TY - JOUR
T1 - Quantitative proteomic profiling of the Escherichia coli response to metallic copper surfaces
AU - Nandakumar, Renu
AU - Santo, Christophe Espirito
AU - Madayiputhiya, Nandakumar
AU - Grass, Gregor
N1 - Funding Information:
Acknowledgments The mass spectrometry analysis was conducted at the Proteomic and Metabolomic Core facility, Redox biology center, UNL and the research was supported by NIH Grant Number P20 RR-17675, from the National Center for Research Resources. The contents of this article are solely the responsibility of the authors and do not represent the official views of the NIH. We also acknowledge funds from the International Copper Association (ICA), the Copper Development Association (CDA), and a University of Nebraska-Lincoln Office of Research Faculty Seed grant to G.G. C.E.S. was supported by a Fundac¸ão para a Ciência e Tecnologia, Portugal, graduate fellowship.
PY - 2011/6
Y1 - 2011/6
N2 - Metallic copper surfaces have strong antimicrobial properties and kill bacteria, such as Escherichia coli, within minutes in a process called contact killing. These bacteria are exposed to acute copper stress under dry conditions which is different from chronic copper stress in growing liquid cultures. Currently, the physiological changes of E. coli during the acute contact killing process are largely unknown. Here, a label-free, quantitative proteomic approach was employed to identify the differential proteome profiles of E. coli cells after sub-lethal and lethal exposure to dry metallic copper. Of the 509 proteins identified, 110 proteins were differentially expressed after sub-lethal exposure, whereas 136 proteins had significant differences in their abundance levels after lethal exposure to copper compared to unexposed cells. A total of 210 proteins were identified only in copper-responsive proteomes. Copper surface stress coincided with increased abundance of proteins involved in secondary metabolite biosynthesis, transport and catabolism, including efflux proteins and multidrug resistance proteins. Proteins involved in translation, ribosomal structure and biogenesis functions were down-regulated after contact to metallic copper. The set of changes invoked by copper surface-exposure was diverse without a clear connection to copper ion stress but was different from that caused by exposure to stainless steel. Oxidative posttranslational modifications of proteins were observed in cells exposed to copper but also from stainless steel surfaces. However, proteins from copper stressed cells exhibited a higher degree of oxidative proline and threonine modifications.
AB - Metallic copper surfaces have strong antimicrobial properties and kill bacteria, such as Escherichia coli, within minutes in a process called contact killing. These bacteria are exposed to acute copper stress under dry conditions which is different from chronic copper stress in growing liquid cultures. Currently, the physiological changes of E. coli during the acute contact killing process are largely unknown. Here, a label-free, quantitative proteomic approach was employed to identify the differential proteome profiles of E. coli cells after sub-lethal and lethal exposure to dry metallic copper. Of the 509 proteins identified, 110 proteins were differentially expressed after sub-lethal exposure, whereas 136 proteins had significant differences in their abundance levels after lethal exposure to copper compared to unexposed cells. A total of 210 proteins were identified only in copper-responsive proteomes. Copper surface stress coincided with increased abundance of proteins involved in secondary metabolite biosynthesis, transport and catabolism, including efflux proteins and multidrug resistance proteins. Proteins involved in translation, ribosomal structure and biogenesis functions were down-regulated after contact to metallic copper. The set of changes invoked by copper surface-exposure was diverse without a clear connection to copper ion stress but was different from that caused by exposure to stainless steel. Oxidative posttranslational modifications of proteins were observed in cells exposed to copper but also from stainless steel surfaces. However, proteins from copper stressed cells exhibited a higher degree of oxidative proline and threonine modifications.
KW - Copper surfaces
KW - Escherichia coli
KW - Posttranslational modification
KW - Quantitative proteomics
UR - http://www.scopus.com/inward/record.url?scp=79959928955&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=79959928955&partnerID=8YFLogxK
U2 - 10.1007/s10534-011-9434-5
DO - 10.1007/s10534-011-9434-5
M3 - Article
C2 - 21384090
AN - SCOPUS:79959928955
VL - 24
SP - 429
EP - 444
JO - BioMetals
JF - BioMetals
SN - 0966-0844
IS - 3
ER -