somewhat later, it was reported ^^''^^° 

 that carotene oxidase bleaches carotene only if fat is present. Although 

 Tauber^^" believed that carotene was oxidized by the peroxide formed by the 

 oxidation of unsaturated acids ("unsaturated fat oxidase"), Sumner'^' 



™ A. Lehninger, /. Biol. Chem., 165, 131-145 (1946). 



"3 R. p. Geyer, L. W. Matthews, and F. J. Stare, /. Biol. Chem., 180, 1037-1045 

 (1950). 



180 L. W. Haas and R. M. Bohn, U. S. Patents Nos. 1,957,333 to 1,957,337 (May 1, 

 1934). 



1" C. N. Frey, A. S. Schultz, and R. F. Light, Ind. Eng. Chem., 28, 1254 (1936). 



182 S. M. Hauge and W. Aitkenhead, /. Biol. Chem., 93, 657-665 (1931). 



183 S. M. Hauge, J. Biol. Chem., 108, 331-336 (1935). 



184 H. L. Mitchell and S. M. Hauge, /. Biol. Chem., 163, 7-14 (1946). 

 186 H. L. Mitchell and H. H. King, J. Biol. Chem., 166, 477-480 (1946). 



186 E. Andre and K. Hou, Compt. rend., 194, 645-647 (1932); 195, 172-174 (1932). 



187 F. N. Craig, J. Biol. Chem., 114, 727-746 (1936). 



188 J. B. Sumner and A. L. Bounce, Enzymologia, 7, 130-132 (1939). 



189 J. B. Sumner and R. J. Sumner, /. Biol. Chem., 134, 531-533 (1940). 

 "0 H. Tauber, /. Am. Chem. Soc, 62, 2251 (1940). 



"1 R. J. Sumner, /. Biol. Chem., 146, 215-218 (1942). 



