The herbicidally active experimental compound Hoe 704 is a potent inhibitor of the enzyme acetolactate reductoisomerase.
Growth inhibition of plants and bacteria by the experimental herbicide Hoe 704 (2-methylphosphinoyl-2-hydroxyacetic acid) was alleviated by the addition of the branched-chain amino acids to growth media. Hoe 704 caused a massive accumulation of acetoin and acetolactate, indicating its direct interference with the branched-chain amino acid biosynthetic pathway. The second enzyme of this pathway, acetolactate reductoisomerase (EC 1.1.1.86), was found to be subject to strong inhibition by Hoe 704. The inhibition was time-dependent and competitive with the enzyme's substrate, acetolactate. This report establishes acetolactate reductoisomerase as a new target for a herbicidal compound.
D015072:2-Acetolactate Mutase / Q000037:antagonists & inhibitors*; D000597:Amino Acids, Branched-Chain / Q000096:biosynthesis; D004926:Escherichia coli / Q000201:enzymology; D006540:Herbicides; D006885:Hydroxybutyrates / Q000378:metabolism; D007535:Isomerases / Q000037:antagonists & inhibitors*; D007700:Kinetics; D007711:Klebsiella pneumoniae / Q000187:drug effects; D007773:Lactates / Q000378:metabolism; D009943:Organophosphorus Compounds / Q000494:pharmacology*; D010944:Plants / Q000201:enzymology
D000597:Amino Acids, Branched-Chain; D006540:Herbicides; D006885:Hydroxybutyrates; D007773:Lactates; D009943:Organophosphorus Compounds; C027745:alpha-aceto-alpha-hydroxybutyrate; C006359:alpha-acetolactate; C057344:2-methylphosphinoyl-2-hydroxyacetic acid; D007535:Isomerases; D015072:2-Acetolactate Mutase