1
|
Chen PC, Kutzki F, Mojzisch A, Simon B, Xu ER, Aponte-Santamaría C, Horny K, Jeffries C, Schneppenheim R, Wilmanns M, Brehm MA, Gräter F, Hennig J. Structure and dynamics of the von Willebrand Factor C6 domain. J Struct Biol 2022; 214:107923. [PMID: 36410652 DOI: 10.1016/j.jsb.2022.107923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 11/08/2022] [Accepted: 11/12/2022] [Indexed: 11/19/2022]
Abstract
Von Willebrand disease (VWD) is a bleeding disorder with different levels of severity. VWD-associated mutations are located in the von Willebrand factor (VWF) gene, coding for the large multidomain plasma protein VWF with essential roles in hemostasis and thrombosis. On the one hand, a variety of mutations in the C-domains of VWF are associated with increased bleeding upon vascular injury. On the other hand, VWF gain-of-function (GOF) mutations in the C4 domain have recently been identified, which induce an increased risk of myocardial infarction. Mechanistic insights into how these mutations affect the molecular behavior of VWF are scarce and holistic approaches are challenging due to the multidomain and multimeric character of this large protein. Here, we determine the structure and dynamics of the C6 domain and the single nucleotide polymorphism (SNP) variant G2705R in C6 by combining nuclear magnetic resonance spectroscopy, molecular dynamics simulations and aggregometry. Our findings indicate that this mutation mostly destabilizes VWF by leading to a more pronounced hinging between both subdomains of C6. Hemostatic parameters of variant G2705R are close to normal under static conditions, but the missense mutation results in a gain-of-function under flow conditions, due to decreased VWF stem stability. Together with the fact that two C4 variants also exhibit GOF characteristics, our data underline the importance of the VWF stem region in VWF's hemostatic activity and the risk of mutation-associated prothrombotic properties in VWF C-domain variants due to altered stem dynamics.
Collapse
Affiliation(s)
- Po-Chia Chen
- Structural and Computational Biology Unit, EMBL Heidelberg, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Fabian Kutzki
- Heidelberg Institute for Theoretical Studies, Schloss-Wolfsbrunnenweg 35, 69118 Heidelberg, Germany
| | - Angelika Mojzisch
- Dermatology and Venereology, University Medical Centre Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
| | - Bernd Simon
- Structural and Computational Biology Unit, EMBL Heidelberg, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Emma-Ruoqi Xu
- European Molecular Biology Laboratory, Hamburg Unit, Notkestraße 85, 22607 Hamburg, Germany
| | - Camilo Aponte-Santamaría
- Heidelberg Institute for Theoretical Studies, Schloss-Wolfsbrunnenweg 35, 69118 Heidelberg, Germany
| | - Kai Horny
- Structural and Computational Biology Unit, EMBL Heidelberg, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Cy Jeffries
- European Molecular Biology Laboratory, Hamburg Unit, Notkestraße 85, 22607 Hamburg, Germany
| | - Reinhard Schneppenheim
- Pediatric Hematology and Oncology, University Medical Centre Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
| | - Matthias Wilmanns
- European Molecular Biology Laboratory, Hamburg Unit, Notkestraße 85, 22607 Hamburg, Germany; University Medical Centre Hamburg-Eppendorf, Martinistraße 52, 20246 Hamburg, Germany
| | - Maria A Brehm
- Department of Digital Health Sciences and Biomedicine, School of Life Sciences, University of Siegen, Am Eichenhang 50, 57076 Siegen, Germany
| | - Frauke Gräter
- Heidelberg Institute for Theoretical Studies, Schloss-Wolfsbrunnenweg 35, 69118 Heidelberg, Germany; Interdisciplinary Center for Scientific Computing, Heidelberg University, INF 305, 69120 Heidelberg, Germany.
| | - Janosch Hennig
- Structural and Computational Biology Unit, EMBL Heidelberg, Meyerhofstrasse 1, 69117 Heidelberg, Germany; Chair of Biochemistry IV, Biophysical Chemistry, University of Bayreuth, 95447 Bayreuth, Germany.
| |
Collapse
|
2
|
Gruzinov A, Schroer M, Blanchet C, Manalastas-Cantos K, Kikhney A, Hajizadeh N, Wieland F, Schulz F, Franke D, Jeffries C, Svergun D. Anomalous small-angle X-ray scattering on biological macromolecules at the P12 beamline of EMBL-Hamburg. Acta Crystallogr A Found Adv 2021. [DOI: 10.1107/s0108767321093922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
|
3
|
Jhaveri U, Jeffries C, Ranjan S, Latona J, Jesuthasan B, Challa P, Dahiya A. Integration of Contemporary CT Coronary Angiography in Care of Patients Suspected to have Takotsubo Cardiomyopathy. Heart Lung Circ 2019. [DOI: 10.1016/j.hlc.2019.06.284] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
4
|
Gounden S, Reyaldeen R, Jeffries C, Jesuthasan B, Ranjan S, Challa P, Dahiya A. The Diagnostic Performance of Computed Tomography Coronary Angiography in Patients Above the Age of 65 Years Versus Those Under 65 Years of Age. Heart Lung Circ 2018. [DOI: 10.1016/j.hlc.2018.06.522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
5
|
Shah NS, Flood-Bryzman A, Jeffries C, Scott J. Toward a generation free of tuberculosis: TB disease and infection in individuals of college age in the United States. J Am Coll Health 2018; 66:17-22. [PMID: 28800282 PMCID: PMC9394587 DOI: 10.1080/07448481.2017.1363765] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
OBJECTIVES To assess the magnitude of active TB disease and latent TB infection (LTBI) in young adults of college age. PARTICIPANTS Individuals who were aged 18-24 years in 2011 were used as a proxy for college students. METHODS Active TB cases reported to the 2011 US National TB Surveillance System (NTSS) were included. LTBI prevalence was calculated from the 2011-2012 National Health and Nutrition Examination Survey. The 2011 American Community Survey was used to calculate population denominators. Analyses were stratified by nativity. RESULTS Active TB disease incidence among persons aged 18-24 years was 2.82/100,000, 18.8/100,000 among foreign-born individuals and 0.9/100,000 among US-born individuals. In 2011, 878 TB cases were reported; 629 (71.6%) were foreign-born. LTBI prevalence among persons of 18-24 years was 2.5%: 8.7% and 1.3% among foreign-born and US-born, respectively. CONCLUSION Active screening and treatment programs for foreign-born young adults could identify TB cases earlier and provide an opportunity for prevention efforts.
Collapse
Affiliation(s)
- N. S. Shah
- National Center for HIV/AIDS, Hepatitis, STD and TB Prevention, Division of TB Elimination, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | | | - C. Jeffries
- National Center for HIV/AIDS, Hepatitis, STD and TB Prevention, Division of TB Elimination, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - J. Scott
- Department of Mathematics & Statistics, Colby College, Waterville, Maine, USA
| |
Collapse
|
6
|
Blanchet CE, Schroer MA, Jeffries C, Gruzinov AY, Graewert MA, Hajizadeh NR, Svergun DI. Study and mitigation of radiation damage on the P12 BioSAXS beamline. Acta Crystallogr A Found Adv 2017. [DOI: 10.1107/s2053273317085485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023] Open
|
7
|
Reyaldeen R, Gounden S, Jeffries C, Jesuthasan B, Ranjan S, Challa P, Dahiya A. Impact of Age, Gender and Cardiac Risk Factors on Diagnostic Ability of Low Radiation CTCA in Patients Above the Age of 65 Years. Heart Lung Circ 2017. [DOI: 10.1016/j.hlc.2017.06.506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
8
|
Hamilton J, Garces Bovett C, Harris C, Jeffries C, Jones T. FRI0629-HPR Back To Action: A Guide To Exercising Safely in The Gym with Ankylosing Spondylitis - Book and App User Perspectives. Ann Rheum Dis 2016. [DOI: 10.1136/annrheumdis-2016-eular.1194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
9
|
Longford E, Scott A, Fradsham S, Jeffries C, Ahmad F, Holland G, Telfer R, Carlson J, Ferguson H. MALIGNANT BOWEL OBSTRUCTION—A SYSTEMATIC LITERATURE REVIEW AND EVALUATION OF CURRENT PRACTICE. BMJ Support Palliat Care 2015. [DOI: 10.1136/bmjspcare-2014-000838.44] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
10
|
Binny S, Dahiya A, Challa P, Hardman D, Jeffries C. The fat scan study: correlation of visceral adipose tissue to coronary atherosclerosis in a multi-ethnicity Australian population. Heart Lung Circ 2015. [DOI: 10.1016/j.hlc.2015.06.135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
11
|
Jacques D, Jeffries C, Caines M, Lammers M, Mallery D, Price A, McLaughlin S, Johnson C, Svergun D, James L. TRIM protein domain topology and implications for antiviral immunity. Acta Crystallogr A Found Adv 2014. [DOI: 10.1107/s2053273314097563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The tripartite motif (TRIM) proteins are a large family of >100 members, several of which have important roles in antiviral immunity and innate immune signaling. TRIM5α associates with incoming HIV-1 capsids, interfering with controlled disassembly and targeting them for degradation by the proteasome. TRIM21 is a cytosolic antibody receptor, which also targets incoming viral capsids for proteasomal degradation. TRIM25 is also involved in innate immunity, being essential for the ubiquitination of RIG-I. Recent positive selection analysis has predicted another 10 TRIM proteins with antiviral activity. Despite the fact that TRIM5α, 21 and 25 play key roles in antiviral protection, their mechanism of action is incompletely understood. All three proteins share a similar domain architecture, comprising a RING, B Box, coiled coil and PRYSPRY domains. The RING domains are responsible for ubiquitin ligase activity, while the PRYSPRY domains determine target specificity. We have used a combination of crystallography and SAXS to generate the first complete model for a TRIM protein structure. Crystallographic studies of TRIM25 reveal a central elongated coiled-coil domain with an unusual right-handed twist. The dimer formed by the coiled-coil is antiparallel but is followed by additional helices that reverse the direction of the protein chain. This structure suggests that the N-terminal domains of each monomer are separated but the C terminal domains are maintained in proximity. Multi-angle light scattering (MALS), isothermal titration calorimetry (ITC) and SAXS analysis confirms that this dimer structure is present in solution. Furthermore, scattering studies on the tripartite motif of TRIM21, comprising RING, B Box and coiled-coil, demonstrate that the first two domains of each monomer are held 150-200 Å apart. Finally, SAXS measurement of a complex between intact TRIM21 and its ligand, IgG Fc, provides the first empirical structure of a complete TRIM protein.
Collapse
|
12
|
McGonagle D, McKenna F, Maher T, Kavanagh R, Cunningham AM, Lee M, Grosart R, Wakefield R, Kane D, Schmidt W, Young T, Ndosi M, Lewis M, Hale C, Bird H, Ryan S, Quinn H, McIvor E, Taylor J, Burbage G, Bond D, White J, Chagadama D, Green S, Kay L, Pace AV, Bejarano V, Emery P, Hill J, Hurley M, Porcheret M, Hart O, Oliver D, Coates L, Backhouse M, Coates L, Pickles D, Chamberlain V, Partridge K, Pickles D, Keat A, Maddison P, Taylor P, Dillon A, Chapman V, Pincus T, Shelton D, Ballestar E, Loughlin J, Tak PP, Prinjha R, Regan L, D'Cruz D, Jones G, Lewis J, den Hollander M, Goossens M, de Jong J, Smeets R, Vlaeyen J, Ioannou J, McDonagh J, Clinch J, Pilkington C, Siebert S, Martindale J, Beevor C, Jeffries C, Deighton C, Nye A, Cook D, Taylor P, Firth J, Pickles D, Chamberlain V, Taylor P, Emery P. Essentials in Rheumatology: Disease Management * I29. Recognition and Management of the Auto-Inflammatory Diseases. Rheumatology (Oxford) 2013. [DOI: 10.1093/rheumatology/ket194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
13
|
Horton DL, Lawson B, Egbetade A, Jeffries C, Johnson N, Cunningham AA, Fooks AR. Targeted surveillance for Usutu virus in British birds (2005-2011). Vet Rec 2012. [PMID: 23193038 DOI: 10.1136/vr.101275] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
- D L Horton
- Department of Virology, Animal Health and Veterinary Laboratories Agency AHVLA, Addlestone, Surrey, UK.
| | | | | | | | | | | | | |
Collapse
|
14
|
Mokbel N, Ilkovski B, Memo M, Marttila M, Kreissl M, Wallgren-Pettersson C, Menard D, Marcorelles P, Echaniz-Laguna A, Reimann J, Vainzof M, Monnier N, Nowak K, McNamara E, Laing N, Trewhella J, Jeffries C, Ottenheijm C, North K, Clarke N. C.P.15 K7del is a recurrent TPM2 nemaline myopathy mutation associated with joint contractures and increased calcium sensitivity. Neuromuscul Disord 2012. [DOI: 10.1016/j.nmd.2012.06.143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
15
|
|
16
|
Chow J, Claridge J, Jeffries C, Headley S, Soares G, Schwalbe M, Pascal S, Trewhella J. The interaction between human rhinovirus 3C protease and stem loop D studied by solution scattering. Acta Crystallogr A 2008. [DOI: 10.1107/s0108767308093136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
|
17
|
Perkins DO, Jeffries C, Sullivan P. Expanding the 'central dogma': the regulatory role of nonprotein coding genes and implications for the genetic liability to schizophrenia. Mol Psychiatry 2005; 10:69-78. [PMID: 15381925 DOI: 10.1038/sj.mp.4001577] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
It is now evident that nonprotein coding RNA (ncRNA) plays a critical role in regulating the timing and rate of protein translation. The potential importance of ncRNAs is suggested by the observation that the complexity of an organism is poorly correlated with its number of protein coding genes, yet highly correlated with its number of ncRNA genes, and that in the human genome only a small fraction (2-3%) of genetic transcripts are actually translated into proteins. In this review, we discuss several examples of known RNA mechanisms for the regulation of protein synthesis. We then discuss the possibility that ncRNA regulation of schizophrenia risk genes may underlie the diverse findings of genetic linkage studies including that protein-altering gene polymorphisms are not generally found in schizophrenia. Thus, inadequate or mistimed expression of a functional protein may occur either due to mutation or other dysfunction of the DNA coding base pair sequence, leading to a dysfunctional protein, or due to post-transcriptional events such as abnormal ncRNA regulation of a normal gene. One or more 'schizophrenia disease genes' may turn out to include abnormal transcriptional units that code for RNA regulators of protein coding gene expression or to be proximal to such units, rather than to be abnormalities in the protein coding gene itself. Understanding the genetics of schizophrenia and other complex neuropsychiatric disorders might very well include consideration of RNA and epigenetic regulation of protein expression in addition to polymorphisms of the protein coding gene.
Collapse
Affiliation(s)
- D O Perkins
- Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
| | | | | |
Collapse
|
18
|
Pasco N, Baronian K, Jeffries C, Webber J, Hay J. MICREDOX®—development of a ferricyanide-mediated rapid biochemical oxygen demand method using an immobilised Proteus vulgaris biocomponent. Biosens Bioelectron 2004; 20:524-32. [PMID: 15494235 DOI: 10.1016/j.bios.2004.02.016] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2003] [Revised: 02/22/2004] [Accepted: 02/25/2004] [Indexed: 11/23/2022]
Abstract
Biochemical oxygen demand (BOD) is an international regulatory environmental index for monitoring organic pollutants in wastewater and the current legislated standard test for BOD monitoring requires 5 days to complete (BOD5 test). We are developing a rapid microbial technique, MICREDOX, for measuring BOD by eliminating oxygen and, instead, quantifying an equivalent biochemical co-substrate demand, the co-substrate being a redox mediator. Elevated concentrations of Proteus vulgaris, either as free cells or immobilised in Lentikat disks, were incubated with an excess of redox mediator (potassium hexacyanoferrate(III)) and organic substrate for 1h at 37 degrees C without oxygen. The addition of substrate increased the catabolic activity of the microorganisms and the accumulation of reduced mediator, which was subsequently re-oxidised at a working electrode generating a current quantifiable by a coulometric transducer. The recorded currents were converted to their BOD5 equivalent with the only assumption being a fixed conversion of substrate and known stoichiometry. Measurements are reported both for the BOD5 calibration standard solution (150 mg l(-1) glucose, 150 mg l(-1) glutamic acid) and for filtered effluent sampled from a wastewater treatment plant. The inclusion of a highly soluble mediator in place of oxygen facilitated a high ferricyanide concentration in the incubation, which in turn permitted increased concentrations of microorganisms to be used. This substantially reduced the incubation time, from 5 days to 1h, for the biological oxidation of substrates equivalent to those observed using the standard BOD5 test. Stoichiometric conversion efficiencies for the oxidation of the standard substrate by P. vulgaris were typically 60% for free cells and 35-50% for immobilised cells.
Collapse
Affiliation(s)
- Neil Pasco
- Lincoln Technology, Lincoln Ventures Ltd., P.O. Box 133, Lincoln, Christchurch 8152, New Zealand.
| | | | | | | | | |
Collapse
|
19
|
Jeffries C. Getting the pharmacist involved. Health Aff (Millwood) 2000; 19:278-9. [PMID: 10916985 DOI: 10.1377/hlthaff.19.4.278-a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
20
|
Pasco N, Baronian K, Jeffries C, Hay J. Biochemical mediator demand--a novel rapid alternative for measuring biochemical oxygen demand. Appl Microbiol Biotechnol 2000; 53:613-8. [PMID: 10855725 DOI: 10.1007/s002530051666] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The biochemical oxygen demand (BOD) test (BOD5) is a crucial environmental index for monitoring organic pollutants in waste water but is limited by the 5-day requirement for completing the test. We have optimised a rapid microbial technique for measuring the BOD of a standard BOD5 substrate (150 mg glucose/l, 150 mg glutamic acid/l) by quantifying an equivalent biochemical mediator demand in the absence of oxygen. Elevated concentrations of Escherichia coli were incubated with an excess of redox mediator, potassium hexacyanoferrate(III), and a known substrate for 1 h at 37 degrees C without oxygen. The addition of substrate increased the respiratory activity of the microorganisms and the accumulation of reduced mediator; the mediator was subsequently re-oxidised at a working electrode generating a current quantifiable by a coulometric transducer. Catabolic conversion efficiencies exceeding 75% were observed for the oxidation of the standard substrate. The inclusion of a mediator allowed a higher co-substrate concentration compared to oxygen and substantially reduced the incubation time from 5 days to 1 h. The technique replicates the traditional BOD5 method, except that a mediator is substituted for oxygen, and we aim to apply the principle to measure the BOD of real waste streams in future work.
Collapse
Affiliation(s)
- N Pasco
- Lincoln Technology, Lincoln Ventures Ltd, Lincoln University, Canterbury, New Zealand.
| | | | | | | |
Collapse
|
21
|
Abstract
alpha/beta Hydrolase fold proteins are an important, diverse, widespread group of enzymes not yet fully exploited by structural biologists. We describe the current state of knowledge of this family, and suggest a smaller definition of the required core and some possible future avenues of exploration.
Collapse
|
22
|
Pasco N, Jeffries C, Davies Q, Downard AJ, Roddick-Lanzilotta AD, Gorton L. Characterisation of a thermophilic L-glutamate dehydrogenase biosensor for amperometric determination of L-glutamate by flow injection analysis. Biosens Bioelectron 1999; 14:171-8. [PMID: 10101839 DOI: 10.1016/s0956-5663(98)00120-1] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Carbon paste wax electrodes incorporating thermophilic L-glutamate dehydrogenase, NADP and a polymeric toluidine blue O (poly-TBO) mediator have been characterised for the amperometric determination of L-glutamate at 313-318 K in a flow injection analysis (FIA) system. The biosensors exhibit good sensitivity, mechanical stability and reproducibilty, unlike carbon paste- or carbon wax-based electrodes under the same conditions. The carbon paste wax electrode responds linearly to L-glutamate up to 40 mM, the detection limit is 0.3 mM and the RSD (n = 10) for 5 mM L-glutamate was 7.6%. The response to some potential interferents has been quantified. Addition of finely ground hexaammineruthenium (III) trichloride ([Ru(NH3)6]Cl3) to the carbon paste wax electrodes decreases the FIA peak width and increases the peak current. The metal complex appears to accelerate the rate of oxidation of NAD(P)H by poly-TBO.
Collapse
Affiliation(s)
- N Pasco
- Lincoln Technology, Lincoln Ventures Limited, Lincoln University, Canterbury, New Zealand
| | | | | | | | | | | |
Collapse
|
23
|
Chen L, Carpita NC, Reiter WD, Wilson RH, Jeffries C, McCann MC. A rapid method to screen for cell-wall mutants using discriminant analysis of Fourier transform infrared spectra. Plant J 1998; 16:385-92. [PMID: 9881159 DOI: 10.1046/j.1365-313x.1998.00301.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
We have developed a rapid method to screen large numbers of mutant plants for a broad range of cell wall phenotypes using Fourier transform infrared (FTIR) microspectroscopy of leaves. We established and validated a model that can discriminate between the leaves of wild-type and a previously defined set of cell-wall mutants of Arabidopsis. Exploratory principal component analysis indicated that mutants deficient in different cell-wall sugars can be distinguished from each other. Discrimination of cell-wall mutants from wild-type was independent of variability in starch content or additional unrelated mutations that might be present in a heavily mutagenised population. We then developed an analysis of FTIR spectra of leaves obtained from over 1000 mutagenised flax plants, and selected 59 plants whose spectral variation from wild-type was significantly out of the range of a wild-type population, determined by Mahalanobis distance. Cell wall sugars from the leaves of selected putative mutants were assayed by gas chromatography-mass spectrometry and 42 showed significant differences in neutral sugar composition. The FTIR spectra indicated that six of the remaining 17 plants have altered ester or protein content. We conclude that linear discriminant analysis of FTIR spectra is a robust method to identify a broad range of structural and architectural alterations in cell walls, appearing as a consequence of developmental regulation, environmental adaptation or genetic modification.
Collapse
Affiliation(s)
- L Chen
- School of Physics, University of East Anglia, Norwich, UK
| | | | | | | | | | | |
Collapse
|
24
|
Affiliation(s)
- L A O'Neill
- Dept. of Biochemistry, Trinity College Dublin, Ireland
| | | | | | | | | | | |
Collapse
|
25
|
Jeffries C, Pasco N, Baronian K, Gorton L. Evaluation of a thermophile enzyme for a carbon paste amperometric biosensor: L-glutamate dehydrogenase. Biosens Bioelectron 1997. [DOI: 10.1016/s0956-5663(97)85340-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
26
|
Stephenson PR, Jeffries C. A financial survey of home medical equipment dealers. Caring 1991; 10:14-7. [PMID: 10114899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
The Health Industry Distributors Association's ninth annual survey of home medical equipment dealers allows firms to compare their performance to industry averages, enabling managers to identify those specific aspects of company performance that demand their attention.
Collapse
Affiliation(s)
- P R Stephenson
- Graduate School of Business, Indiana University, Bloomington
| | | |
Collapse
|
27
|
Jeffries C, Lam QH, Kim Y, Bourne LC, Zettl A. Symmetry breaking and nonlinear electrodynamics in the ceramic superconductor YBa2Cu3O7. Phys Rev B Condens Matter 1988; 37:9840-9843. [PMID: 9944396 DOI: 10.1103/physrevb.37.9840] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
|
28
|
|
29
|
Held GA, Jeffries C. Quasiperiodic transitions to chaos of instabilities in an electron-hole plasma excited by ac perturbations at one and at two frequencies. Phys Rev Lett 1986; 56:1183-1186. [PMID: 10032591 DOI: 10.1103/physrevlett.56.1183] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
|
30
|
Held GA, Jeffries C. Spatial and temporal structure of chaotic instabilities in an electron-hole plasma in Ge. Phys Rev Lett 1985; 55:887-890. [PMID: 10032473 DOI: 10.1103/physrevlett.55.887] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
|
31
|
Jeffries C, Schiefer HB. Potential consequences of a fire in an insecticide storage facility. Regul Toxicol Pharmacol 1985; 5:197-203. [PMID: 4023290 DOI: 10.1016/0273-2300(85)90033-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Assumptions are identified and made in an attempt to model the acute human health risk associated with a hypothetical fire in an insecticide storage facility. The insecticides used in the model are endrin and dimethoate. The model indicates that persons residing a few hundred meters from the facility could suffer a variety of adverse effects, including possible death from contact with smoke from a prolonged, low-temperature fire. Knowledge of the special hazards of cool toxic smoke as well as current atmospheric conditions could be of use to fire fighters. That is, fire fighters might wisely choose to promote a fast, hot fire which would propel toxicants high into the atmosphere rather than risk local fumigation.
Collapse
|
32
|
|
33
|
|
34
|
Hall GH, Jeffries C. The contribution of nitrification in the water column and profundal sediments to the total oxygen deficit of the hypolimnion of a mesotrophic lake (Grasmere, English Lake District). Microb Ecol 1984; 10:37-46. [PMID: 24221048 DOI: 10.1007/bf02011593] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Estimates ofin situ nitrifying activity have been made in the hypolimnetic water column and surface 1.0 cm of profundal sediments at 2 sites in Grasmere, a mesotrophic lake in the English Lake District. Increases of nitrate concentrations were used to estimate nitrification in the water column whereas a mini-core technique, involving the use of a nitrification inhibitor (allylthiourea), was used to estimate the rate in surface sediments. The pattern of oxygen depletion in the water column was used to estimate the maximum depth to which sediments affect the overlying water. Nitrification in the sediment and in the water column made approximately equal contributions to the total areal oxygen deficit and, as a whole, nitrification accounted for 15-20% of the total oxygen depletion. There was no significant difference in oxygen depletion due to nitrification between the 2 sites. Attempts were made, using the nitrification potential technique, to determine the depth distribution of nitrifying activity in the surface 1.0 cm of sediment.
Collapse
Affiliation(s)
- G H Hall
- Freshwater Biological Association, The Ferry House, Far Sawrey, Ambleside, Cumbria, UK
| | | |
Collapse
|
35
|
Abstract
The temperature of the isolation medium exerted no significant effect on the rate of positive cultures for Neisseria gonorrhoeae. However, significantly more colonies were obtained on ambient-temperature medium than on cold (4C) medium. A small number of specimens (six) failed to grow on cold medium but grew on ambient-temperature medium. Viable counts showed essentially no effect of medium temperature on the nondiscriminating strain, a 90% reduction on the cold medium for the cold-intolerant strain, and for the strains with warm medium preference, about twice as many colonies on warm as on cold or ambient-temperature medium.
Collapse
|
36
|
Abstract
The penile ulcerations of 100 consecutive men were tested for microorganisms. A polymicrobial flora was identified in the ulcers of 97 men. The microorganisms recovered from these ulcers included combinations of anaerobic and aerobic bacteria (including Mycoplasma), herpes simplex virus, yeasts, and filamentous fungi. Fifty-three study entrants had microorganisms, identified by culture or serologic tests, that were considered primary in ulcer pathogenesis. Herpes simplex virus was the most prevalent and Treponema pallidum was the next most prevalent pathogen identified. Of our patients, 5% had two recognized pathogens confirmed by laboratory tests, and only one of these was suspected at clinical examination. In addition, the study suggests that microorganisms other than Haemophilus ducreyi can produce ulcers with a morphology mimicking chancroid.
Collapse
|
37
|
|