PNNL

Abstract

A global proteomic evaluation of the response of Arthrobacter sp. strain FB24 to 5 mM and 20 mM Cr(VI) was conducted using both two-dimensional gel electrophoresis (2-DGE) and liquid chromatography coupled to tandem mass spectrometry (LC/LC-MS/MS). The changes in protein expression found with 2-DGE indicate alterations in central metabolism and amino acid synthesis. Proteome coverage increased from 22% with 2-DGE to 71% with LC/LC-MS/MS. The proteins exhibiting the highest levels of expression under Cr(VI) stress suggest intracellular sulfur limitation, which could be driven by competition for the sulfate (SO42-) transporter by the chromate (CrO42-) ion. These results are consistent with the growth defects seen with strain FB24 when Cr(VI) concentrations exceed 5 mM.