Negative functional interference between two active centers is indicated in animal fatty acid synthetase.

When fatty acid synthetase of the Harderian gland of guinea-pig was treated with various amounts of phenylmethanesulfonyl fluoride, the overall activity of the enzyme showed a quadratic decrease with respect to the inhibition degree of the thioesterase activity which was the primary target of inhibition. Moreover, the overall activity per active center of a heterodimer, which was formed between the native monomer and the thioesterase-less monomer, was higher than that of the native enzyme. These results are consistent with the view that the two active centers of the native enzyme exhibit a negative interference to each other.