摘要:
Some alpha-aminophosphonamidates which may mimic the transition state of D-alanine: D-alanine ligase catalytic reaction have been synthesized. The inhibition of the ligase by these compounds was investigated with Streptococcus faecalis enzyme using [C-14]-D-Ala assay. Apparent K(i) values analyzed by Dixon plots are in the same range as the apparent K(m). These compounds exhibit a time-dependent inhibition in the presence of ATP, suggesting that they undergo phosphorylation prior to inactivating the enzyme. The (enzyme-inhibitor-ATP) complex apparently dissociates very slowly, showing a process of slow binding inhibition. These results are consistent with the mechanistic model recently postulated for the inhibition of the ligase of Salmonella typhimurium by phosphinic acids.