Effect of arsenate on inorganic phosphate transport in Escherichia coli.

摘要: The effect of arsenate on strains dependent the two major inorganic phosphate (Pi) transport systems in Escherichia coli was examined cells grown 1 mM medium. development arsenate-resistant Pi uptake a strain upon Pst (phosphate specific transport) system examined. growth rate Pst-dependent arsenate-containing medium function arsenate-to-Pi ratio. Growth not due to detoxification arsenate. Kinetic studies revealed that with 10-fold excess have almost twofold increase capacity (Vmax) for Pi, but maintained same affinity (Km). accumulation still sensitive changes ratio, and Ki (arsenate) 39 microM determined. did accumulate radioactive arsenate, showed only transient decrease intracellular adenosine triphosphate levels after added transport-dependent ceased media. This accumulated 74As-arsenate, pools were completely depleted addition Arsenate required metabolizable energy source inhibited by N-ethylmaleimide. Previously could exchange or