Differential expression of proteins in Pseudomonas mendocina SMSKVR‐3 under arsenate stress

Abstract

This study focuses on analyzing the protein expression pattern of intracellular proteins when Pseudomonas mendocina SMSKVR‐3 exposed to 300 mM of arsenate to find out the proteins that are overexpressed or exclusively expressed in response to arsenate. The sodium dodecyl sulfate‐polyacrylamide gel electrophoresis analysis of protein expression at different time intervals showed the highest number of protein bands (14) that are overexpressed at 8 h of the time interval. It was also observed that treatment with at least 200 mM of As(V) is required to induce a difference in protein expression. Two‐dimensional (2D)‐PAGE analysis of 8‐h sample exhibited 146 unique spots, 45 underexpressed, and 46 overexpressed spots in arsenate‐treated sample. Based on the highest percent volume and fold change, three unique spots and one overexpressed spot were selected and analyzed by matrix‐assisted laser desorption/ionization‐time of flight (MALDI‐TOF/TOF) mass spectrometry (MS) analysis followed by the MASCOT search. These proteins were identified as ribosome‐recycling factor (20.13 kDa), polyphosphate:ADP/GDP phosphotransferase (40.88 kDa), ribonuclease P protein component (14.96 kDa) and cobalt‐precorrin‐5B C(1)‐methyltransferase (38.43 kDa) with MASCOT score of 54, 81, 94, and 100, respectively. All of these proteins help the bacteria to overcome arsenate stress.