Alun Jones | University College Dublin (original) (raw)
Papers by Alun Jones
This section can introduce the researchers and provide an outline of the underpinning research. K... more This section can introduce the researchers and provide an outline of the underpinning research. Key contextual information such as timeframe, body of research, research project or programme along with the significance of this research in relation to the impact can be included.
European Urban and Regional Studies, 1995
concentrating 40 per cent of Czechoslovak vouchers in Kozeny’s hands. The government also feared ... more concentrating 40 per cent of Czechoslovak vouchers in Kozeny’s hands. The government also feared seeing so much economic power concentrated in the hands of people who granted Kozeny the finance and information needed for starting and maintaining his huge business. In 1994, after accusations of using secret police databases, Kozeny left for Switzerland. However, the crucial topics of mutual investment funds, influence in the Czech and Slovak economies, of insider dealing and of the origin of the capital needed for establishing such funds, remain unsolved. ’
Journal of Rural Studies, 1993
... The German government, in particular farm minister Ignaz Kiechle, is credited with convincing... more ... The German government, in particular farm minister Ignaz Kiechle, is credited with convincing other Community member states of the need for a set ... Case study 7 Surrounded by the forest of the Hunsruck lies the hamlet of Baldingen where Winfried H. described how his son had ...
Geopolitics, 2019
Where a licence is displayed above, please note the terms and conditions of the licence govern yo... more Where a licence is displayed above, please note the terms and conditions of the licence govern your use of this document. When citing, please reference the published version. Take down policy While the University of Birmingham exercises care and attention in making items available there are rare occasions when an item has been uploaded in error or has been deemed to be commercially or otherwise sensitive.
Geopolitics, 2011
The European Union (EU) is among the most prosperous, most developed and – by any conventional me... more The European Union (EU) is among the most prosperous, most developed and – by any conventional measure – potentially one of the most ‘powerful’ global actors of the twenty-first century. Nevertheless, there is a growing sense of incredulity among a widening range of policy actors, academics, political commentators and European publics over the seeming inability of the Union to present itself unambiguously and to act trenchantly on the international stage. Political scientists have furnished a number of explanations for the perceived international inadequacies of the EU. These centre upon the so-called capability-expectations gap in EU international action, arising from a combination of absence of political will and engagement among the Union’s constituent member states, clashes of historically conditioned national interests, insufficiencies in the EU’s foreign policy and security provisions, and/or weaknesses in the EU’s legal and decision-making structures. Other observers have preferred to see the EU as having its own particular form of international ‘actorness’ and ‘presence’ which creates a rather
Geoforum, 2013
1 cf. Berry's (2009, p. 393) recent comment on the lack of cross-disciplinary dialogue in his own... more 1 cf. Berry's (2009, p. 393) recent comment on the lack of cross-disciplinary dialogue in his own university: ''It was clear that most of the.. .political scientists were focused inward, on their own disciplinary concerns, by and for political scientists, and it was equally clear that political geographers had similarly territorialized world views and had been quite willing to push certain topics to the margins of that territory.''
European Urban and Regional Studies, 2013
In this paper we explore the current politico-economic tensions surrounding Iceland’s application... more In this paper we explore the current politico-economic tensions surrounding Iceland’s application for EU membership provoked by the state’s financial trauma of 2008. Through access to high level diplomats, politicians and EU Commission staff involved in preparing and negotiating Icelandic accession to the EU, we examine the difficulties for both sides of overcoming the country’s long-standing antipathy towards European political integration and appeasing the vociferous sectoral interests, especially in farming and fisheries, ranged against membership. The significance of this application far outstrips the size of this small island state since Iceland’s relationship with ‘EUrope’ is long-standing and complex. This national drama is given greater political salience as it is projected against the backdrop of ‘EUrope’s own existential struggles over the post-1945 political project of integration currently underway. Ultimately the saga of Iceland’s membership of the EU may be a relativel...
Environment and Planning D: Society and Space, 2011
Building on recent academic exchanges theorising sociospatial relations, we argue that it is not ... more Building on recent academic exchanges theorising sociospatial relations, we argue that it is not sociospatial concepts or metaphors per se that delineate the substance of such relations—rather it is the different politics by and through which these concepts are conceived, represented, and mobilised by elite actors. We make an empirically founded contribution to these exchanges by examining the context of the European Union's (EU) sociospatialities, illustrated specifically through central European elite activities in the wake of the 2004 accession to the EU. We show how central European elite assertions of sociospatial concepts were embroiled in complex ways with enactments of these sociospatialities—that is, how the assertion and performance of concepts such as space, territory, and positionality by elite actors created novel forms of politics which, subsequently, have become pivotal to the reconfiguration of contemporary EUropean space.
Tijdschrift voor economische en sociale geografie, 2016
Where a licence is displayed above, please note the terms and conditions of the licence govern yo... more Where a licence is displayed above, please note the terms and conditions of the licence govern your use of this document. When citing, please reference the published version. Take down policy While the University of Birmingham exercises care and attention in making items available there are rare occasions when an item has been uploaded in error or has been deemed to be commercially or otherwise sensitive.
Annals of the Association of American Geographers, 2009
The theory of "radical geopolitics" is directly concerned with identifying the roots of U.S. fore... more The theory of "radical geopolitics" is directly concerned with identifying the roots of U.S. foreign policy from a critical political economic perspective, seeking to determine the relative importance of political factors and economic forces in shaping foreign policy. It builds on Harvey's (2003) conceptualization of two logics of power and deploys a "geopolitical logic" and a "geoeconomic logic" to interpret political events. The former logic arises out of capitalism's tendency to expand geographically and the latter out of officials of statecraft's need to maintain their state's credibility internationally. Post-World War II U.S. foreign policy has largely followed the geoeconomic logic but has also been oriented (in sometimes divergent directions) by the geopolitical logic. A discussion of the Iranian nuclear "crisis" illustrates the radical geopolitics approach using national security documents outlining U.S. policy toward the Middle East and Iran, along with detailed interviews with senior diplomats from Iran, the United States, China, Russia, Germany, the United Kingdom, France, and the European Union. The Iranian crisis is a product of (1) American interest in the control of Iranian energy resources (a geoeconomic logic); and (2) American officials' need to reaffirm U.S. credibility in the face of Iranian defiance of U.S. hegemony in the Middle East (a geopolitical logic).
Transactions of the Institute of British Geographers
Since the mid-1990s much theoretical and empirical work in economic geography has been increasing... more Since the mid-1990s much theoretical and empirical work in economic geography has been increasingly focused upon a closer examination of the inter- meshing of the socio-spatial relations of actors with processes of economic change. This new focus in the sub-discipline has ...
Spine, 1998
A technique is described for analyzing electromyogram data from lumbar spinal muscles, with speci... more A technique is described for analyzing electromyogram data from lumbar spinal muscles, with special reference to discrimination of people with back pain. The ability to discriminate was evaluated in 99 people (61 healthy and 38 with chronic or acute back pain), and the influence of load was assessed. To evaluate methods of analysis of complex electromyogram data and to assess correlation of electromyogram information with clinical condition in people with and without back pain. In previous analyses of electromyogram data, only a small part of the data have been used. Spinal muscular decompensation has been postulated in chronic low back pain, but there has been no direct demonstration of this phenomenon. Objective measures are still elusive. Lumbar spinal surface electromyograms were recorded during an isometric lifting task. The data were represented graphically as color-coded plots of electromyogram frequency, time, and electromyogram amplitude. Spectral width at half-peak amplitude (spectral half width) was calculated from the digitized, summed data. Ninety-nine people were tested: 48 men (29 with no recent [in the past 2 years] history of back pain, 16 with chronic back pain, 3 with acute back pain) and 51 women (32 with no recent back pain and 19 with chronic back pain). Spectral color maps in people with chronic back pain were markedly different from those in healthy people. Spectral half width was greater in people with chronic back pain than in healthy people (P < 0.01). Blinded analysis of spectral color maps allowed discrimination of people with back pain from healthy people with a sensitivity of 76% and a specificity of 81%. People with a history of back pain had markedly variable half widths. A new method of analysis of electromyogram data from lumbar spinal muscles has allowed discrimination between people with back pain and healthy people. This provides direct evidence of a correlation between muscular electrical function, measured by electromyogram, and low back pain. This technique may have potential as an objective measurement tool.
Journal of Medicinal Chemistry, Mar 1, 2004
An LC/MS analysis with diagnostic screening for the detection of peptides with posttranslational ... more An LC/MS analysis with diagnostic screening for the detection of peptides with posttranslational modifications revealed the presence of novel sulfated peptides within the alpha-conotoxin molecular mass range in Conus anemone crude venom. A functional assay of the extract showed activity at several neuronal nicotinic acetylcholine receptors (nAChRs). Three sulfated alpha-conotoxins (AnIA, AnIB, and AnIC) were identified by LC/MS and assay-directed fractionation and sequenced after purification. The most active of these, alpha-AnIB, was further characterized and used to investigate the influence of posttranslational modifications on affinity. Synthetic AnIB exhibited subnanomolar potency at the rat alpha3beta2 nAChR (IC50 0.3 nM) and was 200-fold less active on the rat alpha7 nAChR (IC50 76 nM). The unsulfated peptide [Tyr16]AnIB showed a 2-fold and 10-fold decrease in activities at alpha3beta2 (IC50 0.6 nM) and alpha7 (IC50 836 nM) nAChR, respectively. Likewise, removal of the C-terminal amide had a greater influence on potency at the alpha7 (IC50 367 nM) than at the alpha3beta2 nAChR (IC50 0.5 nM). Stepwise removal of two N-terminal glycine residues revealed that these residues affect the binding kinetics of the peptide. Comparison with similar 4/7-alpha-conotoxin sequences suggests that residue 11 (alanine or glycine) and residue 14 (glutamine) constitute important determinants for alpha3beta2 selectivity, whereas the C-terminal amidation and sulfation at tyrosine-16 favor alpha7 affinity.
Journal of Inorganic Biochemistry, 2004
Patellamide D (patH(4)) is a cyclic octapeptide isolated from the ascidian Lissoclinum patella. T... more Patellamide D (patH(4)) is a cyclic octapeptide isolated from the ascidian Lissoclinum patella. The peptide possesses a 24-azacrown-8 macrocyclic structure containing two oxazoline and two thiazole rings, each separated by an amino acid. The present spectrophotometric, electron paramagnetic resonance (EPR) and mass spectral studies show that patellamide D reacts with CuCl(2) and triethylamine in acetonitrile to form mononuclear and binuclear copper(II) complexes containing chloride. Molecular modelling and EPR studies suggest that the chloride anion bridges the copper(II) ions in the binuclear complex [Cu(2)(patH(2))(mu-Cl)](+). These results contrast with a previous study employing both base and methanol, the latter substituting for chloride in the copper(II) complexes en route to the stable mu-carbonato binuclear copper(II) complex [Cu(2) (patH(2))(mu-CO(3))]. Solvent clearly plays an important role in both stabilising these metal ion complexes and influencing their chemical reactivities.
Archives of Toxicology, 2000
Acute exposure to naphthalene produces severe bronchiolar epithelial cell necrosis in mice, where... more Acute exposure to naphthalene produces severe bronchiolar epithelial cell necrosis in mice, whereas subchronic exposure to naphthalene (200 mg/kg/7 days) fails to produce epithelial necrosis and renders the animals tolerant to subsequent challenge doses of naphthalene. Mechanisms responsible for the development of tolerance have not been delineated. The few studies exploring naphthalene tolerance focus on expression of microsomal enzymes and have yet to delve into expression of the hepatic detoxification enzymes such as glutathione S-transferases (GSTs; EC 2.5.1.18). Glutathione conjugation catalyzed by GSTs accounts for one of the two primary routes of naphthalene detoxification. In this study, we rigorously quantify levels of individual GST isozymes expressed within the livers and lungs of mice with acquired tolerance to naphthalene. Subchronic exposure to naphthalene increases the abundance of some hepatic GSTs to levels as much as 68% greater than controls. Naphthalene-tolerant mice displayed increases in mGSTM1 (51%), mGSTM2 (58%), and mGSTP1 (66%), whereas no significant difference in mGSTA3 was observed between exposed and control mice. Extracts of pulmonary tissues from naphthalene-tolerant mice showed minor increases in levels of mGSTP1 (7%) and Peak 8 isozyme (27%) and decreases in levels of mGSTM1 (31%), mGSTM2 (17%), and mGSTA3 (8%). The total enzymatic activity for the conjugation of 1-chloro-2,4-dinitrobenzene (CDNB) was 22% lower in lung extracts from naphthalene-tolerant animals than in controls. These results indicate that induction of hepatic GSTs is substantial and may be an important factor in the development of tolerance to naphthalene.
The Chemical Engineering Journal and the Biochemical Engineering Journal, Aug 1, 1994
A comparison of methods proposed for the determination of crystallization kinetics from the cryst... more A comparison of methods proposed for the determination of crystallization kinetics from the crystal size distribution in continuous mixed-suspension, mixed-product-removal (MSMPR) crystallizers is presented for several systems exhibiting size-dependent crystal growth rates reported in the literature. Wide variations in inferred kinetic parameters are obtained depending on the analytical method adopted, leading to uncertainty in their utility. Direct fitting of differential population density data using exponential sizedependent growth models, however, gives an improved estimation of growth rates over the whole size range and leads to higher zero-size crystal growth and nucleation rates in comparison with other models tested.
Analytical Chemistry, Jul 1, 2008
Cross-linking can be used to identify spatial relationships between amino acids in proteins or pr... more Cross-linking can be used to identify spatial relationships between amino acids in proteins or protein complexes. A rapid and sensitive method for identifying the site of protein cross-linking using dithiobis(sulfosuccinimidyl propionate) (DTSSP) is presented and illustrated with experiments using murine cortactin, actin and acyl-CoA thioesterase. A characteristic 66 Da doublet, which arises from the asymmetric fragmentation of the disulfide of DTSSP-modified peptides, is observed in the mass spectra obtained under MALDI-TOF/TOF-MS conditions and allows rapid assignment of cross-links in modified proteins. This doublet is observed not only for linear cross-linked peptides but also in the mass spectra of cyclic cross-linked peptides when simultaneous fragmentation of the disulfide and the peptide backbone occurs. We suggest a likely mechanism for this fragmentation. We use guanidinylation of the cross-linked peptides with O-methyl isourea to extend the coverage of cross-linked peptides observed in this MALDI-MS technique. The methodology we report is robust and amenable to automation, and permits the analysis of native cystines along with those introduced by disulfide-containing cross-linkers. (1) Lundblad, R. L. Chemical reagents for protein modification, 3rd ed.; CRC Press: Boca Raton, FL, 2005. (2) Young, M. M.; Tang, N.; Hempel, J. C.; Oshiro, C. M.; Taylor, E. W.; Kuntz, I. D.; Gibson, B. W.; Dollinger, G. Proc. Natl. Acad. Sci. U.S.A. 2000, 97, 5802-5806. (3) Ihling, C.; Schmidt, A.; Kalkhof, S.; Schulz, D. M.; Stingl, C.; Mechtler, K.; Haack, M.; Beck-Sickinger, A. G.; Cooper, D. M.; Sinz, A. J. Am. Soc. Mass Spectrom. 2006, 17, 1100-1113. (4) Jacobsen, R. B.; Sale, K. L.; Ayson, M. J.; Novak, P.; Hong, J.; Lane, P.; Wood, N. L.; Kruppa, G. H.; Young, M. M.; Schoeniger, J. S. Protein Sci. 2006, 15, 1303-1317. (5) Mouradov, D.; Craven, A.; Forwood, J. K.; Flanagan, J. U.; Garcia-Castellanos, R.; Gomis-Ruth, F. X.; Hume, D. A.; Martin, J. L.; Kobe, B.; Huber, T. Robin, G.; Cowieson, N.; Forwood, J. K.; Listwan, P.; Hu, S. H.; Guncar, G.; Huber, T.; Kellie, S.; Hume, D. A.; Kobe, B.; Martin, J. L. Biomol Eng. 2006, 23, 281-289.
This section can introduce the researchers and provide an outline of the underpinning research. K... more This section can introduce the researchers and provide an outline of the underpinning research. Key contextual information such as timeframe, body of research, research project or programme along with the significance of this research in relation to the impact can be included.
European Urban and Regional Studies, 1995
concentrating 40 per cent of Czechoslovak vouchers in Kozeny’s hands. The government also feared ... more concentrating 40 per cent of Czechoslovak vouchers in Kozeny’s hands. The government also feared seeing so much economic power concentrated in the hands of people who granted Kozeny the finance and information needed for starting and maintaining his huge business. In 1994, after accusations of using secret police databases, Kozeny left for Switzerland. However, the crucial topics of mutual investment funds, influence in the Czech and Slovak economies, of insider dealing and of the origin of the capital needed for establishing such funds, remain unsolved. ’
Journal of Rural Studies, 1993
... The German government, in particular farm minister Ignaz Kiechle, is credited with convincing... more ... The German government, in particular farm minister Ignaz Kiechle, is credited with convincing other Community member states of the need for a set ... Case study 7 Surrounded by the forest of the Hunsruck lies the hamlet of Baldingen where Winfried H. described how his son had ...
Geopolitics, 2019
Where a licence is displayed above, please note the terms and conditions of the licence govern yo... more Where a licence is displayed above, please note the terms and conditions of the licence govern your use of this document. When citing, please reference the published version. Take down policy While the University of Birmingham exercises care and attention in making items available there are rare occasions when an item has been uploaded in error or has been deemed to be commercially or otherwise sensitive.
Geopolitics, 2011
The European Union (EU) is among the most prosperous, most developed and – by any conventional me... more The European Union (EU) is among the most prosperous, most developed and – by any conventional measure – potentially one of the most ‘powerful’ global actors of the twenty-first century. Nevertheless, there is a growing sense of incredulity among a widening range of policy actors, academics, political commentators and European publics over the seeming inability of the Union to present itself unambiguously and to act trenchantly on the international stage. Political scientists have furnished a number of explanations for the perceived international inadequacies of the EU. These centre upon the so-called capability-expectations gap in EU international action, arising from a combination of absence of political will and engagement among the Union’s constituent member states, clashes of historically conditioned national interests, insufficiencies in the EU’s foreign policy and security provisions, and/or weaknesses in the EU’s legal and decision-making structures. Other observers have preferred to see the EU as having its own particular form of international ‘actorness’ and ‘presence’ which creates a rather
Geoforum, 2013
1 cf. Berry's (2009, p. 393) recent comment on the lack of cross-disciplinary dialogue in his own... more 1 cf. Berry's (2009, p. 393) recent comment on the lack of cross-disciplinary dialogue in his own university: ''It was clear that most of the.. .political scientists were focused inward, on their own disciplinary concerns, by and for political scientists, and it was equally clear that political geographers had similarly territorialized world views and had been quite willing to push certain topics to the margins of that territory.''
European Urban and Regional Studies, 2013
In this paper we explore the current politico-economic tensions surrounding Iceland’s application... more In this paper we explore the current politico-economic tensions surrounding Iceland’s application for EU membership provoked by the state’s financial trauma of 2008. Through access to high level diplomats, politicians and EU Commission staff involved in preparing and negotiating Icelandic accession to the EU, we examine the difficulties for both sides of overcoming the country’s long-standing antipathy towards European political integration and appeasing the vociferous sectoral interests, especially in farming and fisheries, ranged against membership. The significance of this application far outstrips the size of this small island state since Iceland’s relationship with ‘EUrope’ is long-standing and complex. This national drama is given greater political salience as it is projected against the backdrop of ‘EUrope’s own existential struggles over the post-1945 political project of integration currently underway. Ultimately the saga of Iceland’s membership of the EU may be a relativel...
Environment and Planning D: Society and Space, 2011
Building on recent academic exchanges theorising sociospatial relations, we argue that it is not ... more Building on recent academic exchanges theorising sociospatial relations, we argue that it is not sociospatial concepts or metaphors per se that delineate the substance of such relations—rather it is the different politics by and through which these concepts are conceived, represented, and mobilised by elite actors. We make an empirically founded contribution to these exchanges by examining the context of the European Union's (EU) sociospatialities, illustrated specifically through central European elite activities in the wake of the 2004 accession to the EU. We show how central European elite assertions of sociospatial concepts were embroiled in complex ways with enactments of these sociospatialities—that is, how the assertion and performance of concepts such as space, territory, and positionality by elite actors created novel forms of politics which, subsequently, have become pivotal to the reconfiguration of contemporary EUropean space.
Tijdschrift voor economische en sociale geografie, 2016
Where a licence is displayed above, please note the terms and conditions of the licence govern yo... more Where a licence is displayed above, please note the terms and conditions of the licence govern your use of this document. When citing, please reference the published version. Take down policy While the University of Birmingham exercises care and attention in making items available there are rare occasions when an item has been uploaded in error or has been deemed to be commercially or otherwise sensitive.
Annals of the Association of American Geographers, 2009
The theory of "radical geopolitics" is directly concerned with identifying the roots of U.S. fore... more The theory of "radical geopolitics" is directly concerned with identifying the roots of U.S. foreign policy from a critical political economic perspective, seeking to determine the relative importance of political factors and economic forces in shaping foreign policy. It builds on Harvey's (2003) conceptualization of two logics of power and deploys a "geopolitical logic" and a "geoeconomic logic" to interpret political events. The former logic arises out of capitalism's tendency to expand geographically and the latter out of officials of statecraft's need to maintain their state's credibility internationally. Post-World War II U.S. foreign policy has largely followed the geoeconomic logic but has also been oriented (in sometimes divergent directions) by the geopolitical logic. A discussion of the Iranian nuclear "crisis" illustrates the radical geopolitics approach using national security documents outlining U.S. policy toward the Middle East and Iran, along with detailed interviews with senior diplomats from Iran, the United States, China, Russia, Germany, the United Kingdom, France, and the European Union. The Iranian crisis is a product of (1) American interest in the control of Iranian energy resources (a geoeconomic logic); and (2) American officials' need to reaffirm U.S. credibility in the face of Iranian defiance of U.S. hegemony in the Middle East (a geopolitical logic).
Transactions of the Institute of British Geographers
Since the mid-1990s much theoretical and empirical work in economic geography has been increasing... more Since the mid-1990s much theoretical and empirical work in economic geography has been increasingly focused upon a closer examination of the inter- meshing of the socio-spatial relations of actors with processes of economic change. This new focus in the sub-discipline has ...
Spine, 1998
A technique is described for analyzing electromyogram data from lumbar spinal muscles, with speci... more A technique is described for analyzing electromyogram data from lumbar spinal muscles, with special reference to discrimination of people with back pain. The ability to discriminate was evaluated in 99 people (61 healthy and 38 with chronic or acute back pain), and the influence of load was assessed. To evaluate methods of analysis of complex electromyogram data and to assess correlation of electromyogram information with clinical condition in people with and without back pain. In previous analyses of electromyogram data, only a small part of the data have been used. Spinal muscular decompensation has been postulated in chronic low back pain, but there has been no direct demonstration of this phenomenon. Objective measures are still elusive. Lumbar spinal surface electromyograms were recorded during an isometric lifting task. The data were represented graphically as color-coded plots of electromyogram frequency, time, and electromyogram amplitude. Spectral width at half-peak amplitude (spectral half width) was calculated from the digitized, summed data. Ninety-nine people were tested: 48 men (29 with no recent [in the past 2 years] history of back pain, 16 with chronic back pain, 3 with acute back pain) and 51 women (32 with no recent back pain and 19 with chronic back pain). Spectral color maps in people with chronic back pain were markedly different from those in healthy people. Spectral half width was greater in people with chronic back pain than in healthy people (P < 0.01). Blinded analysis of spectral color maps allowed discrimination of people with back pain from healthy people with a sensitivity of 76% and a specificity of 81%. People with a history of back pain had markedly variable half widths. A new method of analysis of electromyogram data from lumbar spinal muscles has allowed discrimination between people with back pain and healthy people. This provides direct evidence of a correlation between muscular electrical function, measured by electromyogram, and low back pain. This technique may have potential as an objective measurement tool.
Journal of Medicinal Chemistry, Mar 1, 2004
An LC/MS analysis with diagnostic screening for the detection of peptides with posttranslational ... more An LC/MS analysis with diagnostic screening for the detection of peptides with posttranslational modifications revealed the presence of novel sulfated peptides within the alpha-conotoxin molecular mass range in Conus anemone crude venom. A functional assay of the extract showed activity at several neuronal nicotinic acetylcholine receptors (nAChRs). Three sulfated alpha-conotoxins (AnIA, AnIB, and AnIC) were identified by LC/MS and assay-directed fractionation and sequenced after purification. The most active of these, alpha-AnIB, was further characterized and used to investigate the influence of posttranslational modifications on affinity. Synthetic AnIB exhibited subnanomolar potency at the rat alpha3beta2 nAChR (IC50 0.3 nM) and was 200-fold less active on the rat alpha7 nAChR (IC50 76 nM). The unsulfated peptide [Tyr16]AnIB showed a 2-fold and 10-fold decrease in activities at alpha3beta2 (IC50 0.6 nM) and alpha7 (IC50 836 nM) nAChR, respectively. Likewise, removal of the C-terminal amide had a greater influence on potency at the alpha7 (IC50 367 nM) than at the alpha3beta2 nAChR (IC50 0.5 nM). Stepwise removal of two N-terminal glycine residues revealed that these residues affect the binding kinetics of the peptide. Comparison with similar 4/7-alpha-conotoxin sequences suggests that residue 11 (alanine or glycine) and residue 14 (glutamine) constitute important determinants for alpha3beta2 selectivity, whereas the C-terminal amidation and sulfation at tyrosine-16 favor alpha7 affinity.
Journal of Inorganic Biochemistry, 2004
Patellamide D (patH(4)) is a cyclic octapeptide isolated from the ascidian Lissoclinum patella. T... more Patellamide D (patH(4)) is a cyclic octapeptide isolated from the ascidian Lissoclinum patella. The peptide possesses a 24-azacrown-8 macrocyclic structure containing two oxazoline and two thiazole rings, each separated by an amino acid. The present spectrophotometric, electron paramagnetic resonance (EPR) and mass spectral studies show that patellamide D reacts with CuCl(2) and triethylamine in acetonitrile to form mononuclear and binuclear copper(II) complexes containing chloride. Molecular modelling and EPR studies suggest that the chloride anion bridges the copper(II) ions in the binuclear complex [Cu(2)(patH(2))(mu-Cl)](+). These results contrast with a previous study employing both base and methanol, the latter substituting for chloride in the copper(II) complexes en route to the stable mu-carbonato binuclear copper(II) complex [Cu(2) (patH(2))(mu-CO(3))]. Solvent clearly plays an important role in both stabilising these metal ion complexes and influencing their chemical reactivities.
Archives of Toxicology, 2000
Acute exposure to naphthalene produces severe bronchiolar epithelial cell necrosis in mice, where... more Acute exposure to naphthalene produces severe bronchiolar epithelial cell necrosis in mice, whereas subchronic exposure to naphthalene (200 mg/kg/7 days) fails to produce epithelial necrosis and renders the animals tolerant to subsequent challenge doses of naphthalene. Mechanisms responsible for the development of tolerance have not been delineated. The few studies exploring naphthalene tolerance focus on expression of microsomal enzymes and have yet to delve into expression of the hepatic detoxification enzymes such as glutathione S-transferases (GSTs; EC 2.5.1.18). Glutathione conjugation catalyzed by GSTs accounts for one of the two primary routes of naphthalene detoxification. In this study, we rigorously quantify levels of individual GST isozymes expressed within the livers and lungs of mice with acquired tolerance to naphthalene. Subchronic exposure to naphthalene increases the abundance of some hepatic GSTs to levels as much as 68% greater than controls. Naphthalene-tolerant mice displayed increases in mGSTM1 (51%), mGSTM2 (58%), and mGSTP1 (66%), whereas no significant difference in mGSTA3 was observed between exposed and control mice. Extracts of pulmonary tissues from naphthalene-tolerant mice showed minor increases in levels of mGSTP1 (7%) and Peak 8 isozyme (27%) and decreases in levels of mGSTM1 (31%), mGSTM2 (17%), and mGSTA3 (8%). The total enzymatic activity for the conjugation of 1-chloro-2,4-dinitrobenzene (CDNB) was 22% lower in lung extracts from naphthalene-tolerant animals than in controls. These results indicate that induction of hepatic GSTs is substantial and may be an important factor in the development of tolerance to naphthalene.
The Chemical Engineering Journal and the Biochemical Engineering Journal, Aug 1, 1994
A comparison of methods proposed for the determination of crystallization kinetics from the cryst... more A comparison of methods proposed for the determination of crystallization kinetics from the crystal size distribution in continuous mixed-suspension, mixed-product-removal (MSMPR) crystallizers is presented for several systems exhibiting size-dependent crystal growth rates reported in the literature. Wide variations in inferred kinetic parameters are obtained depending on the analytical method adopted, leading to uncertainty in their utility. Direct fitting of differential population density data using exponential sizedependent growth models, however, gives an improved estimation of growth rates over the whole size range and leads to higher zero-size crystal growth and nucleation rates in comparison with other models tested.
Analytical Chemistry, Jul 1, 2008
Cross-linking can be used to identify spatial relationships between amino acids in proteins or pr... more Cross-linking can be used to identify spatial relationships between amino acids in proteins or protein complexes. A rapid and sensitive method for identifying the site of protein cross-linking using dithiobis(sulfosuccinimidyl propionate) (DTSSP) is presented and illustrated with experiments using murine cortactin, actin and acyl-CoA thioesterase. A characteristic 66 Da doublet, which arises from the asymmetric fragmentation of the disulfide of DTSSP-modified peptides, is observed in the mass spectra obtained under MALDI-TOF/TOF-MS conditions and allows rapid assignment of cross-links in modified proteins. This doublet is observed not only for linear cross-linked peptides but also in the mass spectra of cyclic cross-linked peptides when simultaneous fragmentation of the disulfide and the peptide backbone occurs. We suggest a likely mechanism for this fragmentation. We use guanidinylation of the cross-linked peptides with O-methyl isourea to extend the coverage of cross-linked peptides observed in this MALDI-MS technique. The methodology we report is robust and amenable to automation, and permits the analysis of native cystines along with those introduced by disulfide-containing cross-linkers. (1) Lundblad, R. L. Chemical reagents for protein modification, 3rd ed.; CRC Press: Boca Raton, FL, 2005. (2) Young, M. M.; Tang, N.; Hempel, J. C.; Oshiro, C. M.; Taylor, E. W.; Kuntz, I. D.; Gibson, B. W.; Dollinger, G. Proc. Natl. Acad. Sci. U.S.A. 2000, 97, 5802-5806. (3) Ihling, C.; Schmidt, A.; Kalkhof, S.; Schulz, D. M.; Stingl, C.; Mechtler, K.; Haack, M.; Beck-Sickinger, A. G.; Cooper, D. M.; Sinz, A. J. Am. Soc. Mass Spectrom. 2006, 17, 1100-1113. (4) Jacobsen, R. B.; Sale, K. L.; Ayson, M. J.; Novak, P.; Hong, J.; Lane, P.; Wood, N. L.; Kruppa, G. H.; Young, M. M.; Schoeniger, J. S. Protein Sci. 2006, 15, 1303-1317. (5) Mouradov, D.; Craven, A.; Forwood, J. K.; Flanagan, J. U.; Garcia-Castellanos, R.; Gomis-Ruth, F. X.; Hume, D. A.; Martin, J. L.; Kobe, B.; Huber, T. Robin, G.; Cowieson, N.; Forwood, J. K.; Listwan, P.; Hu, S. H.; Guncar, G.; Huber, T.; Kellie, S.; Hume, D. A.; Kobe, B.; Martin, J. L. Biomol Eng. 2006, 23, 281-289.