Characterization of Bacillus anthracis arginase

Arginase (RocF) hydrolyzes L-arginine to L-ornithine and urea.While previously characterized arginases have an alkaline pHoptimum and require activation with manganese, arginase fromHelicobacter pylori is optimally active with cobalt at pH 6. The arginase from Bacillus anthracis is not well characterized;therefore, this arginase was investigated by a variety ofstrategies and the enzyme was purified. pylori arginase and displayed remarkable activity in the absence ofexogenous metals, although manganese, cobalt, cobalt and nickel allimproved activity. Optimal B. Using a viable cell arginase assay, B. anthracis arginase increaseddramatically when the cells were grown with manganese, even atfinal concentrations of <1 microM, whereas B. anthracis grown with cobalt or nickel (>500 microM) showed nosuch increase, suggesting existence of a high affinity andspecificity manganese transporter.