OXIDATION OF NADPH BY SOLUBLE FRACTION OF FAT BODY OF SILKWORM BOMBYX MORI L.

The oxidation of NADPH by the soluble fraction of the larval fat body of the silkworm, Bombyx mori L., was enhanced by adding both malonyl CoA and acetyl CoA, but no oxidation was observed in the absence of either malonyl CoA or acetyl CoA. This enzyme system seems to be related to fatty acid synthesis in the fat body. The NADPH oxidation activity was high in the fat body, whereas it was very low in the midgut and the intersegmental muscle. Maximal activity was obtained at pH 6·8. This oxidative system required NADPH exclusively, not NADH. This enzyme system for NADPH oxidation proved to be linked with G-6-P and 6-PG dehydrogenases, suggesting the association of the pentose phosphate pathway with fatty acid synthesis in the fat body of the silkworm. © 1968.