title: Isoleucine hydroxamate, an isoleucine antagonist.
abstract: Isoleucine hydroxamate (Ile.Hdx) was found to inhibit the growth of Serratia marcescens and to antagonize isoleucine. At a low concentration of Ile.Hdx, at which the growth of the wild strain was completely inhibited, the growth of an isoleucine auxotroph was not inhibited in the medium containing a limiting amount of d-threonine as the isoleucine source. At a higher concentration, this antagonist exhibited a considerable inhibitory effect on the growth of the auxotroph. Ile.Hdx showed the same inhibitory effect as isoleucine on l-threonine dehydratase activity at the concentrations 10 times those of isoleucine. Ile.Hdx caused also derepression of isoleucine-valine biosynthetic enzymes and the derepression was overcome by isoleucine. These results indicate the Ile.Hdx causes growth inhibition by its effects on isoleucine metabolism.
mesh_terms: D055598:Chemical Phenomena; D002621:Chemistry; D003470:Culture Media; D003720:Densitometry; D006836:Hydro-Lyases / Q000378:metabolism; D006877:Hydroxamic Acids / Q000494:pharmacology; D007532:Isoleucine / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000494:pharmacology*; D008025:Ligases / Q000378:metabolism; D012706:Serratia marcescens / Q000187:drug effects* / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism; D013912:Threonine; D000637:Transaminases / Q000378:metabolism; D014633:Valine / Q000096:biosynthesis
chemical_list: D003470:Culture Media; D006877:Hydroxamic Acids; D007532:Isoleucine; D013912:Threonine; D000637:Transaminases; D006836:Hydro-Lyases; D008025:Ligases; D014633:Valine