Abstract
Formation and hydrolysis of IAA-amino acid conjugates (IAA-aa) play an important role in IAA homeostasis. We designed and synthesized the inhibitors of IAA-aa amidohydrolases that may serve as useful chemical tools to understand IAA homeostasis by chemical knockout of the IAA-aa hydrolytic pathways. Four enzymes including ILR1 have been reported as the amidohydrolases. These enzymes have different substrate specificities for the amino acid moiety of IAA-aa and require a divalent metal ion such as Mn2+ for activity. Hence we synthesized five inhibitors on the basis of the reaction mechanism of metalloproteinases. The inhibitors contain the moieties that mimic both IAA and the amino acid side chain and are expected to inhibit each amidohydrolase selectively depending on its substrate specificity. We have found that the inhibitors have inhibitory activity for the recombinant IAA-aa amidohydrolases expressed in E. coli. We report the detailed results on the synthesis and the inhibitory studies.
