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Kaisarly D, Meierhofer D, El Gezawi M, Rösch P, Kunzelmann KH. Effects of flowable liners on the shrinkage vectors of bulk-fill composites. Clin Oral Investig 2021; 25:4927-4940. [PMID: 33506426 PMCID: PMC8342399 DOI: 10.1007/s00784-021-03801-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Accepted: 01/19/2021] [Indexed: 01/08/2023]
Abstract
Objectives This investigation evaluated the effect of flowable liners beneath a composite restoration applied via different methods on the pattern of shrinkage vectors. Methods Forty molars were divided into five groups (n = 8), and cylindrical cavities were prepared and bonded with a self-etch adhesive (AdheSe). Tetric EvoCeram Bulk Fill (TBF) was used as the filling material in all cavities. The flowable liners Tetric EvoFlow Bulk Fill (TEF) and SDR were used to line the cavity floor. In gp1-TBF, the flowable composite was not used. TEF was applied in a thin layer in gp2-fl/TEF + TBF and gp3-fl/TEF + TBFincremental. Two flowable composites with a layer thickness of 2 mm were compared in gp4-fl/TEF + TBF and gp5-fl/SDR + TBF. TEF and SDR were mixed with radiolucent glass beads, while air bubbles inherently present in TBF served as markers. Each material application was scanned twice by micro-computed tomography before and after light curing. Scans were subjected to image segmentation for calculation of the shrinkage vectors. Results The absence of a flowable liner resulted in the greatest shrinkage vectors. A thin flowable liner (gp2-fl/TEF + TBFbulk) resulted in larger overall shrinkage vectors for the whole restoration than a thick flowable liner (gp4-fl/TEF + TBF). A thin flowable liner and incremental application (gp3-fl/TEF + TBFincremental) yielded the smallest shrinkage vectors. SDR yielded slightly smaller shrinkage vectors for the whole restoration than that observed in gp4-fl/TEF + TBF. Conclusions Thick flowable liner layers had a more pronounced stress-relieving effect than thin layers regardless of the flowable liner type. Clinical relevance It is recommended to apply a flowable liner (thin or thick) beneath bulk-fill composites, preferably incrementally.
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Affiliation(s)
- Dalia Kaisarly
- Department of Conservative Dentistry and Periodontology, University Hospital, Ludwig-Maximilians-University, Goethestrasse 70, 80336, Munich, Germany. .,Biomaterials Department, Faculty of Oral and Dental Medicine, Cairo University, Cairo, Egypt.
| | - D Meierhofer
- Department of Conservative Dentistry and Periodontology, University Hospital, Ludwig-Maximilians-University, Goethestrasse 70, 80336, Munich, Germany
| | - M El Gezawi
- Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - P Rösch
- University of Applied Sciences, Augsburg, Germany
| | - K H Kunzelmann
- Department of Conservative Dentistry and Periodontology, University Hospital, Ludwig-Maximilians-University, Goethestrasse 70, 80336, Munich, Germany
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Groh N, von Loetzen CS, Subbarayal B, Möbs C, Vogel L, Hoffmann A, Fötisch K, Koutsouridou A, Randow S, Völker E, Seutter von Loetzen A, Rösch P, Vieths S, Pfützner W, Bohle B, Schiller D. IgE and allergen-specific immunotherapy-induced IgG 4 recognize similar epitopes of Bet v 1, the major allergen of birch pollen. Clin Exp Allergy 2016; 47:693-703. [PMID: 27770477 DOI: 10.1111/cea.12835] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [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: 07/26/2016] [Revised: 09/14/2016] [Accepted: 09/26/2016] [Indexed: 12/20/2022]
Abstract
BACKGROUND Allergen-specific immunotherapy (AIT) with birch pollen generates Bet v 1-specific immunoglobulin (Ig)G4 which blocks IgE-mediated hypersensitivity mechanisms. Whether IgG4 specific for Bet v 1a competes with IgE for identical epitopes or whether novel epitope specificities of IgG4 antibodies are developed is under debate. OBJECTIVE We sought to analyze the epitope specificities of IgE and IgG4 antibodies from sera of patients who received AIT. METHODS 15 sera of patients (13/15 received AIT) with Bet v 1a-specific IgE and IgG4 were analyzed. The structural arrangements of recombinant (r)Bet v 1a and rBet v 1a_11x , modified in five potential epitopes, were analyzed by circular dichroism and nuclear magnetic resonance spectroscopy. IgE binding to Bet v 1 was assessed by ELISA and mediator release assays. Competitive binding of monoclonal antibodies specific for Bet v 1a and serum IgE/IgG4 to rBet v 1a and serum antibody binding to a non-allergenic Bet v 1-type model protein presenting an individual epitope for IgE was analyzed in ELISA and western blot. RESULTS rBet v 1a_11x had a Bet v 1a - similar secondary and tertiary structure. Monomeric dispersion of rBet v 1a_11x was concentration and buffer-dependent. Up to 1500-fold increase in the EC50 for IgE-mediated mediator release induced by rBet v 1a_11x was determined. The reduction of IgE and IgG4 binding to rBet v 1a_11x was comparable in 67% (10/15) of sera. Bet v 1a-specific monoclonal antibodies inhibited binding of serum IgE and IgG4 to 66.1% and 64.9%, respectively. Serum IgE and IgG4 bound specifically to an individual epitope presented by our model protein in 33% (5/15) of sera. CONCLUSION AND CLINICAL RELEVANCE Patients receiving AIT develop Bet v 1a-specific IgG4 which competes with IgE for partly identical or largely overlapping epitopes. The similarities of epitopes for IgE and IgG4 might stimulate the development of epitope-specific diagnostics and therapeutics.
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Affiliation(s)
- N Groh
- Division of Allergology, Paul-Ehrlich-Institut, Langen, Germany
| | - C S von Loetzen
- Department of Biopolymers, University of Bayreuth, Bayreuth, Germany
| | - B Subbarayal
- Department of Pathophysiology and Allergy Research and Christian Doppler Laboratory for Immunomodulation, Medical University of Vienna, Vienna, Austria
| | - C Möbs
- Department of Dermatology and Allergology, Philipps University Marburg, Marburg, Germany
| | - L Vogel
- Division of Allergology, Paul-Ehrlich-Institut, Langen, Germany
| | - A Hoffmann
- Division of Allergology, Paul-Ehrlich-Institut, Langen, Germany
| | - K Fötisch
- Division of Allergology, Paul-Ehrlich-Institut, Langen, Germany
| | - A Koutsouridou
- Division of Allergology, Paul-Ehrlich-Institut, Langen, Germany
| | - S Randow
- Division of Allergology, Paul-Ehrlich-Institut, Langen, Germany
| | - E Völker
- Division of Allergology, Paul-Ehrlich-Institut, Langen, Germany
| | | | - P Rösch
- Department of Biopolymers, University of Bayreuth, Bayreuth, Germany
| | - S Vieths
- Division of Allergology, Paul-Ehrlich-Institut, Langen, Germany
| | - W Pfützner
- Department of Dermatology and Allergology, Philipps University Marburg, Marburg, Germany
| | - B Bohle
- Department of Pathophysiology and Allergy Research and Christian Doppler Laboratory for Immunomodulation, Medical University of Vienna, Vienna, Austria
| | - D Schiller
- Division of Allergology, Paul-Ehrlich-Institut, Langen, Germany
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Husslik F, Nürnberg J, Seutter von Loetzen C, Mews T, Ballmer-Weber BK, Kleine-Tebbe J, Treudler R, Simon JC, Randow S, Völker E, Reuter A, Rösch P, Vieths S, Holzhauser T, Schiller D. The conformational IgE epitope profile of soya bean allergen Gly m 4. Clin Exp Allergy 2016; 46:1484-1497. [PMID: 27533495 DOI: 10.1111/cea.12796] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 07/06/2016] [Accepted: 07/11/2016] [Indexed: 11/30/2022]
Abstract
BACKGROUND Birch pollen-related soya allergy is mediated by Gly m 4. Conformational IgE epitopes of Gly m 4 are unknown. OBJECTIVE To identify the IgE epitope profile of Gly m 4 in subjects with birch pollen-related soya allergy utilizing an epitope library presented by Gly m 4-type model proteins. METHODS Sera from patients with (n = 26) and without (n = 19) allergy to soya as determined by oral provocation tests were studied. Specific IgE (Bet v 1/Gly m 4) was determined by ImmunoCAP. A library of 59 non-allergenic Gly m 4-type model proteins harbouring individual and multiple putative epitopes for IgE was tested in IgE binding assays. Primary, secondary and tertiary protein structures were assessed by mass spectrometry, circular dichroism and nuclear magnetic resonance spectroscopy. RESULTS All subjects were sensitized to Gly m 4 and Bet v 1. Allergen-specific serum IgE levels ranged from 0.94 to > 100 kUA /L. The avidities of serum IgE were 5.06 ng (allergic) and 1.8 ng (tolerant) as determined by EC50 for IgE binding to Gly m 4. 96% (46/48) of the protein variants bound IgE. Model proteins had Gly m 4-type conformation and individual IgE binding clustered in six major surface areas. Gly m 4-specific IgE binding could be inhibited to up to 80% by model proteins harbouring individual IgE binding sites in an epitope-wise equimolar fashion. Receiver operating curve analysis revealed an area under fitted curve of up to 0.88 for model proteins and 0.66 for Gly m 4. CONCLUSION AND CLINICAL RELEVANCE Serum levels and avidity of Gly m 4-specific IgE do not correlate with clinical reactivity to soya. Six IgE-binding areas, represented by 23 amino acids, account for more than 80% of total IgE binding capacity of Gly m 4. Model proteins may be used for epitope-resolved diagnosis to differentiate birch-soya allergy from clinical tolerance.
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Affiliation(s)
- F Husslik
- Division of Allergology, Paul-Ehrlich-Institut, Langen, Germany
| | - J Nürnberg
- Division of Allergology, Paul-Ehrlich-Institut, Langen, Germany
| | | | - T Mews
- Division of Allergology, Paul-Ehrlich-Institut, Langen, Germany
| | - B K Ballmer-Weber
- Centre for Dermatology and Allergology, Kantonsspital Luzern, Luzern, Switzerland.,Department of Dermatology, University Hospital Zurich, Zurich, Switzerland
| | | | - R Treudler
- Department of Dermatology, Venereology and Allergology, University of Leipzig, Leipzig, Germany
| | - J-C Simon
- Department of Dermatology, Venereology and Allergology, University of Leipzig, Leipzig, Germany
| | - S Randow
- Division of Allergology, Paul-Ehrlich-Institut, Langen, Germany
| | - E Völker
- Division of Allergology, Paul-Ehrlich-Institut, Langen, Germany
| | - A Reuter
- Division of Allergology, Paul-Ehrlich-Institut, Langen, Germany
| | - P Rösch
- Department of Biopolymers, University of Bayreuth, Bayreuth, Germany
| | - S Vieths
- Division of Allergology, Paul-Ehrlich-Institut, Langen, Germany
| | - T Holzhauser
- Division of Allergology, Paul-Ehrlich-Institut, Langen, Germany
| | - D Schiller
- Division of Allergology, Paul-Ehrlich-Institut, Langen, Germany.
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Pekar C, Berkner H, Vogel L, Gubesch M, Meisel L, Randow S, Ries L, Holzhauser T, Lidholm J, Vieths S, Rösch P, Hartl-Spiegelhauer O, Schiller D. Generation of a protein scaffold for the analysis of functional immunoglobulin epitopes of Bet v 1-like allergens. Clin Transl Allergy 2013. [PMCID: PMC3723550 DOI: 10.1186/2045-7022-3-s3-p102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- C Pekar
- Division of Allergology, Paul-Ehrlich-Institut, Langen, Germany
| | - H Berkner
- Thermo Fisher Scientific, Freiburg, Germany
| | - L Vogel
- Division of Allergology, Paul-Ehrlich-Institut, Langen, Germany
| | - M Gubesch
- Division of Allergology, Paul-Ehrlich-Institut, Langen, Germany
| | - L Meisel
- Division of Allergology, Paul-Ehrlich-Institut, Langen, Germany
| | - S Randow
- Division of Allergology, Paul-Ehrlich-Institut, Langen, Germany
| | - L Ries
- Division of Allergology, Paul-Ehrlich-Institut, Langen, Germany
| | - T Holzhauser
- Division of Allergology, Paul-Ehrlich-Institut, Langen, Germany
| | - J Lidholm
- Thermo Fisher Scientific, Uppsala, Sweden
| | - S Vieths
- Division of Allergology, Paul-Ehrlich-Institut, Langen, Germany
| | - P Rösch
- Department of Biopolymers, University of Bayreuth, Bayreuth, Germany
| | | | - D Schiller
- Division of Allergology, Paul-Ehrlich-Institut, Langen, Germany
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Schmitt M, Dietzek B, Neugebauer U, Krafft C, Rösch P, Popp J. Raman-Spektroskopie – der Weg zu einer labelfreien biomedizinischen Diagnostik. ACTA ACUST UNITED AC 2012. [DOI: 10.1055/s-0032-1325591] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- M. Schmitt
- Institut für Physikalische Chemie und Abbe Center of Photonics, Friedrich-Schiller-Universität Jena
| | - B. Dietzek
- Institut für Physikalische Chemie und Abbe Center of Photonics, Friedrich-Schiller-Universität Jena
| | | | - C. Krafft
- Institut für Photonische Technologien, Jena,
| | - P. Rösch
- Institut für Physikalische Chemie und Abbe Center of Photonics, Friedrich-Schiller-Universität Jena
| | - J. Popp
- Institut für Physikalische Chemie und Abbe Center of Photonics, Friedrich-Schiller-Universität Jena
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Stöckel S, Meisel S, Elschner M, Rösch P, Popp J. Identification of Bacillus anthracis via Raman Spectroscopy and Chemometric Approaches. Anal Chem 2012; 84:9873-80. [DOI: 10.1021/ac302250t] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- S. Stöckel
- Institute
of Physical Chemistry
and Abbe School of Photonics, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - S. Meisel
- Institute
of Physical Chemistry
and Abbe School of Photonics, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - M. Elschner
- Friedrich Loeffler Institut, Federal Research Institute for Animal Health, Institute
of Bacterial Infections and Zoonoses, Naumburger Straße 96a,
07743 Jena, Germany
| | - P. Rösch
- Institute
of Physical Chemistry
and Abbe School of Photonics, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - J. Popp
- Institute
of Physical Chemistry
and Abbe School of Photonics, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
- Institute of Photonic Technology, Albert-Einstein-Straße 9, 07745 Jena,
Germany
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7
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Neugebauer U, Große C, Bauer M, Kemper B, Barroso-Pena A, Bauwens A, Glueder M, Woerdemann M, Dewenter L, Denz C, Kloß S, Rösch P, Sabat A, Schütze K, Friedrich A, Bally GV, Popp J, Mellmann A. From Infection to Detection: Imaging S. aureus – host interactions. ACTA ACUST UNITED AC 2012. [DOI: 10.1515/bmt-2012-4284] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- U. Neugebauer
- Center for Sepsis Control and Care, University Hospital Jena, Germany
- Institute of Photonic Technology, Jena, Germany
| | - C. Große
- Center for Sepsis Control and Care, University Hospital Jena, Germany
- Institute of Photonic Technology, Jena, Germany
| | - M. Bauer
- Center for Sepsis Control and Care, University Hospital Jena, Germany
| | - B. Kemper
- Center for Biomedical Optics and Photonics, University of Münster, Münster, Germany
| | - A. Barroso-Pena
- Center for Biomedical Optics and Photonics, University of Münster, Münster, Germany
- Institute of Applied Physics, University of Münster, Münster, Germany
| | - A. Bauwens
- Institute for Hygiene, University of Münster, Münster, Germany
| | - M. Glueder
- Institute for Hygiene, University of Münster, Münster, Germany
| | - M. Woerdemann
- Institute of Applied Physics, University of Münster, Münster, Germany
| | - L. Dewenter
- Institute of Applied Physics, University of Münster, Münster, Germany
| | - C. Denz
- Institute of Applied Physics, University of Münster, Münster, Germany
| | - S. Kloß
- Institute of Physical Chemistry and Abbe School of Photonics, University Jena, Jena, Germany
| | - P. Rösch
- Institute of Physical Chemistry and Abbe School of Photonics, University Jena, Jena, Germany
| | - A. Sabat
- University Medical Centre Groningen, EurSafety Health-net, The Netherlands
| | | | - A. Friedrich
- University Medical Centre Groningen, EurSafety Health-net, The Netherlands
| | - G. von Bally
- Center for Biomedical Optics and Photonics, University of Münster, Münster, Germany
| | - J. Popp
- Institute of Photonic Technology, Jena, Germany
- Institute of Physical Chemistry and Abbe School of Photonics, University Jena, Jena, Germany
| | - A. Mellmann
- Institute for Hygiene, University of Münster, Münster, Germany
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Stöckel S, Meisel S, Elschner M, Rösch P, Popp J. Raman spectroscopic detection of anthrax endospores in powder samples. Angew Chem Int Ed Engl 2012; 51:5339-42. [PMID: 22505355 PMCID: PMC3470700 DOI: 10.1002/anie.201201266] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Indexed: 11/08/2022]
Affiliation(s)
- S Stöckel
- Institut für Physikalische Chemie, Friedrich-Schiller-Universität Jena, Jena, Germany
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9
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Stöckel S, Meisel S, Elschner M, Rösch P, Popp J. Raman-spektroskopische Detektion von Anthrax-Endosporen in Pulverproben. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201201266] [Citation(s) in RCA: 2] [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: 11/06/2022]
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Harz M, Rösch P, Popp J. Vibrational spectroscopy--a powerful tool for the rapid identification of microbial cells at the single-cell level. Cytometry A 2009; 75:104-13. [PMID: 19156822 DOI: 10.1002/cyto.a.20682] [Citation(s) in RCA: 161] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Rapid microbial detection and identification with a high grade of sensitivity and selectivity is a great and challenging issue in many fields, primarily in clinical diagnosis, pharmaceutical, or food processing technology. The tedious and time-consuming processes of current microbiological approaches call for faster ideally on-line identification techniques. The vibrational spectroscopic techniques IR absorption and Raman spectroscopy are noninvasive methods yielding molecular fingerprint information; thus, allowing for a fast and reliable analysis of complex biological systems such as bacterial or yeast cells. In this short review, we discuss recent vibrational spectroscopic advances in microbial identification of yeast and bacterial cells for bulk environment and single-cell analysis. IR absorption spectroscopy enables a bulk analysis whereas micro-Raman-spectroscopy with excitation in the near infrared or visible range has the potential for the analysis of single bacterial and yeast cells. The inherently weak Raman signal can be increased up to several orders of magnitude by applying Raman signal enhancement methods such as UV-resonance Raman spectroscopy with excitation in the deep UV region, surface enhanced Raman scattering, or tip-enhanced Raman scattering.
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Affiliation(s)
- M Harz
- Institute of Physical Chemistry, Friedrich-Schiller-Universität Jena, Helmholtzweg 4, Jena 07743, Germany
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11
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Lauber T, Tidten N, Matecko I, Zeeb M, Rösch P, Marx UC. Design and characterization of a soluble fragment of the extracellular ligand-binding domain of the peptide hormone receptor guanylyl cyclase-C. Protein Eng Des Sel 2008; 22:1-7. [PMID: 18987130 DOI: 10.1093/protein/gzn062] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The intestinal guanylyl cyclase-C (GC-C) was originally identified as an Escherichia coli heat-stable enterotoxin (STa) receptor. STa stimulates GC-C to much higher activity than the endogenous ligands guanylin and uroguanylin, causing severe diarrhea. To investigate the interactions of the endogenous and bacterial ligands with GC-C, we designed and characterized a soluble and properly folded fragment of the extracellular ligand-binding domain of GC-C. The membrane-bound guanylyl cyclases exhibit a single transmembrane spanning helix and a globularly folded extracellular ligand-binding domain that comprises about 410 of 1050 residues. Based on the crystal structure of the dimerized-binding domain of the guanylyl cyclase-coupled atrial natriuretic peptide receptor and a secondary structure-guided sequence alignment, we generated a model of the extracellular domain of GC-C comprised of two subdomains. Mapping of mutational and cross-link data onto this structural model restricts the ligand-binding region to the membrane proximal subdomain. We thus designed miniGC-C, a 197 amino acid fragment that mimics the ligand-binding membrane proximal subdomain. Cloning, expression and spectroscopic studies reveal miniGC-C to be a soluble and properly folded protein with a distinct secondary and tertiary structure. MiniGC-C binds STa with nanomolar affinity.
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Affiliation(s)
- T Lauber
- Lehrstuhl für Biopolymere and Forschungszentrum für Bio-Makromoleküle, Universität Bayreuth 95440, Bayreuth
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12
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Harz M, Krause M, Bartels T, Cramer K, Rösch P, Popp J. Minimal Invasive Gender Determination of Birds by Means of UV-Resonance Raman Spectroscopy. Anal Chem 2008; 80:1080-6. [DOI: 10.1021/ac702043q] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- M. Harz
- Institut für Physikalische Chemie, Friedrich-Schiller-Universität Jena, Helmholtzweg 4, 07743 Jena, Germany, Klinik für Vögel und Reptilien, Universität Leipzig, An den Tierkliniken 17, 04103 Leipzig, Germany, and Institut für Photonische Technologien, Albert-Einstein-Strasse 9, 07745 Jena, Germany
| | - M. Krause
- Institut für Physikalische Chemie, Friedrich-Schiller-Universität Jena, Helmholtzweg 4, 07743 Jena, Germany, Klinik für Vögel und Reptilien, Universität Leipzig, An den Tierkliniken 17, 04103 Leipzig, Germany, and Institut für Photonische Technologien, Albert-Einstein-Strasse 9, 07745 Jena, Germany
| | - T. Bartels
- Institut für Physikalische Chemie, Friedrich-Schiller-Universität Jena, Helmholtzweg 4, 07743 Jena, Germany, Klinik für Vögel und Reptilien, Universität Leipzig, An den Tierkliniken 17, 04103 Leipzig, Germany, and Institut für Photonische Technologien, Albert-Einstein-Strasse 9, 07745 Jena, Germany
| | - K. Cramer
- Institut für Physikalische Chemie, Friedrich-Schiller-Universität Jena, Helmholtzweg 4, 07743 Jena, Germany, Klinik für Vögel und Reptilien, Universität Leipzig, An den Tierkliniken 17, 04103 Leipzig, Germany, and Institut für Photonische Technologien, Albert-Einstein-Strasse 9, 07745 Jena, Germany
| | - P. Rösch
- Institut für Physikalische Chemie, Friedrich-Schiller-Universität Jena, Helmholtzweg 4, 07743 Jena, Germany, Klinik für Vögel und Reptilien, Universität Leipzig, An den Tierkliniken 17, 04103 Leipzig, Germany, and Institut für Photonische Technologien, Albert-Einstein-Strasse 9, 07745 Jena, Germany
| | - J. Popp
- Institut für Physikalische Chemie, Friedrich-Schiller-Universität Jena, Helmholtzweg 4, 07743 Jena, Germany, Klinik für Vögel und Reptilien, Universität Leipzig, An den Tierkliniken 17, 04103 Leipzig, Germany, and Institut für Photonische Technologien, Albert-Einstein-Strasse 9, 07745 Jena, Germany
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13
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Harz M, Claus RA, Bockmeyer CL, Baum M, Rösch P, Kentouche K, Deigner HP, Popp J. UV-resonance Raman spectroscopic study of human plasma of healthy donors and patients with thrombotic microangiopathy. Biopolymers 2006; 82:317-24. [PMID: 16506165 DOI: 10.1002/bip.20489] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [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: 11/11/2022]
Abstract
Various diseases shift the composition of human plasma; hence, the relative quantification of plasma constituents offers the opportunity to use the dynamic and complex composition of plasma to gain information on novel diagnostic and prognostic factors. Since plasma contains, besides water, mostly proteins, UV-resonance Raman spectroscopy (UVRR) seems to be a suitable method for investigating plasma. With this method the signals of aromatic amino acids and proteins are selectively enhanced. In this study an UV-resonance Raman approach was used for the investigation of human plasma of healthy volunteers and patients with thrombotic microangiopathy. For comparison, selected plasma components were analyzed for a more detailed characterization of cryoprecipitates from human plasma.
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Affiliation(s)
- M Harz
- Institute of Physical Chemistry, Friedrich-Schiller-University Jena, Helmholtzweg 4, D-07743 Jena, Germany
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14
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Gaus K, Rösch P, Petry R, Peschke KD, Ronneberger O, Burkhardt H, Baumann K, Popp J. Classification of lactic acid bacteria with UV-resonance Raman spectroscopy. Biopolymers 2006; 82:286-90. [PMID: 16421858 DOI: 10.1002/bip.20448] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.9] [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: 11/10/2022]
Abstract
UV-resonance Raman spectroscopy is applied as a method for the identification of lactic acid bacteria from yogurt. Eight different strains of bacteria from Lactobacillus acidophilus, L. delbrueckii ssp. bulgaricus, and Streptococcus thermophilus were investigated. At an excitation wavelength of 244 nm signals from nucleic acids and proteins are selectively enhanced. Classification was accomplished using different chemometric methods. In a first attempt, the unsupervised methods hierarchical cluster analysis and principal component analysis were applied to investigate natural grouping in the data. In a second step the spectra were analyzed using several supervised methods: K-nearest neighbor classifier, nearest mean classifier, linear discriminant analysis, and support vector machines.
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Affiliation(s)
- K Gaus
- Institut für Physikalische Chemie, Friedrich-Schiller-Universität Jena, Helmholtzweg 4, 07743 Jena, Germany
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15
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Abstract
For a fast identification of eukaryotic cells such as yeast species without a cultivation step it should be possible to perform the investigation on only one single cell. Since yeasts as eukaryotes are heterogeneous and their Raman spectra are therefore dependent on the measuring position, one Raman spectra is not representative of the whole cell. In this contribution we demonstrate the application of average Raman spectra of a line scan over single yeast cells. These average spectra are used for classification with the help of a support vector machine.
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Affiliation(s)
- P Rösch
- Institut für Physikalische Chemie, Friedrich-Schiller-Universität Jena, Helmholtzweg 4, 07743 Jena, Germany
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16
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Strehle MA, Rösch P, Baranska M, Schulz H, Popp J. On the way to a quality control of the essential oil of fennel by means of Raman spectroscopy. Biopolymers 2005; 77:44-52. [PMID: 15578676 DOI: 10.1002/bip.20178] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [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: 11/06/2022]
Abstract
Essential oils are one of the most valuable natural products. The price of special essential oils that can be purchased on the market strongly depends on the quality of the product. The quality, which depends on the quantitative and qualitative variation of different monoterpenes, varies with respect of the origin and the harvesting period. This contribution reports on a Raman spectroscopic study on the essential oil occurring in fennel. Cross-sections of fennel seed were investigated by use of Raman spectroscopy and Raman mapping to localize the essential oil and to analyze its chemical composition directly in the plant. Furthermore the practicability of a home-built mobile transportable Raman spectrometer to perform on-site measurements was successfully tested.
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Affiliation(s)
- M A Strehle
- Institut für Physikalische Chemie, Friedrich-Schiller-Universität Jena, Helmholtzweg 4, D-07743 Jena, Germany
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17
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Harz M, Rösch P, Peschke KD, Ronneberger O, Burkhardt H, Popp J. Micro-Raman spectroscopic identification of bacterial cells of the genus Staphylococcus and dependence on their cultivation conditions. Analyst 2005; 130:1543-50. [PMID: 16222378 DOI: 10.1039/b507715j] [Citation(s) in RCA: 130] [Impact Index Per Article: 6.8] [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: 11/21/2022]
Abstract
Microbial contamination is not only a medical problem, but also plays a large role in pharmaceutical clean room production and food processing technology. Therefore many techniques were developed to achieve differentiation and identification of microorganisms. Among these methods vibrational spectroscopic techniques (IR, Raman and SERS) are useful tools because of their rapidity and sensitivity. Recently we have shown that micro-Raman spectroscopy in combination with a support vector machine is an extremely capable approach for a fast and reliable, non-destructive online identification of single bacteria belonging to different genera. In order to simulate different environmental conditions we analyzed in this contribution different Staphylococcus strains with varying cultivation conditions in order to evaluate our method with a reliable dataset. First, micro-Raman spectra of the bulk material and single bacterial cells that were grown under the same conditions were recorded and used separately for a distinct chemotaxonomic classification of the strains. Furthermore Raman spectra were recorded from single bacterial cells that were cultured under various conditions to study the influence of cultivation on the discrimination ability. This dataset was analyzed both with a hierarchical cluster analysis (HCA) and a support vector machine (SVM).
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Affiliation(s)
- M Harz
- Institut für Physikalische Chemie, Friedrich-Schiller-Universität Jena, Helmholtzweg 4, 07743 Jena, Germany
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18
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Baranska M, Schulz H, Siuda R, Strehle MA, Rösch P, Popp J, Joubert E, Manley M. Quality control ofHarpagophytum procumbensand its related phytopharmaceutical products by means of NIR-FT-Raman spectroscopy. Biopolymers 2004; 77:1-8. [PMID: 15558669 DOI: 10.1002/bip.20158] [Citation(s) in RCA: 30] [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: 11/07/2022]
Abstract
NIR-FT-Raman spectroscopy was used for identification and quantification of harpagoside in secondary roots of Harpagophytum procumbens as well as in related phytopharmaceutical products, e.g., ethanolic extracts and tablets. Applied Raman mappings reveal the spatial distribution of this valuable iridoid glycoside within the different samples. The same technique can be used for quality control purposes beginning from the plant to its final products. Based on the obtained spectral data and reference HPLC values of harpagoside, a reliable multivariate calibration model was developed.
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Affiliation(s)
- M Baranska
- Federal Centre for Breeding Research on Cultivated Plants (BAZ), Institute for Plant Analysis, Neuer Weg 22-23, 06484 Quedlinburg, Germany
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19
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Gessner R, Winter C, Rösch P, Schmitt M, Petry R, Kiefer W, Lankers M, Popp J. Identification of Biotic and Abiotic Particles by Using a Combination of Optical Tweezers and In Situ Raman Spectroscopy. Chemphyschem 2004; 5:1159-70. [PMID: 15446738 DOI: 10.1002/cphc.200400026] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [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: 11/07/2022]
Abstract
A highly versatile setup, which introduces an optical gradient trap into a Raman spectrometer, is presented. The particular configuration, which consists of two lasers, makes trapping independent from the Raman excitation laser and allows a separate adjustment of the trapping and excitation wavelengths. Thus, the excitation wavelength can be chosen according to the needs of the application. We describe the successful application of an optical gradient trap on transparent as well as on reflective, metal-coated microparticles. Raman spectra were recorded from optically trapped polystyrene beads and from single biological cells (e.g., erythrocytes, yeast cells). Also, metal-coated microparticles were trapped and used as surface enhanced Raman spectroscopy (SERS) substrates for tests on yeast cells. Furthermore, the optical gradient trap was combined with a SERS fiber probe. Raman spectra were recorded from trapped red blood cells using the SERS fiber probe for excitation.
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Affiliation(s)
- R Gessner
- Institut für Physikalische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
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20
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Rösch P, Schneider H, Zimmermann U, Kiefer W, Popp J. In situ Raman investigation of single lipid droplets in the water-conducting xylem of four woody plant species. Biopolymers 2004; 74:151-6. [PMID: 15137114 DOI: 10.1002/bip.20062] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [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: 11/08/2022]
Abstract
A micro-Raman spectroscopy approach was used for the direct in situ characterization of lipid bodies in the water-conducting branch xylem of an African resurrection plant and three deciduous European tree species. Because of average diameters of at least 1 microm, the lipid bodies of all investigated species proved to be easily accessible by this technique. All vesicle-forming xylem lipids were identified as fatty acid esters, which may correspond to phospholipids. Whereas in the resurrection plant saturated lipids were dominant, the lipid bodies of the European trees consisted of highly unsaturated fatty acids. A comparison of the spectra of lipid droplets of lime obtained in situ and from isolated xylem sap revealed slightly different signatures. This finding suggests that micro-Raman spectroscopy may be used to detect modifications of the chemical composition of biological substances as a result of the extraction mode.
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Affiliation(s)
- P Rösch
- Institut für Physikalische Chemie, Friedrich-Schiller-Universität Jena, Helmholtzweg 4, 07743 Jena, Germany
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21
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Strehle MA, Rösch P, Petry R, Hauck A, Thull R, Kiefer W, Popp J. A Raman spectroscopic study of the adsorption of fibronectin and fibrinogen on titanium dioxide nanoparticles. Phys Chem Chem Phys 2004. [DOI: 10.1039/b406524g] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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22
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Gessner R, Rösch P, Petry R, Schmitt M, Strehle MA, Kiefer W, Popp J. The application of a SERS fiber probe for the investigation of sensitive biological samples. Analyst 2004; 129:1193-9. [PMID: 15565217 DOI: 10.1039/b411690a] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.5] [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: 11/21/2022]
Abstract
The applicability of an etched and silver or gold coated SERS fiber probe in combination with a commercially available laboratory micro-Raman setup or a home built mobile micro-Raman setup to perform on-site field measurements was evaluated and successfully tested on different biological samples. The SERS fiber probe allows one to perform measurements with high spatial resolution. Simultaneously, the laser power used for Raman spectroscopy on biological samples as compared with conventional Raman experiments can be reduced by more than two orders of magnitude. This experimental arrangement was tested to investigate sensitive biological samples like mint plants (Bergamot mint, spear mint) and citrus fruits (kumquat). Furthermore, traces of fungicides on wine leaves were detected by means of such a SERS fiber probe setup.
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Affiliation(s)
- R Gessner
- Institut für Physikalische Chemie, Universität Jena, Helmholtzweg 4, D-07743 Jena, Germany
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23
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24
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Abstract
The characterization of mints is often problematic because Mentha is a taxonomically complex genus. In order to provide a fast and easy characterization method, we use a combination of micro-Raman spectroscopy and hierarchical cluster analysis. A classification trial of different mint taxa is possible for one collection time. For spectra measured at different points during the growing season, a more sophisticated pretreatment of the data is necessary to receive good discrimination between the species, as well as between the subspecies and varieties of the mints.
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Affiliation(s)
- P Rösch
- Institut für Physikalische Chemie, Universität Würzburg, Am Hubland, Germany
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25
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Gessner R, Rösch P, Kiefer W, Popp J. Raman spectroscopy investigation of biological materials by use of etched and silver coated glass fiber tips. Biopolymers 2002; 67:327-30. [PMID: 12012459 DOI: 10.1002/bip.10090] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [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: 11/06/2022]
Abstract
The results for surface enhanced Raman scattering (SERS) studies on biological samples are reported. Etched and silver coated glass fiber tips were used as a SERS substrate. This method enabled the recording of spectra of biological samples, such as plant tissue or microbiological cells, with a high spatial resolution. Because of the low laser power used with the fiber tips, it was even possible to investigate tissues that are very sensitive toward laser power as it is used in a common micro-Raman setup.
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Affiliation(s)
- R Gessner
- Institute for Physical Chemistry, Am Hubland, Würzburg D-97074, Germany
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26
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Bauer F, Schweimer K, Klüver E, Conejo-Garcia JR, Forssmann WG, Rösch P, Adermann K, Sticht H. Structure determination of human and murine beta-defensins reveals structural conservation in the absence of significant sequence similarity. Protein Sci 2001; 10:2470-9. [PMID: 11714914 PMCID: PMC2374044 DOI: 10.1110/ps.24401] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Defensins are cationic and cysteine-rich peptides that play a crucial role in the host defense against microorganisms of many organisms by their capability to permeabilize bacterial membranes. The low sequence similarity among the members of the large mammalian beta-defensin family suggests that their antimicrobial activity is largely independent of their primary structure. To investigate to what extent these defensins share a similar fold, the structures of the two human beta-defensins, hBD-1 and hBD-2, as well as those of two novel murine defensins, termed mBD-7 and mBD-8, were determined by nuclear magnetic resonance spectroscopy. All four defensins investigated share a striking similarity on the level of secondary and tertiary structure including the lack of a distinct hydrophobic core, suggesting that the fold is mainly stabilized by the presence of three disulfide bonds. In addition to the overall shape of the molecules, the ratio of solvent-exposed polar and hydrophobic side chains is also very similar among the four defensins investigated. It is significant that beta-defensins do not exhibit a common pattern of charged and hydrophobic residues on the protein surface and that the beta-defensin-specific fold appears to accommodate a wide range of different amino acids at most sequence positions. In addition to the implications for the mode of biological defensin actions, these findings are of particular interest because beta-defensins have been suggested as lead compounds for the development of novel peptide antibiotics for the therapy of infectious diseases.
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Affiliation(s)
- F Bauer
- Lehrstuhl für Biopolymere, Universität Bayreuth, D-95440 Bayreuth, Germany
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27
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Neudecker P, Sticht H, Rösch P. Improving the efficiency of the Gaussian conformational database potential for the refinement of protein and nucleic acid structures. J Biomol NMR 2001; 21:373-375. [PMID: 11824757 DOI: 10.1023/a:1013369107271] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Affiliation(s)
- P Neudecker
- Lehrstuhl für Biopolymere, Universität Bayreuth, Germany.
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28
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Neudecker P, Schweimer K, Nerkamp J, Scheurer S, Vieths S, Sticht H, Rösch P. Allergic cross-reactivity made visible: solution structure of the major cherry allergen Pru av 1. J Biol Chem 2001; 276:22756-63. [PMID: 11287426 DOI: 10.1074/jbc.m101657200] [Citation(s) in RCA: 133] [Impact Index Per Article: 5.8] [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: 11/06/2022] Open
Abstract
Birch pollinosis is often accompanied by hypersensitivity to fruit as a consequence of the cross-reaction of pollen allergen-specific IgE antibodies with homologous food proteins. To provide a basis for examining the cross-reactivity on a structural level, we used heteronuclear multidimensional NMR spectroscopy to determine the high-resolution three-dimensional structure of the major cherry allergen, Pru av 1, in solution. Based on a detailed comparison of the virtually identical structures of Pru av 1 and Bet v 1, the major birch pollen allergen, we propose an explanation for a significant aspect of the observed cross-reactivity pattern among the family of allergens under consideration. The large hydrophobic cavity expected to be important for the still unknown physiological function of Bet v 1 is conserved in Pru av 1. Structural homology to a domain of human MLN64 associated with cholesterol transport suggests phytosteroids as putative ligands for Pru av 1. NMR spectroscopy provides experimental evidence that Pru av 1 interacts with phytosteroids, and molecular modeling shows that the hydrophobic cavity is large enough to accommodate two such molecules.
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Affiliation(s)
- P Neudecker
- Lehrstuhl für Biopolymere, Universität Bayreuth, D-95440 Bayreuth, Germany
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29
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Lauber T, Marx UC, Schulz A, Kreutzmann P, Rösch P, Hoffmann S. Accurate disulfide formation in Escherichia coli: overexpression and characterization of the first domain (HF6478) of the multiple Kazal-type inhibitor LEKTI. Protein Expr Purif 2001; 22:108-12. [PMID: 11388807 DOI: 10.1006/prep.2001.1415] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [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: 11/22/2022]
Abstract
The human hemofiltrate peptide HF6478, a putative serine proteinase inhibitor, which is part of the precursor protein LEKTI, was cloned, overexpressed, and purified. HF6478 contains two disulfide bridges with 1-4, 2-3 connectivity, sharing partial homology to Kazal-type domains and other serine proteinase inhibitors. It was expressed as thioredoxin (Trx) fusion protein, and disulfide formation occurred in the oxidative cytoplasm of Escherichia coli Origami (DE3) strain which carries a trxB(-)/gor522(-) double mutation. The soluble fusion protein was purified using metal-chelating affinity chromatography. Cleavage of the Trx fusion protein with factor Xa and subsequent purification yielded the final product in amounts sufficient for structural studies. Characterization of recombinant HF6478 was done by amino acid sequencing, mass spectrometry, capillary zone electrophoresis, and CD spectroscopy. Taking the blood filtrate peptide HF6478 as example, we present a strategy which should facilitate the expression of different extracellular proteins in the E. coli cytoplasm.
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Affiliation(s)
- T Lauber
- Lehrstuhl für Biopolymere, Universität Bayreuth, Universitätstrasse 30, 95447 Bayreuth, Germany
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30
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Affiliation(s)
- P Rösch
- Department of Biopolymers, University of Bayreuth, Germany.
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31
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Faber C, Schärpf M, Becker T, Sticht H, Rösch P. The structure of the coliphage HK022 Nun protein-lambda-phage boxB RNA complex. Implications for the mechanism of transcription termination. J Biol Chem 2001; 276:32064-70. [PMID: 11356847 DOI: 10.1074/jbc.m102975200] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Nun protein from coliphage HK022 binds to phage boxB RNA and functions, in contrast to phage lambda N protein, as a transcriptional terminator. The basic Nun-(10-44) peptide contains the boxB RNA binding arginine rich motif, ARM. The peptide binds boxB RNA and competes with the phage lambda ARM peptide N-(1-36) as indicated by nuclear magnetic resonance (NMR) spectroscopy titrations. In two-dimensional nuclear Overhauser enhancement spectroscopy experiments boxB RNA in complex with Nun-(20-44) exhibits the same pattern of resonances as it does in complex with N peptides containing the ARM, and we could show that Nun-(20-44) forms a bent alpha-helix upon binding to the boxB RNA. The structure of the boxB RNA-bound Nun-(20-44) was determined on the basis of 191 intra- and 30 intermolecular distance restraints. Ser-24 is anchored to the lower RNA stem, and stacking of Tyr-39 and A7 is clearly experimentally indicated. Arg-28 shows numerous contacts to the RNA stem. Leu-22, Ile-30, Trp-33, Ile-37, and Leu-41 form a hydrophobic surface, which could be a recognition site for additional host factors such as NusG. Such a hydrophobic surface area is not present in N-(1-36) bound to boxB RNA.
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Affiliation(s)
- C Faber
- Lehrstuhl für Biopolymere, Universität Bayreuth, Universitätsstr. 30, 95440 Bayreuth, Germany
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32
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Neudecker P, Schweimer K, Nerkamp J, Boehm M, Scheurer S, Vieths S, Sticht H, Rösch P. Sequence-specific 1H, 13C and 15N resonance assignments of the major cherry allergen Pru a 1. J Biomol NMR 2000; 18:71-72. [PMID: 11061231 DOI: 10.1023/a:1008357100592] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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33
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Schweimer K, Hoffmann S, Wastl J, Maier UG, Rösch P, Sticht H. Solution structure of a zinc substituted eukaryotic rubredoxin from the cryptomonad alga Guillardia theta. Protein Sci 2000; 9:1474-86. [PMID: 10975569 PMCID: PMC2144721 DOI: 10.1110/ps.9.8.1474] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [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: 10/21/2022]
Abstract
The rubredoxin from the cryptomonad Guillardia theta is one of the first examples of a rubredoxin encoded in a eukaryotic organism. The structure of a soluble zinc-substituted 70-residue G. theta rubredoxin lacking the membrane anchor and the thylakoid targeting sequence was determined by multidimensional heteronuclear NMR, representing the first three-dimensional (3D) structure of a eukaryotic rubredoxin. For the structure calculation a strategy was applied in which information about hydrogen bonds was directly inferred from a long-range HNCO experiment, and the dynamics of the protein was deduced from heteronuclear nuclear Overhauser effect data and exchange rates of the amide protons. The structure is well defined, exhibiting average root-mean-square deviations of 0.21 A for the backbone heavy atoms and 0.67 A for all heavy atoms of residues 7-56, and an increased flexibility toward the termini. The structure of this core fold is almost identical to that of prokaryotic rubredoxins. There are, however, significant differences with respect to the charge distribution at the protein surface, suggesting that G. theta rubredoxin exerts a different physiological function compared to the structurally characterized prokaryotic rubredoxins. The amino-terminal residues containing the putative signal peptidase recognition/cleavage site show an increased flexibility compared to the core fold, but still adopt a defined 3D orientation, which is mainly stabilized by nonlocal interactions to residues of the carboxy-terminal region. This orientation might reflect the structural elements and charge pattern necessary for correct signal peptidase recognition of the G. theta rubredoxin precursor.
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Affiliation(s)
- K Schweimer
- Lehrstuhl für Biopolymere, Universität Bayreuth, Germany
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34
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Abstract
Binding of human immunodeficiency virus type 1 (HIV-1) transactivator (Tat) protein to Tat-responsive RNA (TAR) is essential for viral replication and is considered a promising starting point for the design of anti-HIV drugs. NMR spectroscopy indicated that the aminoglycosides neomycin B and ribostamycin bind to TAR and that neomycin is able to inhibit Tat binding to TAR. The solution structure of the neomycin-bound TAR has been determined by NMR spectroscopy. Chemical shift mapping and intermolecular nuclear Overhauser effects define the binding region of the aminoglycosides on TAR and give strong evidence for minor groove binding. Based on 15 nuclear Overhauser effect-derived intermolecular distance restraints, a model structure of the TAR-neomycin complex was calculated. Neomycin is bound in a binding pocket formed by the minor groove of the lower stem and the uridine-rich bulge of TAR, which adopts a conformation different from those known. The neamine core of the aminoglycoside (rings I and II) is covered with the bulge, explaining the inhibition of Tat by an allosteric mechanism. Neomycin reduces the volume of the major groove in which Tat is bound and thus impedes essential protein-RNA contacts.
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Affiliation(s)
- C Faber
- Lehrstuhl für Biopolymere, Universität Bayreuth, D-95447 Bayreuth, Germany
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35
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Weidler M, Reinhard C, Friedrich G, Wieland FT, Rösch P. Structure of the cytoplasmic domain of p23 in solution: implications for the formation of COPI vesicles. Biochem Biophys Res Commun 2000; 271:401-8. [PMID: 10799309 DOI: 10.1006/bbrc.2000.2511] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [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: 11/22/2022]
Abstract
Coatomer, the coat protein complex of coat protein (COPI) vesicles, is involved in the budding of these vesicles. Its interaction with the cytoplasmic domains of some p24-family members, type I transmembrane proteins of the Golgi, has been shown to induce a conformational change of coatomer that initiates polymerization of the complex. From stoichiometrical data it is likely that interaction of coatomer with the small tail domains involves an oligomeric form of the p24 proteins. Here we present the structure of peptide analogs of the cytoplasmic domain of p23, a member of the p24 family, as determined by two-dimensional nuclear magnetic resonance spectroscopy in the presence of 2,2,2-trifluoroethanol. An improved strategy for structure calculation revealed that the tail domain peptides form alpha-helices and adopt a tetrameric state. Based on these results we propose an initial model for the binding of coatomer by p23 and the induced conformational change of coatomer that results in its polymerization, curvature of the Golgi membrane to form a bud, and finally a COPI-coated vesicle.
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Affiliation(s)
- M Weidler
- Lehrstuhl für Biopolymere, Universität Bayreuth, Germany.
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36
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Abstract
We have identified an open reading frame with homology to prokaryotic rubredoxins (rds) on a nucleomorph chromosome of the cryptomonad alga Guillardia theta. cDNA analysis let us propose that the rd preprotein has an NH(2)-terminal extension that functions as a transit peptide for import into the plastid. Compared to rds found in non-photosynthetic prokaryotes or found in bacteria that exhibit an anoxigenic photosynthesis apparatus, nucleomorph rd has a COOH-terminal extension, which shows high homology exclusively to the COOH-termini of cyanobacterial rds as well as to a hypothetical rd in the Arabidopsis genome. This extension can be divided into a putative membrane anchor and a stretch of about 20 amino acids with unknown function linking the common rd fold to this anchor. Overexpression of nucleomorph rd in Escherichia coli using a T7 RNA polymerase/promotor system resulted in a mixture of iron-containing holorubredoxin and zinc-substituted protein. Preliminary spectroscopic studies of the iron form of nucleomorph rd suggest the existence of a native rd-type iron site. One-dimensional nuclear magnetic resonance spectroscopy of recombinant Zn-rd suggests the presence of a stable tertiary fold similar to that of other rd structures determined previously.
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Affiliation(s)
- J Wastl
- Cell Biology and Applied Botany, Philipps-University Marburg, Karl-von-Frisch-Strasse, D-35032, Marburg, Germany
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37
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Schärpf M, Sticht H, Schweimer K, Boehm M, Hoffmann S, Rösch P. Antitermination in bacteriophage lambda. The structure of the N36 peptide-boxB RNA complex. Eur J Biochem 2000; 267:2397-408. [PMID: 10759866 DOI: 10.1046/j.1432-1327.2000.01251.x] [Citation(s) in RCA: 67] [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: 11/20/2022]
Abstract
The solution structure of a 15-mer nutRboxB RNA hairpin complexed with the 36-mer N-terminal peptide of the N protein (N36) from bacteriophage lambda was determined by 2D and 3D homonuclear and heteronuclear magnetic resonance spectroscopy. These 36 amino acids include the arginine-rich motif of the N protein involved in transcriptional antitermination of phage lambda. Upon complex formation with boxB RNA, the synthetic N36 peptide binds tightly to the major groove of the boxB hairpin through hydrophobic and electrostatic interactions forming a bent alpha helix. Four nucleotides of the GAAAA pentaloop of the boxB RNA adopt a GNRA-like tetraloop fold in the complex. The formation of a GAAA tetraloop involves a loop-closing sheared base pair (G6-A10), base stacking of three adenines (A7, A8, and A10), and extrusion of one nucleotide (A9) from the loop, as observed previously for the complex of N(1-22) peptide and the nutLboxB RNA [Legault, P., Li, J., Mogridge, J., Kay, L.E. & Greenblatt, J. (1998) Cell 93, 289-299]. Stacking of the bases is extended by the indole-ring of Trp18 which also forms hydrophobic contacts to the side-chains of Leu24, Leu25, and Val26. Based on the structure of the complex, three mutant peptides were synthesized and investigated by CD and NMR spectroscopy in order to determine the role of particular residues for complex formation. These studies revealed very distinct amino-acid requirements at positions 3, 4, and 8, while replacement of Trp18 with tyrosine did not result in any gross structural changes.
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Affiliation(s)
- M Schärpf
- Lehrstuhl für Biopolymere der Universität Bayreuth, Germany
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38
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Schweimer K, Marg BL, Oesterhelt D, Rösch P, Sticht H. Sequence-specific 1H, 13C and 15N resonance assignments and secondary structure of [2Fe-2S] ferredoxin from Halobacterium salinarum. J Biomol NMR 2000; 16:347-348. [PMID: 10826887 DOI: 10.1023/a:1008381016258] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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39
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Marx UC, Adermann K, Bayer P, Forssmann WG, Rösch P. Solution structures of human parathyroid hormone fragments hPTH(1-34) and hPTH(1-39) and bovine parathyroid hormone fragment bPTH(1-37). Biochem Biophys Res Commun 2000; 267:213-20. [PMID: 10623601 DOI: 10.1006/bbrc.1999.1958] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.3] [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: 11/22/2022]
Abstract
Parathyroid hormone (PTH) is involved in regulation of the calcium level in blood and has an influence on bone metabolism, thus playing a role in osteoporosis therapy. In this study, the structures of the human PTH fragments (1-34) and (1-39) as well as bovine PTH(1-37) in aqueous buffer solution under near physiological conditions were determined using two-dimensional nuclear magnetic resonance spectroscopy. The overall structure of the first 34 amino acids of these three peptides is virtually identical, exhibiting a short NH(2)-terminal and a longer COOH-terminal helix as well as a defined loop region from His14 to Ser17, stabilized by hydrophobic interactions. bPTH(1-37), which has a higher biological activity, shows a better-defined NH(2)-terminal part. In contrast to NH(2)-terminal truncations, which cause destabilization of helical structure, neither COOH-terminal truncation nor elongation significantly influences the secondary structure. Furthermore, we investigated the structure of hPTH(1-34) in 20% trifluoroethanol solution. In addition to its helix-stabilizing effect, trifluorethanol causes the loss of tertiary hydrophobic interactions.
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Affiliation(s)
- U C Marx
- Lehrstuhl für Biopolymere, Universität Bayreuth, Bayreuth, D-95440, Germany.
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40
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Abstract
Human CC chemokine 2 (HCC-2) is a novel member of the chemokine peptide family that induces chemotaxis of monocytes, T lymphocytes and eosinophils via activation of the CCR-1 and CCR-3 receptors. Fmoc chemistry was optimized and used to synthesize the biologically active 66-residue peptide HCC-2-(48-113). Introduction of the three disulfide bonds was achieved by oxidative folding in the presence of the redox system cysteine/cystine. Alternatively, a semiselective approach utilizing a mixed Acm/Trt protection scheme for disulfide formation was applied. It was found that, without participation of the two HCC-2-specific cysteine residues in positions 64 and 104, the two typical chemokine disulfides are formed predominantly during oxidative folding. In addition, the mutant [Ala64,104]HCC-2-(48-113) lacking the third disulfide bond that discriminates HCC-2 from most other chemokines was synthesized. For disulfide bond formation, oxidative folding was compared with the use of Acm/Trt protection. HCC-2-(48-113) and the mutant [Ala64,104]HCC-2-(48-113) were further analyzed by CD and one-dimensional 1H NMR-spectroscopy. Both peptides adopt a similar stable secondary and tertiary structure in solution.
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Affiliation(s)
- S E Escher
- Niedersächsisches Institut für Peptid-Forschung, Hannover, Germany
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41
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Abstract
Guanylin is a guanylyl cyclase (GC)-activating peptide that is mainly secreted as the corresponding prohormone of 94 amino acid residues. In this study, we show that the originally isolated 15-residue guanylin, representing the COOH-terminal part of the prohormone, is released from the prohormone by cleavage of an Asp-Pro amide bond under conditions applied during the isolation procedures. Thus, the 15-residue guanylin is probably a non-native, chemically induced GC-activating peptide. This guanylin molecule contains two disulfide bonds that are absolutely necessary for receptor activation. We demonstrate that the folding of the reduced 15-residue guanylin results almost completely in the formation of the two inactive disulfide isomers. In contrast, the reduced form of proguanylin containing the entire prosequence folds to a product with the native cysteine connectivity. Because proguanylin lacking the 31 NH2-terminal residues of the prosequence folds only to a minor extent to guanylin with the native disulfide bonds, it is evident that this NH2-terminal region contributes significantly to the correct disulfide-coupled folding. Structural studies using CD and NMR spectroscopy show that native proguanylin contains a considerable amount of alpha-helical and, to a lesser extent, beta-sheet structural elements. In addition, a close proximity of the NH2- and the COOH-terminal regions was found by NOESY. It appears that this interaction is important for the constitution of the correct conformation and provides an explanation of the minor guanylyl cyclase activity of proguanylin by shielding the bioactive COOH-terminal domain from the receptor.
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Affiliation(s)
- A Schulz
- Niedersächsisches Institut für Peptid-Forschung, Hannover, Germany
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42
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Sticht H, Escher SE, Schweimer K, Forssmann WG, Rösch P, Adermann K. Solution structure of the human CC chemokine 2: A monomeric representative of the CC chemokine subtype. Biochemistry 1999; 38:5995-6002. [PMID: 10320325 DOI: 10.1021/bi990065i] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
HCC-2, a 66-amino acid residue human CC chemokine, was reported to induce chemotaxis on monocytes, T-lymphocytes, and eosinophils. The three-dimensional structure of HCC-2 has been determined by 1H nuclear magnetic resonance (NMR) spectroscopy and restrained molecular dynamics calculations on the basis of 871 experimental restraints. The structure is well-defined, exhibiting average root-mean-square deviations of 0.58 and 0.96 A for the backbone heavy atoms and all heavy atoms of residues 5-63, respectively. In contrast to most other chemokines, subtle structural differences impede dimer formation of HCC-2 in a concentration range of 0.1 microM to 2 mM. HCC-2, however, exhibits the same structural elements as the other chemokines, i.e., a triple-stranded antiparallel beta-sheet covered by an alpha-helix, showing that the chemokine fold is not influenced by quaternary interactions. Structural investigations with a HCC-2 mutant prove that a third additional disulfide bond present in wild-type HCC-2 is not necessary for maintaining the relative orientation of the helix and the beta-sheet.
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Affiliation(s)
- H Sticht
- Lehrstuhl für Biopolymere, Universität Bayreuth, D-95440 Bayreuth, Germany.
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43
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Weidler M, Marx UC, Seidel G, Schäfer W, Hoffmann E, Esswein A, Rösch P. The structure of human parathyroid hormone-related protein(1-34) in near-physiological solution. FEBS Lett 1999; 444:239-44. [PMID: 10050767 DOI: 10.1016/s0014-5793(98)01658-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [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: 10/18/2022]
Abstract
Parathyroid hormone-related protein plays a major role in the pathogenesis of humoral hypercalcemia of malignancy. Under normal physiological conditions, parathyroid hormone-related protein is produced in a wide variety of tissues and acts in an autocrine or paracrine fashion. Parathyroid hormone-related protein and parathyroid hormone bind to and activate the same G-protein-coupled receptor. Here we present the structure of the biologically active NH2-terminal domain of human parathyroid hormone-related protein(1-34) in near-physiological solution in the absence of crowding reagents as determined by two-dimensional proton magnetic resonance spectroscopy. An improved strategy for structure calculation revealed the presence of two helices, His-5-Leu-8 and Gln-16-Leu-27, connected by a flexible linker. The parathyroid hormone-related protein(1-34) structure and the structure of human parathyroid hormone(1-37) as well as human parathyroid hormone(1-34) are highly similar, except for the well defined turn, His-14-Ser-17, present in parathyroid hormone. Thus, the similarity of the binding affinities of parathyroid hormone and parathyroid hormone-related protein to their common receptor may be based on their structural similarity.
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Affiliation(s)
- M Weidler
- Lehrstuhl für Biopolymere, Universität Bayreuth, Germany
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45
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Abstract
The trans-activator protein (Tat) of human immunodeficiency virus type 1 (HIV-1) binds to an uridine-rich bulge of an RNA target (TAR; trans-activation responsive element) predominantly via its basic sequence domain. The structure of the Tat(46-58)-TAR complex has been determined by a novel modeling approach relying on structural information about one crucial arginine residue and crosslink data. The strategy described here solely uses this experimental data without additional "modeling" assumptions about the structure of the complex in order to avoid human bias. Model building was performed in a fashion similar to structure calculations from nuclear magnetic resonance (NMR)-spectroscopic data using restrained molecular dynamics. The resulting set of structures of Tat(46-58) in its complex with TAR reveals that all models have converged to a common fold, showing a backbone root mean square deviation (RMSD) of 1.36A. Analysis of the calculated structures suggests that HIV-I Tat forms a hairpin loop in its complex with TAR that shares striking similarity to the hairpin formed by the structure of the bovine immunodeficiency virus Tat protein after TAR binding as determined by NMR studies. The outlined approach is not limited to the Tat-TAR complex modeling, but is also applicable to all molecular complexes with sufficient biochemical and biophysical data available.
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Affiliation(s)
- M J Seewald
- Lehrstuhl für Biopolymere der Universität Bayreuth, Germany
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46
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Schulz A, Escher S, Marx UC, Meyer M, Rösch P, Forssmann WG, Adermann K. Carboxy-terminal extension stabilizes the topological stereoisomers of guanylin. J Pept Res 1998; 52:518-25. [PMID: 9924996 DOI: 10.1111/j.1399-3011.1998.tb01256.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The peptide hormone guanylin constitutes two topological stereoisomers, which are connected through an equilibrium of interconversion. To investigate the importance of amino acid residues in the central region between the inner cysteines and at the carboxy terminus for this isomerism, synthetic derivatives of guanylin were compared by HPLC, 2D1H NMR spectroscopy and by their guanylyl cyclase-C (GC-C)-activating potency. An increase in the central sterical bulk by introduction of diiodo-Tyr9 had virtually no effect on the isomerization kinetics. Compared to guanylin, carboxy-terminal amidation did not affect the equilibrium between the two isoforms either. In contrast, two significantly stabilized isomers were obtained by extending the carboxy terminus of guanylin with one additional leucine resembling the characteristic of human uroguanylin isomers. This effect was intensified by a further Lys-Lys extension, thus revealing that the conformational exchange between the guanylin isomers is dependent on the extent of the sterical hindrance in the carboxy-terminal region of this peptide. Demonstrated by 2D NMR spectroscopy, the separated isomers of the carboxy-terminally extended derivatives of guanylin exhibit unambiguously closely related structures as found originally for guanylin isomers, which are only detectable as a mixture. Because only one of the stabilized guanylin isomers activates guanylyl cyclase-C, the three-dimensional structure of the GC-C-activating guanylin isomer is now defined. The stabilized isoforms of guanylin described in this study represent suitable tools for the separate functional investigation of the GC-C-agonistic isomer of guanylin as well as of its isomeric counterpart.
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Affiliation(s)
- A Schulz
- Niedersächsisches Institut für Peptid-Forschung, Hannover, Germany
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Abstract
Ferredoxins are a group of iron-sulfur proteins for which a wealth of structural and mutational data have recently become available. Previously unknown structures of ferredoxins which are adapted to halophilic, acidophilic or hyperthermophilic environments and new cysteine patterns for cluster ligation and non-cysteine cluster ligation have been described. Site-directed mutagenesis experiments have given insight into factors that influence the geometry, stability, redox potential, electronic properties and electron-transfer reactivity of iron-sulfur clusters.
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Affiliation(s)
- H Sticht
- Lehrstuhl für Struktur und Chemie der Biopolymere, Universität Bayreuth, Germany.
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48
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Marx UC, Klodt J, Meyer M, Gerlach H, Rösch P, Forssmann WG, Adermann K. One peptide, two topologies: structure and interconversion dynamics of human uroguanylin isomers. J Pept Res 1998; 52:229-40. [PMID: 9774236 DOI: 10.1111/j.1399-3011.1998.tb01480.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The peptide hormone uroguanylin stimulates chloride secretion via activation of intestinal guanylyl cyclase C (GC-C). It is characterized by two disulfide bonds in a 1-3/2-4 pattern that causes the existence of two topological stereoisomers of which only one induces intracellular cGMP elevation. To obtain an unambiguous structure-function relationship of the isomers, we determined the solution structure of the separated uroguanylin isoforms using NMR spectroscopy. Both isomers adopt well-defined structures that correspond to those of the isomers of the related peptide guanylin. Furthermore, the structure of the GC-C-activating uroguanylin isomer A closely resembles the structure of the agonistic Escherichia coli heat-stable enterotoxin. Compared with guanylin isomers, the conformational interconversion of uroguanylin isomers is retarded significantly. As judged from chromatography and NMR spectroscopy, both uroguanylin isoforms are stable at low temperatures, but are subject to a slow pH-dependent mutual isomerization at 37 degrees C with an equilibrium isomer ratio of approximately 1:1. The conformational exchange is most likely under the sterical control of the carboxy-terminal leucine. These results imply that GC-C is activated by ligands exhibiting the molecular framework corresponding to the structure of uroguanylin isomer A.
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Affiliation(s)
- U C Marx
- Niedersächsisches Institut für Peptid-Forschung, Hannover, Germany
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49
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Willbold D, Metzger AU, Sticht H, Gallert KC, Voit R, Dank N, Bayer P, Krauss G, Goody RS, Rösch P. Equine infectious anemia virus transactivator is a homeodomain-type protein. J Mol Biol 1998; 277:749-55. [PMID: 9545368 DOI: 10.1006/jmbi.1998.1636] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [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: 11/22/2022]
Abstract
Lentiviral transactivator (Tat) proteins are essential for viral replication. Tat proteins of human immunodeficiency virus type 1 and bovine immunodeficiency virus form complexes with their respective RNA targets (Tat responsive element, TAR), and specific binding of the equine anemia virus (EIAV) Tat protein to a target TAR RNA is suggested by mutational analysis of the TAR RNA. Structural data on equine infectious anemia virus Tat protein reveal a helix-loop-helix-turn-helix limit structure very similar to homeobox domains that are known to bind specifically to DNA. Here we report results of gel-shift and footprinting analysis as well as fluorescence and nuclear magnetic resonance spectroscopy experiments that clearly show that EIAV Tat protein binds to DNA specifically at the long terminal repeat Pu.1 (GTTCCTGTTTT) and AP-1 (TGACGCG) sites, and thus suggest a common mechanism for the action of some of the known lentiviral Tat proteins via the AP-1 initiator site. Complex formation with DNA induces specific shifts of the proton NMR resonances originating from amino acids in the core and basic domains of the protein.
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Affiliation(s)
- D Willbold
- Lehrstuhl für Biopolymere, Universität Bayreuth, Bayreuth, D-95440, Germany
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50
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Marx UC, Adermann K, Bayer P, Meyer M, Forssmann WG, Rösch P. Structure-activity relation of NH2-terminal human parathyroid hormone fragments. J Biol Chem 1998; 273:4308-16. [PMID: 9468478 DOI: 10.1074/jbc.273.8.4308] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [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: 02/06/2023] Open
Abstract
Human parathyroid hormone (hPTH) is involved in the regulation of the calcium level in blood. This hormone function is located in the NH2-terminal 34 amino acids of the 84-amino acid peptide hormone and is transduced via the adenylate cyclase and the phosphatidylinositol signaling pathways. It is well known that truncation of the two NH2-terminal amino acids of the hormone leads to complete loss of in vivo normocalcemic function. To correlate loss of calcium level regulatory activity after stepwise NH2-terminal truncation and solution structure, we studied the conformations of fragments hPTH-(2-37), hPTH-(3-37), and hPTH-(4-37) in comparison to hPTH-(1-37) in aqueous buffer solution under near physiological conditions by circular dichroism spectroscopy, two-dimensional nuclear magnetic resonance spectroscopy, and restrained molecular dynamics calculations. All peptides show helical structures and hydrophobic interactions between Leu-15 and Trp-23 that lead to a defined loop region from His-14 to Ser-17. A COOH-terminal helix from Met-18 to at least Leu-28 was found for all peptides. The helical structure in the NH2-terminal part of the peptides was lost in parallel with the NH2-terminal truncation and can be correlated with the loss of calcium regulatory activity.
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Affiliation(s)
- U C Marx
- Lehrstuhl für Biopolymere, Universität Bayreuth, D-95440 Bayreuth, Federal Republic of Germany
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