Molecular weight and subunit size of rabbit mammary-gland fatty acid synthetase.

1. The molecular weights of fatty acid synthetases isolated from lactating rabbit, rat, cow and goat mammary glands were estimated by sucrose gradient centrifugation and compared by chromatography on Sepharose 6B. 2. The values obtained for all four enzymes were in the same range (0.40 X 10(6)-0.55 X 10(6)) as that found for other mammalian and avian fatty acid synthetases. The molecular weight found for the rabbit mammary enzyme therefore differs from published values of approx. 0.9 X 10(6). 3. The molecular weights of the subunits of these four synthetases were 225000-242000. Again, the value for the rabbit mammary enzyme differs from published values.