title: Changes in protein expression in Burkholderia vietnamiensis PR1 301 at pH 5 and 7 with and without nickel.
abstract: Burkholderia vietnamiensis PR1(301) (PR1) exhibits pH-dependent nickel (Ni) tolerance, with lower Ni toxicity observed at pH 5 than at pH 7. The Ni tolerance mechanism in PR1 is currently unknown, and traditional mechanisms of Ni resistance do not appear to be present. Therefore, 2D gel electrophoresis was used to examine changes in protein expression in PR1 with and without Ni (3.4 mM) at pH 5 and 7. Proteins with both a statistically significant and at least a twofold difference in expression level between conditions (pH, Ni) were selected and identified using MALDI-TOF-MS or LC-MS. Results showed increased expression of proteins involved in cell shape and membrane composition at pH 5 compared with pH 7. Scanning electron microscopy indicated elongated cells at pH 5 and 6 compared with pH 7 in the absence of Ni. Fatty acid methyl ester analysis showed a statistically significant difference in the percentages of long- and short-chain fatty acids at pH 5 and 7. These findings suggest that changes in membrane structure and function may be involved in the ability of PR1 to grow at higher concentrations of Ni at pH 5 than at pH 7.
authors.affiliation: Marine Biomedicine and Environmental Sciences Center, Medical University of South Carolina, 221 Fort Johnson Rd, Charleston, SC 29412, USA.
authors.forename: Joy D
authors.initials: JD
authors.lastname: Van Nostrand
authors.affiliation: Department of Medicine, Medical University of South Carolina, PO Box 250623, Charleston, SC 29425, USA.
authors.forename: John M
authors.initials: JM
authors.lastname: Arthur
authors.affiliation: NIST, Hollings Marine Laboratory, 331 Fort Johnson Rd, Charleston, SC 29412, USA.
authors.forename: Lisa E
authors.initials: LE
authors.lastname: Kilpatrick
authors.affiliation: Marine Biomedicine and Environmental Sciences Center, Medical University of South Carolina, 221 Fort Johnson Rd, Charleston, SC 29412, USA.
authors.forename: Benjamin A
authors.initials: BA
authors.lastname: Neely
authors.affiliation: University of Kentucky, Department of Plant and Soil Sciences, 1405 Veterans Drive, Lexington, KY 40546, USA.|Marine Biomedicine and Environmental Sciences Center, Medical University of South Carolina, 221 Fort Johnson Rd, Charleston, SC 29412, USA.
authors.forename: Paul M
authors.initials: PM
authors.lastname: Bertsch
authors.affiliation: National Ocean Service, Hollings Marine Laboratory, 331 Fort Johnson Rd, Charleston, SC 29412, USA.|Department of Cell Biology and Anatomy, Medical University of South Carolina, PO 173 Ashley Avenue, Charleston, SC 29425, USA.|Marine Biomedicine and Environmental Sciences Center, Medical University of South Carolina, 221 Fort Johnson Rd, Charleston, SC 29412, USA.
authors.forename: Pamela J
authors.initials: PJ
authors.lastname: Morris
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D042602:Burkholderia cepacia complex / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D015180:Electrophoresis, Gel, Two-Dimensional; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects*; D006863:Hydrogen-Ion Concentration; D009532:Nickel / Q000378:metabolism / Q000494:pharmacology*; D040901:Proteomics; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D001426:Bacterial Proteins; D009532:Nickel