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Dr Karrera Djoko's Outputs (34)

Mis-regulation of Zn and Mn homeostasis is a key phenotype of Cu stress in Streptococcus pyogenes. (2023)
Journal Article
Hong, Y., Mackenzie, E. S., Firth, S. J., Bolton, J. R. F., Stewart, L. J., Waldron, K. J., & Djoko, K. Y. (2023). Mis-regulation of Zn and Mn homeostasis is a key phenotype of Cu stress in Streptococcus pyogenes. Metallomics, 15(11), Article mfad064. https://doi.org/10.1093/mtomcs/mfad064

All bacteria possess homeostastic mechanisms that control the availability of micronutrient metals within the cell. Cross-talks between different metal homeostasis pathways within the same bacterial organism have been reported widely. In addition, th... Read More about Mis-regulation of Zn and Mn homeostasis is a key phenotype of Cu stress in Streptococcus pyogenes..

Structural and biochemical characterisation of the N‐carbamoyl‐β‐alanine amidohydrolase from Rhizobium radiobacterMDC 8606 (2023)
Journal Article
Paloyan, A., Sargsyan, A., Karapetyan, M. D., Hambardzumyan, A., Kocharov, S., Panosyan, H., Dyukova, K., Kinosyan, M., Krueger, A., Piergentili, C., Stanley, W. A., Djoko, K. Y., Baslé, A., Marles‐Wright, J., & Antranikian, G. (2023). Structural and biochemical characterisation of the N‐carbamoyl‐β‐alanine amidohydrolase from Rhizobium radiobacterMDC 8606. The FEBS Journal, 290(23), 5566-5580. https://doi.org/10.1111/febs.16943

N-carbamoyl-β-alanine amidohydrolase (CβAA) constitutes one of the most important groups of industrially relevant enzymes used in the production of optically pure amino acids and derivatives. In this study, a CβAA-encoding gene from Rhizobium radioba... Read More about Structural and biochemical characterisation of the N‐carbamoyl‐β‐alanine amidohydrolase from Rhizobium radiobacterMDC 8606.

Control of nutrient metal availability during host-microbe interactions: beyond nutritional immunity (2023)
Journal Article
Djoko, K. Y. (2023). Control of nutrient metal availability during host-microbe interactions: beyond nutritional immunity. JBIC Journal of Biological Inorganic Chemistry, 28(5), 451-456. https://doi.org/10.1007/s00775-023-02007-z

The control of nutrient availability is an essential ecological function of the host organism in host-microbe systems. Although often overshadowed by macronutrients such as carbohydrates, micronutrient metals are known as key drivers of host-microbe... Read More about Control of nutrient metal availability during host-microbe interactions: beyond nutritional immunity.

The Synergy between Zinc and Antimicrobial Peptides: An Insight into Unique Bioinorganic Interactions (2023)
Journal Article
Donaghy, C., Javellana, J. G., Hong, Y.-J., Djoko, K., & Angeles-Boza, A. M. (2023). The Synergy between Zinc and Antimicrobial Peptides: An Insight into Unique Bioinorganic Interactions. Molecules, 28(5), Article 2156. https://doi.org/10.3390/molecules28052156

Antimicrobial peptides (AMPs) are essential components of innate immunity across all species. AMPs have become the focus of attention in recent years, as scientists are addressing antibiotic resistance, a public health crisis that has reached epidemi... Read More about The Synergy between Zinc and Antimicrobial Peptides: An Insight into Unique Bioinorganic Interactions.

Salivary Antimicrobial Peptide Histatin-5 Does Not Display Zn(II)-Dependent or -Independent Activity against Streptococci (2023)
Journal Article
Stewart, L. J., Hong, Y., Holmes, I. R., Firth, S. J., Ahmed, Y., Quinn, J., Santos, Y., Cobb, S. L., Jakubovics, N. S., & Djoko, K. Y. (2023). Salivary Antimicrobial Peptide Histatin-5 Does Not Display Zn(II)-Dependent or -Independent Activity against Streptococci. ACS Infectious Diseases, 9(3), 631-642. https://doi.org/10.1021/acsinfecdis.2c00578

Histatin-5 (Hst5) is a member of the histatin superfamily of cationic, His-rich, Zn(II)-binding peptides in human saliva. Hst5 displays antimicrobial activity against fungal and bacterial pathogens, often in a Zn(II)-dependent manner. In contrast, he... Read More about Salivary Antimicrobial Peptide Histatin-5 Does Not Display Zn(II)-Dependent or -Independent Activity against Streptococci.

Copper Cytotoxicity: Cellular Casualties of Noncognate Coordination Chemistry (2022)
Journal Article
O’Hern, C. I., & Djoko, K. Y. (2022). Copper Cytotoxicity: Cellular Casualties of Noncognate Coordination Chemistry. mBio, 13(3), e00434-22. https://doi.org/10.1128/mbio.00434-22

Copper (Cu) is an essential micronutrient for cells, but in excess it is cytotoxic. How Cu is cytotoxic is the subject of recent work by L. Zuily, N. Lahrach, R. Fassler, O. Genest, et al. (mBio 13:e03251-21, 2022, https://doi.org/10.1128/mbio.03251-... Read More about Copper Cytotoxicity: Cellular Casualties of Noncognate Coordination Chemistry.

Streptococcus pyogenes Hijacks Host Glutathione for Growth and Innate Immune Evasion (2022)
Journal Article
Brouwer, S., Jespersen, M. G., Ong, C.-L. Y., De Oliveira, D. M., Keller, B., Cork, A. J., Djoko, K. Y., Davies, M. R., & Walker, M. J. (2022). Streptococcus pyogenes Hijacks Host Glutathione for Growth and Innate Immune Evasion. mBio, 13(3), https://doi.org/10.1128/mbio.00676-22

The nasopharynx and the skin are the major oxygen-rich anatomical sites for colonization by the human pathogen Streptococcus pyogenes (group A Streptococcus [GAS]). To establish infection, GAS must survive oxidative stress generated during aerobic me... Read More about Streptococcus pyogenes Hijacks Host Glutathione for Growth and Innate Immune Evasion.

The suppressor of copper sensitivity protein C from Caulobacter crescentus is a trimeric disulfide isomerase that binds copper(I) with subpicomolar affinity (2022)
Journal Article
Petit, G. A., Hong, Y., Djoko, K. Y., Whitten, A. E., Furlong, E. J., McCoy, A. J., Gulbis, J. M., Totsika, M., Martin, J. L., & Halili, M. A. (2022). The suppressor of copper sensitivity protein C from Caulobacter crescentus is a trimeric disulfide isomerase that binds copper(I) with subpicomolar affinity. Acta Crystallographica Section D: Structural Biology, 78(3), https://doi.org/10.1107/s2059798322000729

The introduction of disulfide bonds into periplasmic proteins is a critical process in many Gram-negative bacteria. The formation and regulation of protein disulfide bonds have been linked to the production of virulence factors. Understanding the dif... Read More about The suppressor of copper sensitivity protein C from Caulobacter crescentus is a trimeric disulfide isomerase that binds copper(I) with subpicomolar affinity.

Role of Glutathione in Buffering Excess Intracellular Copper in Streptococcus pyogenes (2020)
Journal Article
Stewart, L. J., Ong, C.-L. Y., Zhang, M. M., Brouwer, S., McIntyre, L., Davies, M. R., Walker, M. J., McEwan, A. G., Waldron, K. J., & Djoko, K. Y. (2020). Role of Glutathione in Buffering Excess Intracellular Copper in Streptococcus pyogenes. mBio, 11(6), e02804-20. https://doi.org/10.1128/mbio.02804-20

Copper (Cu) is an essential metal for bacterial physiology but in excess it is bacteriotoxic. To limit Cu levels in the cytoplasm, most bacteria possess a transcriptionally responsive system for Cu export. In the Gram-positive human pathogen Streptoc... Read More about Role of Glutathione in Buffering Excess Intracellular Copper in Streptococcus pyogenes.

Group A Streptococcus co-ordinates manganese import and iron efflux in response to hydrogen peroxide stress (2019)
Journal Article
Turner, A. G., Djoko, K. Y., Ong, C.-L. Y., Barnett, T. C., Walker, M. J., & McEwan, A. G. (2019). Group A Streptococcus co-ordinates manganese import and iron efflux in response to hydrogen peroxide stress. Biochemical Journal, 476(3), 595-611. https://doi.org/10.1042/bcj20180902

Bacterial pathogens encounter a variety of adverse physiological conditions during infection, including metal starvation, metal overload and oxidative stress. Here we demonstrate that group A Streptococcus (GAS) utilizes Mn(II) import via MtsABC duri... Read More about Group A Streptococcus co-ordinates manganese import and iron efflux in response to hydrogen peroxide stress.

Handling of nutrient copper in the bacterial envelope (2018)
Journal Article
Stewart, L. J., Thaqi, D., Kobe, B., McEwan, A. G., Waldron, K. J., & Djoko, K. Y. (2019). Handling of nutrient copper in the bacterial envelope. Metallomics, 11(1), 50-63. https://doi.org/10.1039/c8mt00218e

In bacteria, copper (Cu) is often recognised for its potential toxicity and its antibacterial activity is now considered a key component of the mammalian innate immune system. Cu ions bound in weak sites can catalyse harmful redox reactions while Cu... Read More about Handling of nutrient copper in the bacterial envelope.

Copper ions and coordination complexes as novel carbapenem adjuvants (2018)
Journal Article
Djoko, K. Y., Achard, M. E., Phan, M., Lo, A. W., Miraula, M., Prombhul, S., …Schembri, M. A. (2018). Copper ions and coordination complexes as novel carbapenem adjuvants. Antimicrobial Agents and Chemotherapy, 62(2), e02280-17. https://doi.org/10.1128/aac.02280-17

Carbapenem-resistant Enterobacteriaceae are an urgent threat to global human health. These organisms produce β-lactamases with carbapenemase activity, such as the metallo-β-lactamase NDM-1, which is notable due to its association with mobile genetic... Read More about Copper ions and coordination complexes as novel carbapenem adjuvants.

Copper(II)-bis(thiosemicarbazonato) complexes as anti-chlamydial agents (2017)
Journal Article
Marsh, J. W., Djoko, K. Y., McEwan, A. G., & Huston, W. M. (2017). Copper(II)-bis(thiosemicarbazonato) complexes as anti-chlamydial agents. Pathogens and Disease, 75(7), Article ftx084. https://doi.org/10.1093/femspd/ftx084

Lipophilic copper (Cu)-containing complexes have shown promising antibacterial activity against a range of bacterial pathogens. To examine the susceptibility of the intracellular human pathogen Chlamydia trachomatis to copper complexes containing bis... Read More about Copper(II)-bis(thiosemicarbazonato) complexes as anti-chlamydial agents.

Interplay between tolerance mechanisms to copper and acid stress in Escherichia coli (2017)
Journal Article
Djoko, K. Y., Phan, M., Peters, K. M., Walker, M. J., Schembri, M. A., & McEwan, A. G. (2017). Interplay between tolerance mechanisms to copper and acid stress in Escherichia coli. Proceedings of the National Academy of Sciences, 114(26), 6818-6823. https://doi.org/10.1073/pnas.1620232114

Copper (Cu) is a key antibacterial component of the host innate immune system and almost all bacterial species possess systems that defend against the toxic effects of excess Cu. The Cu tolerance system in Gram-negative bacteria is composed minimally... Read More about Interplay between tolerance mechanisms to copper and acid stress in Escherichia coli.

The PerR-Regulated P1B-4-Type ATPase (PmtA) Acts as a Ferrous Iron Efflux Pump in Streptococcus pyogenes (2017)
Journal Article
Turner, A. G., Ong, C. Y., Djoko, K. Y., West, N. P., Davies, M. R., McEwan, A. G., & Walker, M. J. (2017). The PerR-Regulated P1B-4-Type ATPase (PmtA) Acts as a Ferrous Iron Efflux Pump in Streptococcus pyogenes. Infection and Immunity, 85(6), Article e00140-17. https://doi.org/10.1128/iai.00140-17

Streptococcus pyogenes (group A Streptococcus [GAS]) is an obligate human pathogen responsible for a broad spectrum of human disease. GAS has a requirement for metal homeostasis within the human host and, as such, tightly modulates metal uptake and e... Read More about The PerR-Regulated P1B-4-Type ATPase (PmtA) Acts as a Ferrous Iron Efflux Pump in Streptococcus pyogenes.

Structural basis of thiol-based regulation of formaldehyde detoxification in H. influenzae by a MerR regulator with no sensor region (2016)
Journal Article
Couñago, R. M., Chen, N. H., Chang, C., Djoko, K. Y., McEwan, A. G., & Kobe, B. (2016). Structural basis of thiol-based regulation of formaldehyde detoxification in H. influenzae by a MerR regulator with no sensor region. Nucleic Acids Research, 44(14), 6981-6993. https://doi.org/10.1093/nar/gkw543

Pathogenic bacteria such as Haemophilus influenzae, a major cause of lower respiratory tract diseases, must cope with a range of electrophiles generated in the host or by endogenous metabolism. Formaldehyde is one such compound that can irreversibly... Read More about Structural basis of thiol-based regulation of formaldehyde detoxification in H. influenzae by a MerR regulator with no sensor region.

Formaldehyde Stress Responses in Bacterial Pathogens (2016)
Journal Article
Chen, N. H., Djoko, K. Y., Veyrier, F. J., & McEwan, A. G. (2016). Formaldehyde Stress Responses in Bacterial Pathogens. Frontiers in Microbiology, 7, Article 257. https://doi.org/10.3389/fmicb.2016.00257

Formaldehyde is the simplest of all aldehydes and is highly cytotoxic. Its use and associated dangers from environmental exposure have been well documented. Detoxification systems for formaldehyde are found throughout the biological world and they ar... Read More about Formaldehyde Stress Responses in Bacterial Pathogens.

Copper(II)-Bis(Thiosemicarbazonato) Complexes as Antibacterial Agents: Insights into Their Mode of Action and Potential as Therapeutics (2015)
Journal Article
Djoko, K. Y., Goytia, M. M., Donnelly, P. S., Schembri, M. A., Shafer, W. M., & McEwan, A. G. (2015). Copper(II)-Bis(Thiosemicarbazonato) Complexes as Antibacterial Agents: Insights into Their Mode of Action and Potential as Therapeutics. Antimicrobial Agents and Chemotherapy, 59(10), 6444-6453. https://doi.org/10.1128/aac.01289-15

There is increasing interest in the use of lipophilic copper (Cu)-containing complexes to combat bacterial infections. In this work, we showed that Cu complexes with bis(thiosemicarbazone) ligands [Cu(btsc)] exert antibacterial activity against a ran... Read More about Copper(II)-Bis(Thiosemicarbazonato) Complexes as Antibacterial Agents: Insights into Their Mode of Action and Potential as Therapeutics.

The Role of Copper and Zinc Toxicity in Innate Immune Defense against Bacterial Pathogens (2015)
Journal Article
Djoko, K. Y., Ong, C. Y., Walker, M. J., & McEwan, A. G. (2015). The Role of Copper and Zinc Toxicity in Innate Immune Defense against Bacterial Pathogens. Journal of Biological Chemistry, 290(31), 18954-18961. https://doi.org/10.1074/jbc.r115.647099

Zinc (Zn) and copper (Cu) are essential for optimal innate immune function, and nutritional deficiency in either metal leads to increased susceptibility to bacterial infection. Recently, the decreased survival of bacterial pathogens with impaired Cu... Read More about The Role of Copper and Zinc Toxicity in Innate Immune Defense against Bacterial Pathogens.