Skip to main content
Log in

Effect of cobalt on Escherichia coli metabolism and metalloporphyrin formation

  • Published:
BioMetals Aims and scope Submit manuscript

Abstract

Toxicity in Escherichia coli resulting from high concentrations of cobalt has been explained by competition of cobalt with iron in various metabolic processes including Fe–S cluster assembly, sulfur assimilation, production of free radicals and reduction of free thiol pool. Here we present another aspect of increased cobalt concentrations in the culture medium resulting in the production of cobalt protoporphyrin IX (CoPPIX), which was incorporated into heme proteins including membrane-bound cytochromes and an expressed human cystathionine beta-synthase (CBS). The presence of CoPPIX in cytochromes inhibited their electron transport capacity and resulted in a substantially decreased respiration. Bacterial cells adapted to the increased cobalt concentration by inducing a modified mixed acid fermentative pathway under aerobiosis. We capitalized on the ability of E. coli to insert cobalt into PPIX to carry out an expression of CoPPIX-substituted heme proteins. The level of CoPPIX-substitution increased with the number of passages of cells in a cobalt-containing medium. This approach is an inexpensive method to prepare cobalt-substituted heme proteins compared to in vitro enzyme reconstitution or in vivo replacement using metalloporphyrin heme analogs and seems to be especially suitable for complex heme proteins with an additional coenzyme, such as human CBS.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6

Similar content being viewed by others

Abbreviations

AdoMet:

S-adenosyl-l-methionine

δ-ALA:

δ-Aminolevulinic acid

AMP:

Adenosine monophosphate

BSA:

Bovine serum albumin

CBS:

Cystathionine β-synthase

Co:

Cobalt

ETF:

Electron transfer flavoprotein

ETF-QO:

ETF ubiquinone oxidoreductase

FAD:

Flavin adenine dinucleotide

Fe:

Iron

GST:

Glutathione S-transferase

ICP-OES:

Inductively coupled plasma optical emission spectroscopy.

IPTG:

Isopropyl-β-d-1-thiogalactopyranoside

IscS:

Cysteine desulfurase

MIC:

Minimum inhibitory concentration

PLP:

Pyridoxal-5′-phosphate

PPIX:

Protoporphyrin IX

SEM:

Standard error of the mean

ThiH:

Tyrosine lyase

WT:

Wild type

References

Download references

Acknowledgements

This work was supported by Postdoctoral Fellowship 0920079G from the American Heart Association (to TM), by National Institutes of Health Grant HL065217 (to JPK), by American Heart Association Grant In-Aid 09GRNT2110159 and by a grant from the Jerome Lejeune Foundation (to JPK). The authors thank Dr. James P. McEvoy (Regis University, Denver) for assistance with measuring of cells oxygen uptake, Cheryl K. Peck (University of Colorado, Denver) for assistance with GC/MS analysis and Katherine M. Freeman and Judith N. Burstyn (University of Wisconsin, Madison) for helpful comments and critical reading of the manuscript.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Jan P. Kraus.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Majtan, T., Frerman, F.E. & Kraus, J.P. Effect of cobalt on Escherichia coli metabolism and metalloporphyrin formation. Biometals 24, 335–347 (2011). https://doi.org/10.1007/s10534-010-9400-7

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10534-010-9400-7

Keywords

Navigation