EFFECT OF THIOLACTOMYCIN ON FATTY-ACID SYNTHESIS IN PEAS

Thiolactomycin inhibited fatty acid synthesis in isolated pea chloropl asts. Using [1-C-14]acetate as a precursor, an I-50 value of ca 20 mu M was obtained for a (R,S) mixture of thiolactomycin. The antibiotic i nhibited the beta-ketoacyl-ACP synthase (condensing enzyme: KAS) and t he acetyl-CoA:ACP (ACAT) reactions. An examination of the relative inh ibition of the three condensing enzymes revealed that their order of s ensitivity to thiolactomycin was KAS II > KAS I > KAS III.