A full list of publications can be found on Google Scholar.
Structural characterization of encapsulated ferritin provides insight into iron storage in bacterial nanocompartments. eLife 2016, 5, e18972. DOI: 10.7554/eLife.18972
Ferritins are ubiquitous proteins that oxidise and store iron within a protein shell to protect cells from oxidative damage. We have characterized the structure and function of a new member of the ferritin superfamily that is sequestered within an encapsulin capsid. We show that this encapsulated ferritin (EncFtn) has two main alpha helices, which assemble in a metal dependent manner to form a ferroxidase center at a dimer interface. EncFtn adopts an open decameric structure that is topologically distinct from other ferritins. While EncFtn acts as a ferroxidase, it cannot mineralize iron. Conversely, the encapsulin shell associates with iron, but is not enzymatically active, and we demonstrate that EncFtn must be housed within the encapsulin for iron storage. This encapsulin nanocompartment is widely distributed in bacteria and archaea and represents a distinct class of iron storage system, where the oxidation and mineralization of iron are distributed between two proteins.
Desalting Large Protein Complexes during Native Electrospray Mass Spectrometry by Addition of Amino Acids to the Working Solution. Analyst, 2015, 140, 2679-2686. DOI: 10.1039/C4AN02334J
In this paper we report our findings that the addition of 10 mM l-serine to electrospray solution reduces the adverse effects of sodium adduction to proteins. In the analysis of bovine serum albumin (BSA; 66 kDa), 10 mM serine increased signal to noise ratio (S/N) ∼4 fold. This increase in sensitivity was accompanied by peak narrowing (∼10 fold), which allowed more precise assignment of molecular mass. Similar effects were observed when analysing protein complexes - serine palmitoyl transferase (SPT, a 92 kDa homodimer), enolase (a 93 kDa homodimer); and alcohol dehydrogenase (ADH, a 148 kDa tetramer). Reduction in sodium ion adduction occurs with no loss of the non-covalent protein-protein interactions, and with little effect on the overall observed charge state-distribution. As a consequence of increasing signal intensity, the addition of serine to the ESI spray solution greatly improved the quality of the data obtained from native top-down electron-capture dissociation (ECD) experiments.
RECENT AND NOTEWORTHY
68. Native Ion Mobility Mass Spectrometry (IM‐MS) reveals that small organic acid fragments impart gas‐phase stability to carbonic anhydrase II. C.G.L. Veale, M. Mateos Jimenez, C.L. Mackay, D.J. Clarke. Rapid Comms Mass Spec 2019, in press. https://doi.org/10.1002/rcm.8570.
67. High resolution fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) for the characterisation of enzymatic processing of commercial lignin. V. Echavarri-Bravo, M. Tinzl, W. Kew, F. Cruickshank, C. L. Mackay, D. J. Clarke, L. E. Horsfall. New biotechnology. 2019, 52, 1-8. doi.org/10.1016/j.nbt.2019.03.001
66. Untargeted Metabolite Mapping in 3D Cell Culture Models Using High Spectral Resolution FT-ICR Mass Spectrometry Imaging. L. H. Tucker, G. R. Hamm, R. J. E. Sargeant, R. J.A. Goodwin, C. L. Mackay, C. J. Campbell, D. J. Clarke. Analytical Chem. 2019, 91, 9522-9529. doi.org/10.1021/acs.analchem.9b00661
65. Conservation of the structural and functional architecture of encapsulated ferritins in bacteria and archaea.
64. Use of isotopically labeled substrates reveals kinetic differences between human and bacterial serine palmitoyltransferase. P. J. Harrison, K. Gable, N. Somashekarappa, V. Kelly, D. J. Clarke, J. H. Naismith, T. M. Dunn, D. J. Campopiano. J. Lipid Research. 2019, 60, 953-962. doi: 10.1194/jlr.M089367.
63. S-nitrosylation of the zinc finger protein SRG1 regulates plant immunity. B. Cui, Q. Pan, D. J. Clarke, M. Ochoa Villarreal, S. Umbreen, B. Yuan, W. Shan, J. Jiang & G. J. Loake. Nature Comms. 2018, 9(1), 4226. doi: 10.1038/s41467-018-06578-3.
W. Kew, C. L. Mackay, I. Goodall, D. J. Clarke*, and D. Uhrin*. Anal. Chem. 2018, 90, 11265-11272. doi: 10.1021/acs.analchem.8b01446.
61. MALDI Matrix Application Utilizing a Modified 3D Printer for Accessible High Resolution Mass Spectrometry Imaging. L. Tucker, A. Conde-González, D. Cobice, G. Hamm, R. J. A. Goodwin, C. J. Campbell, D. J. Clarke, C. L. Mackay. Anal. Chem. 2018, 90, 8742–8749. doi: 10.1021/acs.analchem.8b00670
60. Autopiquer - a Robust and Reliable Peak Detection Algorithm for Mass Spectrometry. D. P. A. Kilgour, S. Hughes, S. L. Kilgour, C. L. Mackay, M. Palmblad, B. Q. Tran, Y. Ah Goo, R. K. Ernst, D. J. Clarke, D. R. Goodlett. J. Am. Soc. Mass Spec. 2017, 28, 253-262. doi: 10.1007/s13361-016-1549-z.
59. Chemical Diversity and Complexity of Scotch Whisky as Revealed by High-Resolution Mass Spectrometry. W. Kew, I. Goodall, D. J. Clarke*, D. Uhrin*. J. Am. Soc. Mass Spec. 2017, 28, 200-213. doi:10.1007/s13361-016-1513-y.
58. Interactive van Krevelen diagrams – Advanced visualisation of mass spectrometry data of complex mixtures. W. Kew, J. Blackburn, D. J. Clarke, D. Uhrin. Rapid Comms. Mass. Spec. Volume 31, 2017, 7, 658–662. doi: 10.1002/rcm.7823.
57. L-1 beta-induced protection of keratinocytes against Staphylococcus aureus-secreted proteases is mediated by human beta defensin 2. B. Wang, B. J. McHugh, A. Qureshi, D. J. Campopiano, D.J. Clarke, J. R. Fitzgerald,J. Dorin, R. Weller, D. J. Davidson. J Invest. Dermatol. 2017,137, 95–105. doi: 10.1016/j.jid.2016.08.025.
56. Characterisation of homologous sphingosine 1-phosphate lyase (S1PL) isoforms in the bacterial pathogen Burkholderia pseudomallei. C. McLean, J. Marles-Wright, R. Custodio,J. Lowther, A. J. Kennedy, J. Pollock, D. J. Clarke, A. R. Brown, D. J. Campopiano. J. Lipid Res. 2017, 58, 137-150. doi: 10.1194/jlr.M071258.
55. Structural characterization of encapsulated ferritin provides insight into iron storage in bacterial nanocompartments. D. He, S. Hughes, S. Vanden-Hehir, A. Georgiev, K. Altenbach, E. Tarrant, C. L. Mackay, K. J. Waldron, D. J. Clarke*, J. Marles-Wright*. eLife 2016, 5:e18972. doi: 10.7554/eLife.18972
54. Determination of protein disulfide bond reduction potential by isotope labelling and intact mass measurement. S. E. Thurlow, D. P. Kilgour, D. J. Campopiano, C. L. Mackay, P. R. R. Langridge-Smith, D. J. Clarke*, C. J. Campbell*. Anal Chem 2016, 88, 2727–2733. doi: 10.1021/acs.analchem.5b04195.
53. The crystal structure of the propionaldehyde dehydrogenase enzyme from Clostridium phytofermentans with NAD+ and CoA in the active site provides insight into cofactor binding and the mechanism of acyl-transfer in acylating aldehyde dehydrogenase enzymes. L. R. Tuck, K. Altenbach, A. T. Fu, A. D. Crawshaw, D. J. Campopiano, D. J. Clarke, and J. Marles-Wright. Scientific Reports. 2016, 6, 22108. doi:10.1038/srep22108.
52. Mass spectrometry analysis of the oxidation states of the pro-oncogenic protein anterior gradient-2 reveals covalent dimerization via an intermolecular disulphide bond. D. J. Clarke*, E. Murray, J. Faktor, A. Mohtar, B. Vojtesek, C. L. MacKay, P. Langridge Smith, T. Hupp*. BBA: Proteins and Proteomics 2016, 1864 551-561.
51. New cytotoxic callipeltins from the Solomon Island marine sponge Asteropus sp. M. Stierhof, K. Ø. Hansen, M. Sharma, K. Feussner, K. Subko, F. F. Díaz-Rullo, J. Isaksson, I. Pérez-Victoria, D. J. Clarke, E. Hansen, M Jaspars, J. N. Tabudravua. Tetrahedron 2016, 72 (44), 6929-6934. Link.
50. Characterization of secreted sphingosine-1-phosphate lyases required for virulence and intracellular survival of Burkholderia pseudomallei. R. Custódio, C. J. McLean, A. E. Scott, J. Lowther, A. Kennedy, D. J. Clarke, D. J. Campopiano, M. Sarkar-Tyson, A. R. Brown. Mol Microbiol. 2016, 102, 1004-1019. doi: 10.1111/mmi.13531
49. Molecular basis of Streptococcus mutans sortase A inhibition by the flavonoid natural product trans-chalcone. D. J. Wallock-Richards, J. Marles-Wright, D. J. Clarke, A. Maitra, M. Dodds, B. Hanley, D. J. Campopiano. Chem Comm. 2015, 51, 10483-10485. doi: 10.1039/C5CC01816A.
48. Desalting Large Protein Complexes during Native Electrospray Mass Spectrometry by Addition of Amino Acids to the Working Solution. D. J. Clarke*, D. J. Campopiano. Analyst, 2015, 140, 2679-2686. doi: 10.1039/C4AN02334J
47. Insights into the Conformations of Three Structurally Diverse Proteins: Cytochrome c, p53, and MDM2, Provided by Variable-Temperature Ion Mobility Mass Spectrometry. E. R. Dickinson, E. Jurneczko, K. J. Pacholarz, D. J. Clarke, M. Reeves, K. L. Ball, T. Hupp, D. J. Campopiano, P. V. Nikolova, and P. E. Barran. Anal Chem 2015, 87, 3231-3238.
46. Dissecting the dynamic conformations of the metamorphic protein lymphotactin. Harvey, S.R., Porrini, M., Konijnenberg, A., Clarke, D.J., Tyler, R.C., Langridge-Smith, P.R., MacPhee, C.E., Volkman, B.F., Barran, P.E. J. Phy. Chem. B, 2014, 118, 12348-12359.
45. The chemical basis of serine palmitoyltransferase inhibition by myriocin. D. J. Clarke, J. M. Wadsworth, S. A. McMahon, J. P. Lowther, A. E. Beattie, H. Broughton, T. M. Dunn, J. H. Naismith, and D. J. Campopiano. J. Am. Chem. Soc., 2013, 135, 14276-14285. DOI: 10.1021/ja4059876
44. Probing the conformational diversity of cancer-associated mutations in p53 by Ion Mobility-Mass Spectrometry. E. Jurneczko, F. Cruickshank, M. Porrini, D. J. Clarke, I. D. G. Campuzano, M. Morris, P. V. Nikolova, and P. E. Barran. Angewandte Chemie Int. Ed., 2013, 52, 4370-4374.
43. Redox Regulation of Tumour Suppressor Protein p53: Identification of the Sites of Hydrogen Peroxide Oxidation and Glutathionylation. D. J. Clarke, J. Scotcher, C. L. Mackay, T. Hupp, P. J. Sadler, and P. R. R. Langridge-Smith. Chemical Science, 2013, 4, 1257-1269. DOI: 10.1039/C2SC21702C
42. Reconstitution of the pyridoxal 5’-phosphate (PLP) dependent enzyme serine palmitoyltransferase (SPT) with pyridoxal reveals a crucial role for the phosphate during catalysis. A. E. Beattie, D. J. Clarke, J. M. Wadsworth, J. Lowther, H. Sin and D. J. Campopiano. Chem. Comm., 2013, 49, 7058.
31. Mapping a Non-covalent Protein-Peptide Interface by Top-Down FT-ICR Mass Spectrometry using Electron Capture Dissociation. D. J. Clarke, E. Murray, T. Hupp, C. L. Mackay, and P. R. R. Langridge-Smith. J. Am. Soc. Mass Spec. 2011, 22 ,1432-1440.
30. Identification of Two Reactive Cysteine Residues in the Tumor Suppressor Protein p53 Using Top-Down FTICR Mass Spectrometry. J. Scotcher, D. J. Clarke, S. K. Weidt, C. L. Mackay, T. R. Hupp, P. J. Sadler, P. R. R. Langridge-Smith. J. Am. Soc. Mass Spec. 2011, 22, 888-897.
29. Online Quench-Flow Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry for Elucidating Kinetic and Chemical Enzymatic Reaction Mechanisms. D. J. Clarke, A. A. Stokes, P. R. R. Langridge-Smith, C. L. Mackay. Anal. Chem. 2010, 82, 1897-1904.
28. Subdivision of the bacterioferritin comigratory protein family of bacterial peroxiredoxins based on catalytic activity. D. J. Clarke, X. P. Ortega, C. L. Mackay, M. A. Valvano, J. Govan, D. J. Campopiano, P. Langridge-Smith and A. R. Brown. Biochemistry. 2010, 49, 1319-1330.
Redox Regulation of Tumour Suppressor Protein p53: Identification of the Sites of Hydrogen Peroxide Oxidation and Glutathionylation. Chemical Science, 2013, 4, 1257-1269. DOI: 10.1039/C2SC21702C
The p53 transcription factor is a key tumour suppressor protein. In this paper we analyze oxidation pathways in the p53 core domain by high resolution mass spectrometry and top-down fragmentation. Firstly, we show that p53 core domain is sensitive to oxidation by the reactive oxygen species (ROS) and that the zinc-coordination site is the initial target for ROS-induced oxidation. Two disulfide bonds are formed involving Cys182 and the three cysteines which coordinate to zinc (Cys176, 238 and 242). This disulfide bond formation is accompanied by loss of zinc from the binding site. Our work also highlights an additional cysteine, Cys277, is prone to oxidation via a ROS-independent mechanism. We discuss our findings in the context of redox regulation of p53 activity and in comparison to other redox regulated proteins.