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Kaldmäe M, Leppert A, Chen G, Sarr M, Sahin C, Nordling K, Kronqvist N, Gonzalvo-Ulla M, Fritz N, Abelein A, Laίn S, Biverstål H, Jörnvall H, Lane DP, Rising A, Johansson J, Landreh M. High intracellular stability of the spidroin N-terminal domain in spite of abundant amyloidogenic segments revealed by in-cell hydrogen/deuterium exchange mass spectrometry. FEBS J 2019; 287:2823-2833. [PMID: 31815338 PMCID: PMC7383493 DOI: 10.1111/febs.15169] [Citation(s) in RCA: 9] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 11/01/2019] [Accepted: 12/05/2019] [Indexed: 12/22/2022]
Abstract
Proteins require an optimal balance of conformational flexibility and stability in their native environment to ensure their biological functions. A striking example is spidroins, spider silk proteins, which are stored at extremely high concentrations in soluble form, yet undergo amyloid-like aggregation during spinning. Here, we elucidate the stability of the highly soluble N-terminal domain (NT) of major ampullate spidroin 1 in the Escherichia coli cytosol as well as in inclusion bodies containing fibrillar aggregates. Surprisingly, we find that NT, despite being largely composed of amyloidogenic sequences, showed no signs of concentration-dependent aggregation. Using a novel intracellular hydrogen/deuterium exchange mass spectrometry (HDX-MS) approach, we reveal that NT adopts a tight fold in the E. coli cytosol and in this manner conceals its aggregation-prone regions by maintaining a tight fold under crowded conditions. Fusion of NT to the unstructured amyloid-forming Aβ40 peptide, on the other hand, results in the formation of fibrillar aggregates. However, HDX-MS indicates that the NT domain is only partially incorporated into these aggregates in vivo. We conclude that NT is able to control its aggregation to remain functional under the extreme conditions in the spider silk gland.
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Affiliation(s)
- Margit Kaldmäe
- Department of Microbiology, Tumour and Cell Biology, Karolinska Institutet, Biomedicum, Solna, Sweden
| | - Axel Leppert
- Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Division of Neurogeriatrics, Karolinska Institutet, Huddinge, Sweden
| | - Gefei Chen
- Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Division of Neurogeriatrics, Karolinska Institutet, Huddinge, Sweden
| | - Medoune Sarr
- Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Division of Neurogeriatrics, Karolinska Institutet, Huddinge, Sweden
| | - Cagla Sahin
- Department of Microbiology, Tumour and Cell Biology, Karolinska Institutet, Biomedicum, Solna, Sweden
| | - Kerstin Nordling
- Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Division of Neurogeriatrics, Karolinska Institutet, Huddinge, Sweden
| | - Nina Kronqvist
- Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Division of Neurogeriatrics, Karolinska Institutet, Huddinge, Sweden
| | - Marta Gonzalvo-Ulla
- Department of Microbiology, Tumour and Cell Biology, Karolinska Institutet, Biomedicum, Solna, Sweden.,Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Nicolas Fritz
- Department of Microbiology, Tumour and Cell Biology, Karolinska Institutet, Biomedicum, Solna, Sweden
| | - Axel Abelein
- Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Division of Neurogeriatrics, Karolinska Institutet, Huddinge, Sweden
| | - Sonia Laίn
- Department of Microbiology, Tumour and Cell Biology, Karolinska Institutet, Biomedicum, Solna, Sweden
| | - Henrik Biverstål
- Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Division of Neurogeriatrics, Karolinska Institutet, Huddinge, Sweden.,Department of Physical Organic Chemistry, Latvian Institute of Organic Synthesis, Riga, Latvia
| | - Hans Jörnvall
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Biomedicum, Solna, Sweden
| | - David P Lane
- Department of Microbiology, Tumour and Cell Biology, Karolinska Institutet, Biomedicum, Solna, Sweden
| | - Anna Rising
- Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Division of Neurogeriatrics, Karolinska Institutet, Huddinge, Sweden.,Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Jan Johansson
- Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Division of Neurogeriatrics, Karolinska Institutet, Huddinge, Sweden
| | - Michael Landreh
- Department of Microbiology, Tumour and Cell Biology, Karolinska Institutet, Biomedicum, Solna, Sweden
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Ljung K, Andersson M, Floderus L, Nordling K, Corbascio M, Johansson J, Grinnemo KH, Osterholm C, Rising A. P459Human fetal cardiac mesenchymal stromal cells on a novel spider silk 3D scaffold form vessel-like structures and deposit laminins. Cardiovasc Res 2018. [DOI: 10.1093/cvr/cvy060.318] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- K Ljung
- Karolinska Institute, Department of Molecular Medicine and Surgery, Stockholm, Sweden
| | - M Andersson
- Swedish University of Agricultural Sciences, Department of Anatomy, Physiology and Biochemistry, Uppsala, Sweden
| | - L Floderus
- Swedish University of Agricultural Sciences, Department of Anatomy, Physiology and Biochemistry, Uppsala, Sweden
| | - K Nordling
- Swedish University of Agricultural Sciences, Department of Anatomy, Physiology and Biochemistry, Uppsala, Sweden
| | - M Corbascio
- Karolinska Institute, Department of Molecular Medicine and Surgery, Stockholm, Sweden
| | - J Johansson
- Karolinska Institute, Department of Neurobiology, Care Sciences and Society (NVS), Stockholm, Sweden
| | - K H Grinnemo
- Karolinska Institute, Department of Molecular Medicine and Surgery, Stockholm, Sweden
| | - C Osterholm
- Karolinska Institute, Department of Molecular Medicine and Surgery, Stockholm, Sweden
| | - A Rising
- Karolinska Institute, Department of Neurobiology, Care Sciences and Society (NVS), Stockholm, Sweden
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Rising A, Cederlund E, Palmberg C, Uhlhorn H, Gaunitz S, Nordling K, Ågren E, Ihse E, Westermark GT, Tjernberg L, Jörnvall H, Johansson J, Westermark P. Systemic AA amyloidosis in the red fox (Vulpes vulpes). Protein Sci 2017; 26:2312-2318. [PMID: 28791746 DOI: 10.1002/pro.3264] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 07/30/2017] [Accepted: 08/07/2017] [Indexed: 12/14/2022]
Abstract
Amyloid A (AA) amyloidosis occurs spontaneously in many mammals and birds, but the prevalence varies considerably among different species, and even among subgroups of the same species. The Blue fox and the Gray fox seem to be resistant to the development of AA amyloidosis, while Island foxes have a high prevalence of the disease. Herein, we report on the identification of AA amyloidosis in the Red fox (Vulpes vulpes). Edman degradation and tandem MS analysis of proteolyzed amyloid protein revealed that the amyloid partly was composed of full-length SAA. Its amino acid sequence was determined and found to consist of 111 amino acid residues. Based on inter-species sequence comparisons we found four residue exchanges (Ser31, Lys63, Leu71, Lys72) between the Red and Blue fox SAAs. Lys63 seems unique to the Red fox SAA. We found no obvious explanation to how these exchanges might correlate with the reported differences in SAA amyloidogenicity. Furthermore, in contrast to fibrils from many other mammalian species, the isolated amyloid fibrils from Red fox did not seed AA amyloidosis in a mouse model.
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Affiliation(s)
- Anna Rising
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, 750 07, Sweden.,Department of Neurobiology, Care Sciences and Society (NVS), Center for Alzheimer Research, Division of Neurogeriatrics, Karolinska Institutet, Huddinge, 141 57, Sweden
| | - Ella Cederlund
- Department of Medical Biochemistry and Biophysics (MBB), Karolinska Institutet, Stockholm, 171 77, Sweden
| | - Carina Palmberg
- Center of Proteomics Karolinska (PKKI), Karolinska Institutet, Stockholm, 171 77, Sweden
| | - Henrik Uhlhorn
- Department of Pathology and Wildlife Diseases, National Veterinary Institute (SVA), Uppsala, 751 89, Sweden
| | - Stefan Gaunitz
- Department of Neurobiology, Care Sciences and Society (NVS), Center for Alzheimer Research, Division of Neurogeriatrics, Karolinska Institutet, Huddinge, 141 57, Sweden
| | - Kerstin Nordling
- Department of Neurobiology, Care Sciences and Society (NVS), Center for Alzheimer Research, Division of Neurogeriatrics, Karolinska Institutet, Huddinge, 141 57, Sweden
| | - Erik Ågren
- Department of Pathology and Wildlife Diseases, National Veterinary Institute (SVA), Uppsala, 751 89, Sweden
| | - Elisabet Ihse
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, 751 85, Sweden
| | | | - Lars Tjernberg
- Department of Neurobiology, Care Sciences and Society (NVS), Center for Alzheimer Research, Division of Neurogeriatrics, Karolinska Institutet, Huddinge, 141 57, Sweden
| | - Hans Jörnvall
- Department of Medical Biochemistry and Biophysics (MBB), Karolinska Institutet, Stockholm, 171 77, Sweden
| | - Jan Johansson
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, 750 07, Sweden.,Department of Neurobiology, Care Sciences and Society (NVS), Center for Alzheimer Research, Division of Neurogeriatrics, Karolinska Institutet, Huddinge, 141 57, Sweden
| | - Per Westermark
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, 751 85, Sweden
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Otikovs M, Andersson M, Jia Q, Nordling K, Meng Q, Andreas LB, Pintacuda G, Johansson J, Rising A, Jaudzems K. Degree of Biomimicry of Artificial Spider Silk Spinning Assessed by NMR Spectroscopy. Angew Chem Int Ed Engl 2017; 56:12571-12575. [PMID: 28791761 DOI: 10.1002/anie.201706649] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [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: 06/30/2017] [Indexed: 01/29/2023]
Abstract
Biomimetic spinning of artificial spider silk requires that the terminal domains of designed minispidroins undergo specific structural changes in concert with the β-sheet conversion of the repetitive region. Herein, we combine solution and solid-state NMR methods to probe domain-specific structural changes in the NT2RepCT minispidroin, which allows us to assess the degree of biomimicry of artificial silk spinning. In addition, we show that the structural effects of post-spinning procedures can be examined. By studying the impact of NT2RepCT fiber drying, we observed a reversible beta-to-alpha conversion. We think that this approach will be useful for guiding the optimization of artificial spider silk fibers.
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Affiliation(s)
- Martins Otikovs
- Latvian Institute of Organic Synthesis, Aizkraukles 21, 1006, Riga, Latvia
| | - Marlene Andersson
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Box 7011, 750 07, Uppsala, Sweden
| | - Qiupin Jia
- Institute of Biological Sciences and Biotechnology, Donghua University, 201620, Shanghai, China
| | - Kerstin Nordling
- Department of Neurobiology, Care Sciences and Society (NVS), Center for Alzheimer Research, Karolinska Institutet, Novum, 141 57, Huddinge, Sweden
| | - Qing Meng
- Institute of Biological Sciences and Biotechnology, Donghua University, 201620, Shanghai, China
| | - Loren B Andreas
- Centre de RMN à Très Hauts Champs, Institut des Sciences Analytiques (UMR 5280-CNRS, ENS Lyon, UCB Lyon 1), Université de Lyon, 5 rue de la Doua, 69100, Villeurbanne, France
| | - Guido Pintacuda
- Centre de RMN à Très Hauts Champs, Institut des Sciences Analytiques (UMR 5280-CNRS, ENS Lyon, UCB Lyon 1), Université de Lyon, 5 rue de la Doua, 69100, Villeurbanne, France
| | - Jan Johansson
- Department of Neurobiology, Care Sciences and Society (NVS), Center for Alzheimer Research, Karolinska Institutet, Novum, 141 57, Huddinge, Sweden
| | - Anna Rising
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Box 7011, 750 07, Uppsala, Sweden.,Department of Neurobiology, Care Sciences and Society (NVS), Center for Alzheimer Research, Karolinska Institutet, Novum, 141 57, Huddinge, Sweden
| | - Kristaps Jaudzems
- Latvian Institute of Organic Synthesis, Aizkraukles 21, 1006, Riga, Latvia
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Otikovs M, Andersson M, Jia Q, Nordling K, Meng Q, Andreas LB, Pintacuda G, Johansson J, Rising A, Jaudzems K. Degree of Biomimicry of Artificial Spider Silk Spinning Assessed by NMR Spectroscopy. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201706649] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Martins Otikovs
- Latvian Institute of Organic Synthesis Aizkraukles 21 1006 Riga Latvia
| | - Marlene Andersson
- Department of Anatomy, Physiology and Biochemistry Swedish University of Agricultural Sciences Box 7011 750 07 Uppsala Sweden
| | - Qiupin Jia
- Institute of Biological Sciences and Biotechnology Donghua University 201620 Shanghai China
| | - Kerstin Nordling
- Department of Neurobiology Care Sciences and Society (NVS) Center for Alzheimer Research Karolinska Institutet Novum 141 57 Huddinge Sweden
| | - Qing Meng
- Institute of Biological Sciences and Biotechnology Donghua University 201620 Shanghai China
| | - Loren B. Andreas
- Centre de RMN à Très Hauts Champs Institut des Sciences Analytiques (UMR 5280-CNRS, ENS Lyon, UCB Lyon 1) Université de Lyon 5 rue de la Doua 69100 Villeurbanne France
| | - Guido Pintacuda
- Centre de RMN à Très Hauts Champs Institut des Sciences Analytiques (UMR 5280-CNRS, ENS Lyon, UCB Lyon 1) Université de Lyon 5 rue de la Doua 69100 Villeurbanne France
| | - Jan Johansson
- Department of Neurobiology Care Sciences and Society (NVS) Center for Alzheimer Research Karolinska Institutet Novum 141 57 Huddinge Sweden
| | - Anna Rising
- Department of Anatomy, Physiology and Biochemistry Swedish University of Agricultural Sciences Box 7011 750 07 Uppsala Sweden
- Department of Neurobiology Care Sciences and Society (NVS) Center for Alzheimer Research Karolinska Institutet Novum 141 57 Huddinge Sweden
| | - Kristaps Jaudzems
- Latvian Institute of Organic Synthesis Aizkraukles 21 1006 Riga Latvia
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6
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Otikovs M, Chen G, Nordling K, Landreh M, Meng Q, Jörnvall H, Kronqvist N, Rising A, Johansson J, Jaudzems K. Back Cover: Diversified Structural Basis of a Conserved Molecular Mechanism for pH-Dependent Dimerization in Spider Silk N-Terminal Domains (ChemBioChem 12/2015). Chembiochem 2015. [DOI: 10.1002/cbic.201590036] [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]
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7
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Otikovs M, Chen G, Nordling K, Landreh M, Meng Q, Jörnvall H, Kronqvist N, Rising A, Johansson J, Jaudzems K. Diversified Structural Basis of a Conserved Molecular Mechanism for pH-Dependent Dimerization in Spider Silk N-Terminal Domains. Chembiochem 2015; 16:1720-4. [DOI: 10.1002/cbic.201500263] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Indexed: 11/11/2022]
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Andersson M, Chen G, Otikovs M, Landreh M, Nordling K, Kronqvist N, Westermark P, Jörnvall H, Knight S, Ridderstråle Y, Holm L, Meng Q, Jaudzems K, Chesler M, Johansson J, Rising A. Carbonic anhydrase generates CO2 and H+ that drive spider silk formation via opposite effects on the terminal domains. PLoS Biol 2014; 12:e1001921. [PMID: 25093327 PMCID: PMC4122339 DOI: 10.1371/journal.pbio.1001921] [Citation(s) in RCA: 128] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 06/26/2014] [Indexed: 11/18/2022] Open
Abstract
Spider silk fibers are produced from soluble proteins (spidroins) under ambient conditions in a complex but poorly understood process. Spidroins are highly repetitive in sequence but capped by nonrepetitive N- and C-terminal domains (NT and CT) that are suggested to regulate fiber conversion in similar manners. By using ion selective microelectrodes we found that the pH gradient in the silk gland is much broader than previously known. Surprisingly, the terminal domains respond in opposite ways when pH is decreased from 7 to 5: Urea denaturation and temperature stability assays show that NT dimers get significantly stabilized and then lock the spidroins into multimers, whereas CT on the other hand is destabilized and unfolds into ThT-positive β-sheet amyloid fibrils, which can trigger fiber formation. There is a high carbon dioxide pressure (pCO2) in distal parts of the gland, and a CO2 analogue interacts with buried regions in CT as determined by nuclear magnetic resonance (NMR) spectroscopy. Activity staining of histological sections and inhibition experiments reveal that the pH gradient is created by carbonic anhydrase. Carbonic anhydrase activity emerges in the same region of the gland as the opposite effects on NT and CT stability occur. These synchronous events suggest a novel CO2 and proton-dependent lock and trigger mechanism of spider silk formation.
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Affiliation(s)
- Marlene Andersson
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Gefei Chen
- Institute of Biological Sciences and Biotechnology, Donghua University, Shanghai, People's Republic of China
| | - Martins Otikovs
- Department of Physical Organic Chemistry, Latvian Institute of Organic Synthesis, Riga, Latvia
| | - Michael Landreh
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Kerstin Nordling
- Department of Neurobiology, Care Sciences and Society (NVS), Karolinska Institutet, Stockholm, Sweden
| | - Nina Kronqvist
- Department of Neurobiology, Care Sciences and Society (NVS), Karolinska Institutet, Stockholm, Sweden
| | - Per Westermark
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Hans Jörnvall
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Stefan Knight
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Yvonne Ridderstråle
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Lena Holm
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Qing Meng
- Institute of Biological Sciences and Biotechnology, Donghua University, Shanghai, People's Republic of China
- * E-mail: (J.J.); (Q.M.); (A.R.)
| | - Kristaps Jaudzems
- Department of Physical Organic Chemistry, Latvian Institute of Organic Synthesis, Riga, Latvia
| | - Mitchell Chesler
- Departments of Neurosurgery, Physiology and Neuroscience, New York University School of Medicine, New York, New York, United States of America
| | - Jan Johansson
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden
- Department of Neurobiology, Care Sciences and Society (NVS), Karolinska Institutet, Stockholm, Sweden
- Institute of Mathematics and Natural Sciences, Tallinn University, Tallinn, Estonia
- * E-mail: (J.J.); (Q.M.); (A.R.)
| | - Anna Rising
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden
- Department of Neurobiology, Care Sciences and Society (NVS), Karolinska Institutet, Stockholm, Sweden
- * E-mail: (J.J.); (Q.M.); (A.R.)
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Kronqvist N, Otikovs M, Chmyrov V, Chen G, Andersson M, Nordling K, Landreh M, Sarr M, Jörnvall H, Wennmalm S, Widengren J, Meng Q, Rising A, Otzen D, Knight SD, Jaudzems K, Johansson J. Sequential pH-driven dimerization and stabilization of the N-terminal domain enables rapid spider silk formation. Nat Commun 2014; 5:3254. [DOI: 10.1038/ncomms4254] [Citation(s) in RCA: 105] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 01/14/2014] [Indexed: 11/09/2022] Open
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Hedhammar M, Bramfeldt H, Baris T, Widhe M, Askarieh G, Nordling K, Aulock SV, Johansson J. Sterilized recombinant spider silk fibers of low pyrogenicity. Biomacromolecules 2010; 11:953-9. [PMID: 20235574 DOI: 10.1021/bm9014039] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
We have recently shown that it is possible to recombinantly produce a miniature spider silk protein, 4RepCT, that spontaneously self-assembles into mechanically stable macroscopic fibers (Stark, M.; Grip, S.; Rising, A.; Hedhammar, M.; Engstrom, W.; Hjalm, G.; Johansson, J. Macroscopic fibers self-assembled from recombinant miniature spider silk proteins. Biomacromolecules 2007, 8 (5), 1695-1701). When produced as a soluble fusion protein (with thioredoxin) in Escherichia coli , the spider silk protein can be subjected to several purification steps without aggregating. Here, combined purification and endotoxin removal is achieved using a simple cell wash procedure, protein affinity purification, and LPS depletion. No toxic chemicals were included in the process and the protein retained its ability to self-assemble into fibers. With this method, fibers with pyrogenicity corresponding to less than 1 EU/mg could be recovered. Moreover, the fibers could be sterilized through autoclaving with retained morphology, structure, and mechanical properties. This implies that this recombinant silk is suitable for usage as biomaterial, which is further supported by data showing that the fibers allow growth of human primary fibroblasts.
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Affiliation(s)
- My Hedhammar
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala Biomedical Centre, SE-751 23 Uppsala, Sweden.
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Fredriksson C, Hedhammar M, Feinstein R, Nordling K, Kratz G, Johansson J, Huss F, Rising A. Tissue Response to Subcutaneously Implanted Recombinant Spider Silk: An in Vivo Study. Materials 2009. [PMCID: PMC5513568 DOI: 10.3390/ma2041908] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Spider silk is an interesting biomaterial for medical applications. Recently, a method for production of recombinant spider silk protein (4RepCT) that forms macroscopic fibres in physiological solution was developed. Herein, 4RepCT and MersilkTM (control) fibres were implanted subcutaneously in rats for seven days, without any negative systemic or local reactions. The tissue response, characterised by infiltration of macrophages and multinucleated cells, was similar with both fibres, while only the 4RepCT-fibres supported ingrowth of fibroblasts and newly formed capillaries. This in vivo study indicates that 4RepCT-fibres are well tolerated and could be used for medical applications, e.g., tissue engineering.
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Affiliation(s)
- Camilla Fredriksson
- Laboratory for Experimental Plastic Surgery, Institution of Clinical and Experimental Medicine, Faculty of Health Science, Linköpings Universitet, 581 83 Linköping, Sweden; E-Mail: (C.F.)
- Berzelius Clinical Research Center, Berzelius Science Park, 582 25 Linköping, Sweden
| | - My Hedhammar
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Box 575, the Biomedical Centre, 751 23 Uppsala, Sweden; E-Mail: (M.H.); (K.N.); (J.J.)
| | - Ricardo Feinstein
- National Veterinary Institute, 751 89 Uppsala, Sweden; E-Mail: (R.F.)
| | - Kerstin Nordling
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Box 575, the Biomedical Centre, 751 23 Uppsala, Sweden; E-Mail: (M.H.); (K.N.); (J.J.)
| | - Gunnar Kratz
- Department of Plastic-, Hand-, and Burn Surgery, University Hospital of Linköping, 581 85 Linköping, Sweden; E-Mail: (G.K.); (F.H.)
| | - Jan Johansson
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Box 575, the Biomedical Centre, 751 23 Uppsala, Sweden; E-Mail: (M.H.); (K.N.); (J.J.)
| | - Fredrik Huss
- Department of Plastic-, Hand-, and Burn Surgery, University Hospital of Linköping, 581 85 Linköping, Sweden; E-Mail: (G.K.); (F.H.)
| | - Anna Rising
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Box 575, the Biomedical Centre, 751 23 Uppsala, Sweden; E-Mail: (M.H.); (K.N.); (J.J.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +46-18-471-4019; Fax: +46-18-550-762
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Fitzen M, Alvelius G, Nordling K, Jörnvall H, Bergman T, Johansson J. Peptide-binding specificity of the prosurfactant protein C Brichos domain analyzed by electrospray ionization mass spectrometry. Rapid Commun Mass Spectrom 2009; 23:3591-3598. [PMID: 19844966 DOI: 10.1002/rcm.4282] [Citation(s) in RCA: 14] [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] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The C-terminal domain of lung surfactant protein C (CTC) precursor (proSP-C) is involved in folding of the transmembrane segment of proSP-C. CTC includes a Brichos domain with homologs in cancer- and dementia-associated proteins. Mutations in the Brichos domain cause misfolding of proSP-C and hence amyloid fibril formation in interstitial lung disease. Electrospray ionization mass spectrometry (ESI-MS) with collision-induced dissociation (CID) experiments was applied to study non-covalent interactions between human recombinant CTC or its Brichos domain, and SP-C analogs, homotripeptides and peptides designed to model amyloid fibril formation. The results show that the Brichos domain contains the peptide-binding function of CTC. In titration experiments, apparent dissociation constants (KD) were in the micromolar range where triple-valine showed the lowest KD and triple-tyrosine the highest. Non-hydrophobic peptides failed to form complexes with Brichos. CID revealed that complexes with aromatic peptide ligands are more stable in the gas phase than complexes with non-aromatic ligands. The Brichos domain was also shown to bind fibril-forming peptides containing aromatic/hydrophobic residues.
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Affiliation(s)
- Michael Fitzen
- Department of Medical Biochemistry and Biophysics, Division of Chemistry I, Karolinska Institutet, SE-171 77 Stockholm, Sweden
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Eriksson M, von Euler H, Ekman E, Nordling K, Häggström J, Johansson J. Surfactant Protein C in Canine Pulmonary Fibrosis. J Vet Intern Med 2009; 23:1170-4. [DOI: 10.1111/j.1939-1676.2009.0380.x] [Citation(s) in RCA: 5] [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: 11/29/2022] Open
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14
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Johansson H, Eriksson M, Nordling K, Presto J, Johansson J. The Brichos domain of prosurfactant protein C can hold and fold a transmembrane segment. Protein Sci 2009; 18:1175-82. [PMID: 19472327 DOI: 10.1002/pro.123] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [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: 11/07/2022]
Abstract
Prosurfactant protein C (proSP-C) is a 197-residue integral membrane protein, in which the C-terminal domain (CTC, positions 59-197) is localized in the endoplasmic reticulum (ER) lumen and contains a Brichos domain (positions 94-197). Mature SP-C corresponds largely to the transmembrane (TM) region of proSP-C. CTC binds to SP-C, provided that it is in nonhelical conformation, and can prevent formation of intracellular amyloid-like inclusions of proSP-C that harbor mutations linked to interstitial lung disease (ILD). Herein it is shown that expression of proSP-C (1-58), that is, the N-terminal propeptide and the TM region, in HEK293 cells results in virtually no detectable protein, while coexpression of CTC in trans yields SDS-soluble monomeric proSP-C (1-58). Recombinant human (rh) CTC binds to cellulose-bound peptides derived from the nonpolar TM region, but not the polar cytosolic part, of proSP-C, and requires >/=5-residues for maximal binding. Binding of rhCTC to a nonhelical peptide derived from SP-C results in alpha-helix formation provided that it contains a long TM segment. Finally, rhCTC and rhCTC Brichos domain shows very similar substrate specificities, but rhCTC(L188Q), a mutation linked to ILD is unable to bind all peptides analyzed. These data indicate that the Brichos domain of proSP-C is a chaperone that induces alpha-helix formation of an aggregation-prone TM region.
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Affiliation(s)
- Hanna Johansson
- Department of Anatomy, Physiology and Biochemistry, SLU, The Biomedical Centre, Uppsala, Sweden
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15
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Nerelius C, Gustafsson M, Nordling K, Larsson A, Johansson J. Anti-amyloid activity of the C-terminal domain of proSP-C against amyloid beta-peptide and medin. Biochemistry 2009; 48:3778-86. [PMID: 19281242 DOI: 10.1021/bi900135c] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Amyloid fibrils are found in approximately 25 different diseases, including Alzheimer's disease. Lung surfactant protein C (SP-C) forms fibrils in association with pulmonary disease. It was recently found that the C-terminal domain of proSP-C (CTC), which is localized to the endoplasmic reticulum (ER) lumen, protects the transmembrane (TM) part of (pro)SP-C from aggregation into amyloid until it has a folded into an alpha-helix. CTC appears to have a more general anti-amyloid effect by also acting on TM regions of other proteins. Here we investigate interactions of CTC with the amyloid beta-peptide (Abeta) associated with Alzheimer's disease and medin, a peptide that forms fibrils in the most common form of human amyloid. CTC prevents fibril formation in Abeta and medin and forms a complex with Abeta oligomers, as judged by size-exclusion chromatography and electrospray ionization mass spectrometry. These data suggest that CTC functions as a chaperone that acts preferentially against unfolded TM segments and structural motifs found during amyloid fibril formation, a mechanism that may be exploited in forming a basis for future anti-amyloid therapy.
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Affiliation(s)
- Charlotte Nerelius
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, The Biomedical Centre, 751 23 Uppsala, Sweden
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16
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Johansson H, Nerelius C, Nordling K, Johansson J. Preventing amyloid formation by catching unfolded transmembrane segments. J Mol Biol 2009; 389:227-9. [PMID: 19376131 DOI: 10.1016/j.jmb.2009.04.021] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2009] [Revised: 03/19/2009] [Accepted: 04/10/2009] [Indexed: 10/20/2022]
Abstract
A subset of protein misfolding diseases, including, for example, Alzheimer's disease, is associated with the formation of highly insoluble amyloid fibrils with a beta-sheet structure. The amyloidogenic human lung surfactant protein C (SP-C) is generated from SP-C precursor, which has a C-terminal domain (CTC) that prevents SP-C amyloid fibril formation. Analysis of the substrate specificity of CTC reveals that it binds to all amino acid residues that promote membrane insertion, provided that they are in a nonhelical conformation. In line with this unexpectedly general substrate specificity, the anti-amyloid function of CTC extends to a transmembrane segment other than that of (pro)SP-C, namely, the amyloid beta-peptide associated with Alzheimer's disease. These findings indicate that CTC is the first known chaperone to be directed towards nonhelical transmembrane segments and that it may be employed for the development of new diagnostics or anti-amyloid therapies.
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Affiliation(s)
- H Johansson
- Department of Anatomy, Physiology, and Biochemistry, SLU, The Biomedical Center, 75123 Uppsala, Sweden
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17
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Hedhammar M, Rising A, Grip S, Martinez AS, Nordling K, Casals C, Stark M, Johansson J. Structural properties of recombinant nonrepetitive and repetitive parts of major ampullate spidroin 1 from Euprosthenops australis: implications for fiber formation. Biochemistry 2008; 47:3407-17. [PMID: 18293938 DOI: 10.1021/bi702432y] [Citation(s) in RCA: 107] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Spider dragline silk proteins, spidroins, have a tripartite composition; a nonrepetitive N-terminal domain, a central repetitive region built up from many iterated poly-Ala and Gly rich blocks, and a C-terminal nonrepetitive domain. It is generally believed that the repetitive region forms intermolecular contacts in the silk fibers, while precise functions of the terminal domains have not been established. Herein, thermal, pH, and salt effects on the structure and aggregation and/or polymerization of recombinant N- and C-terminal domains, a repetitive segment containing four poly-Ala and Gly rich coblocks, and combinations thereof were studied. The N- and C-terminal domains have mainly alpha-helical structure, and interestingly, both form homodimers. Dimerization of the end domains allows spidroin multimerization independent of the repetitive part. Reduction of an intersubunit disulfide in the C-terminal domain lowers the thermal stability but does not affect dimerization. The repetitive region shows helical secondary structure but appears to lack stable folded structure. A protein composed of this repetitive region linked to the C-terminal domain has a mainly alpha-helical folded structure but shows an abrupt transition to beta-sheet structures upon heating. At room temperature, this protein self-assembles into macroscopic fibers within minutes. The secondary structures of none of the domains are altered by pH or salt. However, high concentrations of phosphate affect the tertiary structure and accelerate the aggregation propensity of the repetitive region. Implications of these results for dragline spidroin behavior in solution and silk fiber formation are discussed.
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Affiliation(s)
- My Hedhammar
- Department of Anatomy, Physiology and Biochemistry, Biomedical Centre, Swedish University of Agricultural Sciences, SE-751 23 Uppsala, Sweden.
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18
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Casals C, Johansson H, Saenz A, Gustafsson M, Alfonso C, Nordling K, Johansson J. C-terminal, endoplasmic reticulum-lumenal domain of prosurfactant protein C - structural features and membrane interactions. FEBS J 2008; 275:536-47. [DOI: 10.1111/j.1742-4658.2007.06220.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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19
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Sharma S, Kathuria PC, Gupta CK, Nordling K, Ghosh B, Singh AB. Total serum immunoglobulin E levels in a case-control study in asthmatic/allergic patients, their family members, and healthy subjects from India. Clin Exp Allergy 2007; 36:1019-27. [PMID: 16911358 DOI: 10.1111/j.1365-2222.2006.02525.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Total immunoglobulin E (IgE) is an important indicator of allergic disorders. However, its role in allergic patients in India has not been evaluated in relation to atopic status for a reference range as compared with healthy subjects. OBJECTIVE The aim of the study was to establish serum IgE levels in a diseased group, study its relationship with atopy, and to compare the same with healthy volunteers in Indian subjects. METHODS Four hundred and eighty asthmatics/allergic patients, 100 first-degree relatives of asthmatics, and 120 unrelated normal healthy volunteers from Delhi region were recruited for the study. Atopy was established by family history and skin test to common indigenous allergens and, total and specific IgE measurements. Statistical analysis was performed with the help of SPSS software program. RESULTS The mean IgE levels were the highest in asthmatic patients and the lowest in the control healthy group. IgE was significantly high in the male than the female healthy volunteers (P<0.05), but not in the diseased group. Prosopis juliflora among pollen allergens and Alternaria alternata among fungal allergens were important sensitizers in allergic patients with 34.7% and 17.7% skin positivity, respectively. Atopic status and asthma were found to be the best predictor of IgE, which was highly significant (r(2)=0.239, P<0.00001). However, at 95% confidence interval as many as 50% of asthmatic patients had their IgE values in the normal range. CONCLUSION The IgE levels in Indian allergic patients is significantly related to atopy, but due to wide overlap of IgE levels in patients and healthy subjects, its diagnostic significance in Indian population seems to be limited.
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Affiliation(s)
- S Sharma
- Institute of Genomics & Integrative Biology, Delhi, India
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20
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Johansson H, Nordling K, Weaver TE, Johansson J. The Brichos Domain-containing C-terminal Part of Pro-surfactant Protein C Binds to an Unfolded Poly-Val Transmembrane Segment. J Biol Chem 2006; 281:21032-21039. [PMID: 16709565 DOI: 10.1074/jbc.m603001200] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [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: 11/06/2022] Open
Abstract
Native lung surfactant protein C (SP-C) is a 4.2-kDa acylpeptide that associates with alveolar surfactant phospholipids via a transmembrane alpha-helix. This helix contains mainly Val, although poly-Val is inefficient in helix formation, and helical SP-C can spontaneously convert to beta-sheet aggregates and amyloid-like fibrils. SP-C is cleaved out from a 21-kDa integral membrane protein, proSP-C, in the alveolar type II cell. Recently several mutations localized in the endoplasmic reticulum-lumenal (C-terminal) part of proSP-C (CTproSP-C) have been associated with intracellular accumulation of toxic forms of proSP-C, low levels of mature SP-C, and development of interstitial lung disease. CTproSP-C contains a approximately 100-residue Brichos domain of unknown function that is also found in other membrane proteins associated with amyloid formation, dementia, and cancer. Here we find that recombinant CTproSP-C binds lipid-associated SP-C, which is in beta-strand conformation, and that this interaction results in an increased helical content. In contrast, CTproSP-C does not bind alpha-helical SP-C. Recombinant CTproSP-C(L188Q), a mutation associated with interstitial lung disease, shows secondary and quaternary structures similar to those of wild type CTproSP-C but is unable to bind lipid-associated beta-strand SP-C. Transfection of CTproSP-C into HEK293 cells that express proSP-C(L188Q) increases the amount of proSP-C protein, whereas no effect is seen on cells expressing wild type proSP-C. These findings suggest that CTproSP-C binds nonhelical SP-C and thereby prevents beta-sheet aggregation and that mutations in CTproSP-C can interfere with this function.
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Affiliation(s)
- Hanna Johansson
- Department of Molecular Biosciences, Swedish University of Agricultural Sciences, The Biomedical Centre, S-751 23 Uppsala, Sweden
| | - Kerstin Nordling
- Department of Molecular Biosciences, Swedish University of Agricultural Sciences, The Biomedical Centre, S-751 23 Uppsala, Sweden
| | - Timothy E Weaver
- Division of Pulmonary Biology, Cincinnati Children's Research Foundation, Cincinnati, Ohio 45229-3039
| | - Jan Johansson
- Department of Molecular Biosciences, Swedish University of Agricultural Sciences, The Biomedical Centre, S-751 23 Uppsala, Sweden.
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Larsson H, Akerud P, Nordling K, Raub-Segall E, Claesson-Welsh L, Björk I. A novel anti-angiogenic form of antithrombin with retained proteinase binding ability and heparin affinity. J Biol Chem 2001; 276:11996-2002. [PMID: 11278631 DOI: 10.1074/jbc.m010170200] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [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
Latent antithrombin, an inactive antithrombin form with low heparin affinity, has previously been shown to efficiently inhibit angiogenesis and tumor growth. We now show that heat treatment similar to that used for preparation of latent antithrombin also transforms antithrombin to another form, which we denote prelatent, with potent anti-angiogenic and anti-tumor activity but with retained proteinase- and heparin-binding properties. The ability of prelatent antithrombin to inhibit angiogenesis is presumably due to a limited conformational change, which may partially resemble that in latent antithrombin. Such a change is evidenced by a different cleavage pattern of prelatent than of native antithrombin by nontarget proteinases. Prelatent antithrombin exerts its anti-angiogenic effect by a similar mechanism as latent antithrombin, i.e. by inhibiting focal adhesion formation and focal adhesion kinase activity, thereby leading to decreased proliferation of endothelial cells. The proteinase inhibitory fractions in commercial antithrombin preparations, which have been heat treated during production, also have anti-angiogenic activity, comparable with that of the prelatent antithrombin form.
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Affiliation(s)
- H Larsson
- Department of Genetics and Pathology, Rudbeck Laboratory, Uppsala University, SE-751 85 Uppsala, Sweden
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22
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Abstract
Heparin and heparan sulfate are structurally related polysaccharides with a variety of biological effects/functions. Most of these effects are due to interactions, of varying specificity, between the negatively charged polysaccharide chains and proteins. While such interactions generally involve a single saccharide domain of decasaccharide size or less, ternary complexes of two protein molecules binding to separate domains on a single polysaccharide chain are known to occur. To facilitate studies on domain organization and its importance for biological function a strategy was developed to chemically conjugate defined heparin oligomers in linear and chemoselective fashion. The procedure requires that the oligosaccharide to provide the reducing-terminal domain of the conjugate is generated by lyase degradation of a parent polysaccharide, whereas the nonreducing-terminal domain is obtained through deaminative cleavage with nitrous acid. The applicability of the method was demonstrated by constructing a conjugate composed of two heparin 12-mers, of which the reducing-terminal component contained the antithrombin-binding region, whereas the nonreducing-terminal domain did not. Contrary to any of the unconjugated oligomers, the product was found to efficiently promote the inactivation of thrombin by antithrombin.
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Affiliation(s)
- J Rong
- Department of Medical Biochemistry and Microbiology, Box 582, The Biomedical Center, Uppsala University, S-751 23 Uppsala, Sweden
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Björk I, Nordling K, Raub-Segall E, Hellman U, Olson ST. Inactivation of papain by antithrombin due to autolytic digestion: a model of serpin inactivation of cysteine proteinases. Biochem J 1998; 335 ( Pt 3):701-9. [PMID: 9794814 PMCID: PMC1219835 DOI: 10.1042/bj3350701] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Cross-class inhibition of cysteine proteinases by serpins differs from serpin inhibition of serine proteinases primarily in that no stable serpin-cysteine proteinase complex can be demonstrated. This difference in reaction mechanism was elucidated by studies of the inactivation of the cysteine proteinases, papain and cathepsin L, by the serpin antithrombin. The two proteinases were inactivated with second-order rate constants of (1.6+/-0.1)x10(3) and (8.6+/-0. 4)x10(2) M-1.s-1 respectively. An antithrombin to papain inactivation stoichiometry of approximately 3 indicated extensive cleavage of the inhibitor concurrent with enzyme inactivation, a behaviour verified by SDS/PAGE. N-terminal sequence analyses showed cleavage predominantly at the P2-P1 bond, but also at the P2'-P3' bond of antithrombin. The papain band in SDS/PAGE progressively disappeared on reaction of the enzyme with increasing amounts of antithrombin, but no band representing a stable antithrombin-papain complex appeared. SDS/PAGE with 125I-labelled papain showed that the disappearance of papain was caused by cleavage of the enzyme into small fragments. These results suggest a mechanism in which papain attacks a peptide bond in the reactive-bond loop of antithrombin adjacent to that involved in serine proteinase inhibition. The reaction proceeds, similarly to that between serpins and serine proteinases, to form an inactive acyl-intermediate complex, although with the substrate pathway dominating in the papain reaction. In this complex, papain is highly susceptible to proteolysis and is degraded by still active papain, which greatly decreases the lifetime of the complex and results in liberation of fragmented, inactive enzyme. This model may have relevance also for the inactivation of physiologically or pathologically important cysteine proteinases by serpins.
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Affiliation(s)
- I Björk
- Department of Veterinary Medical Chemistry, Swedish University of Agricultural Sciences, Uppsala Biomedical Center, Box 575, SE-751 23 Uppsala, Sweden.
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Scopinaro F, Schillaci O, Ussof W, Nordling K, Capoferro R, De Vincentis G, Danieli R, Ierardi M, Picardi V, Tavolaro R, Colella AC. A three center study on the diagnostic accuracy of 99mTc-MIBI scintimammography. Anticancer Res 1997; 17:1631-4. [PMID: 9179208] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
In order to assess specificity and sensitivity of the prone scintimammography (PSM) in a large series with 99m-Tc MIBI, we performed a three-center study; 420 patients were studied; after mammography all the patients were submitted to PSM and biopsy and/or operation. PSM was considered positive if hot spot within the breast was observed. In palpable masses sensitivity was 0.98 and specificity 0.89, non palpable masses showed a sensitivity of 0.62 and a specificity of 0.91. When the cancers were stratified for T category the sensitivity was 0.28 in T1a 0.26 in the group of T1a carcinomas, 0.56 in T1b 0.95 in T1c and 0.97 T2 tumors. Physical factors such as attenuation. Compton scattering from chest, as well as biological factors have a role in breast tumor imaging. In the tumors smaller than 1 cm biological factors are probably involved too.
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Affiliation(s)
- F Scopinaro
- Department of Experimental Medicine, University La Sapienza, Rome, Italy
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25
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Nordling K, Björk I. Identification of an epitope in antithrombin appearing on insertion of the reactive-bond loop into the A beta-sheet. Biochemistry 1996; 35:10436-40. [PMID: 8756699 DOI: 10.1021/bi9603579] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [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: 02/02/2023]
Abstract
Previous work has shown that insertion of the reactive-bond loop of antithrombin into the main beta-sheet of the inhibitor, the A sheet, leads to exposure of epitopes that are not present in intact antithrombin. Identical epitopes are exposed in antithrombin-proteinase complexes, inferring that the reactive-bond loop is inserted into the A beta-sheet also in these complexes. Loop insertion thus presumably is involved in the mechanism of inhibition of target proteinases. In this work, we have identified a linear epitope in bovine antithrombin that reacts with antibodies specific for loop-inserted forms of the inhibitor. This epitope is a hexapeptide sequence comprising residues 342-347, Glu-Asp-Leu-Phe-Ser-Pro, and is located on the surface of the protein just carboxy-terminal of helix I. The Phe residue of this epitope is highly conserved in members of the serpin superfamily and appears to stabilize the region of the epitope in antithrombin and other serpins by interacting with the protein core. The conformational change involving expansion of the A beta-sheet following insertion of the reactive-bond loop is presumably transmitted through this Phe residue to the epitope region, thereby rendering this region accessible to antibodies.
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Affiliation(s)
- K Nordling
- Department of Veterinary Medical Chemistry, Swedish University of Agricultural Sciences, Uppsala Biomedical Center, Sweden
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Björk I, Nordling K, Olson ST. Immunologic evidence for insertion of the reactive-bond loop of antithrombin into the A beta-sheet of the inhibitor during trapping of target proteinases. Biochemistry 1993; 32:6501-5. [PMID: 7687144 DOI: 10.1021/bi00077a002] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Identical or highly similar antigenic determinants, not present in the intact inhibitor, were induced in antithrombin on cleavage of the reactive bond, on formation of a complex between antithrombin and a synthetic reactive-loop tetradecapeptide, and on partial denaturation of antithrombin at low concentrations of guanidinium chloride. Previous studies indicate that the common structural feature of these three modified forms of antithrombin is that the region of the reactive-bond loop on the amino-terminal side of the reactive bond, or the corresponding synthetic peptide, is inserted as a middle strand in the main beta-sheet of the inhibitor, the A sheet. The new epitopes in the three modified antithrombin forms therefore most likely are exposed as a result of this insertion. Identical or highly similar epitopes were exposed also in complexes between antithrombin and thrombin or factor Xa, strongly suggesting that a substantial segment of the reactive-bond loop is inserted into the A sheet also in these complexes. In contrast, the new epitopes were not exposed in antithrombin on binding of heparin, implying that the conformational change induced by heparin does not involve such loop insertion. These results provide the first experimental verification of recent hypotheses that insertion of the reactive-bond loop of serpins into the A beta-sheet is involved in the binding of target proteinases.
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Affiliation(s)
- I Björk
- Department of Veterinary Medical Chemistry, Swedish University of Agricultural Sciences, Uppsala
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Björk I, Nordling K, Larsson I, Olson ST. Kinetic characterization of the substrate reaction between a complex of antithrombin with a synthetic reactive-bond loop tetradecapeptide and four target proteinases of the inhibitor. J Biol Chem 1992; 267:19047-50. [PMID: 1388162] [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] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
A tetradecapeptide corresponding to the P1 to P14 region of the reactive-bond loop of antithrombin (AT) binds to the inhibitor, presumably as a middle strand of the A beta-sheet, thereby converting AT from an inhibitor to a substrate of thrombin (Björk, I., Ylinenjärvi, K., Olson, S.T., and Bock, P. E. (1992) J. Biol. Chem. 267, 1976-1982). The kinetics of cleavage of the AT reactive bond in the AT-peptide complex by four target proteinases were quantified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and densitometry. The kcat/Km values for thrombin and factor IXa were indistinguishable from the second-order rate constants for AT inhibition of these enzymes, whereas the values for factor Xa and plasmin were 10-17-fold higher than the inhibition rate constants. Heparin with high affinity for AT accelerated the substrate reaction with thrombin to an extent consistent with the reduced heparin affinity of the AT-peptide complex. These data show that blocking by the peptide of the putative intramolecular association of the P1 to P14 region of the AT reactive-bond loop with the A beta-sheet leads to AT functioning as a substrate of its target enzymes with an efficiency that equals or exceeds the action of uncomplexed AT as an inhibitor and with the expected heparin activation. The results thus suggest that a substrate-like attack of the proteinase on the inhibitor reactive bond in an exposed loop initiates the inhibition reaction. This attack presumably induces the subsequent trapping of the enzyme by the insertion of the reactive-bond loop into the A beta-sheet.
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Affiliation(s)
- I Björk
- Department of Veterinary Medical Chemistry, Swedish University of Agricultural Sciences, Uppsala
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28
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Björk I, Nordling K, Larsson I, Olson S. Kinetic characterization of the substrate reaction between a complex of antithrombin with a synthetic reactive-bond loop tetradecapeptide and four target proteinases of the inhibitor. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(18)41737-1] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Abstract
A technique for the separation of neutrophils from macrophages-epithelial cells in samples of nonmastitic bovine milk with low cell counts has been developed. The procedure is based on centrifugation in a discontinuous metrizamide gradient and is rapid, taking less than 40 min. The recovery of the neutrophils is about 30% and their viability about 90%. The isolated neutrophils showed an appreciable unstimulated luminol- and lucigenin-dependent chemiluminescence, which was due to NADPH oxidase rather than to xanthine oxidase. The neutrophils had a higher rate of ingestion of C3-opsonized particles than macrophages-epithelial cells, whereas no significant differences in phagocytosis of IgG-opsonized yeast or unopsonized yeast were detected between the two cell populations. The macrophages-epithelial cells produced no luminol-dependent chemiluminescence and induced considerably lower activity in the lucigenin-dependent system than neutrophils, indicating that these cells contain no myeloperoxidase. Analyses of the activity of the neutrophils in response to C3-opsonized yeast particles showed that the luminol-dependent chemiluminescence of cells isolated from residual milk increased significantly over the lactation period. Moreover, a tendency to a higher phagocytosis and chemiluminescence of neutrophils isolated from residual milk than from stripping milk was indicated.
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Affiliation(s)
- C H Sandgren
- Department of Veterinary Medical Chemistry, Swedish University of Agricultural Sciences, Uppsala Biomedical Center
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30
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Sandgren CH, Nordling K, Björk I. A new technique, requiring small amounts of cells, for the parallel study of chemiluminescence and phagocytosis via different receptors in the same cell population. J Immunol Methods 1991; 141:63-72. [PMID: 1907628 DOI: 10.1016/0022-1759(91)90210-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [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: 12/29/2022]
Abstract
An assay permitting the parallel assessment of phagocytosis and chemiluminescence in the same cell population has been developed. The method is based on the phagocytosis of fluorescein isothiocyanate-conjugated yeast particles, either unopsonized or opsonized with complement factor C3 or IgG, by purified cells in suspension in a luminometer. Only a small number of cells (2 x 10(4)-1 x 10(5)) is required, and the reproducibility is high. Moreover, the technique permits phagocytosis to be related to oxygen-dependent killing activity in the same cell population. Since phagocytosis, degranulation and oxygen radical formation as a consequence of well-defined receptor recognition mechanisms can be characterized in very small cell populations, the method is suitable for monitoring the phagocytic function of cells from extravascular sites.
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Affiliation(s)
- C H Sandgren
- Department of Veterinary Medical Chemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden
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Fish WW, Danielsson A, Nordling K, Miller SH, Lam CF, Björk I. Denaturation behavior of antithrombin in guanidinium chloride. Irreversibility of unfolding caused by aggregation. Biochemistry 1985; 24:1510-7. [PMID: 3986191 DOI: 10.1021/bi00327a033] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The structural stability of the protease inhibitor antithrombin from bovine plasma was examined as a function of the concentration of guanidinium chloride (GdmCl). A biphasic unfolding curve at pH 7.4, with midpoints for the two phases at 0.8 and 2.8 M GdmCl, was measured by far-ultraviolet circular dichroism. Spectroscopic and hydrodynamic analyses suggest that the intermediate state which exists at 1.5 M GdmCl involves a partial unfolding of the antithrombin molecule that exposes regions of the polypeptide chain through which slow, intermolecular association subsequently takes place. The partially unfolded molecule can be reversed to its fully functional state only before the aggregation occurs. Upon return of the aggregated state to dilute buffer, the partially unfolded antithrombin remains aggregated and does not regain the spectroscopic properties, thrombin-inhibitory activity, or heparin affinity of the native inhibitor. This behavior indicates that the loss of the functional properties of the proteins is caused by the macromolecular association. Comparative experiments gave similar results for the human inhibitor. Analyses of bovine antithrombin in 6 M GdmCl indicated that the second transition reflects the total unfolding of the protein to a disulfide-cross-linked random coil. This transition is spectroscopically reversible; however, on further reversal to dilute buffer, the molecules apparently are trapped in the partially unfolded, aggregated, intermediate state. The results are consistent with the existence of two separate domains in antithrombin which unfold at different concentrations of GdmCl but do not support the contention that the thrombin-binding and heparin-binding regions of the protein are located in different domains [Villanueva, G. B., & Allen, N. (1983) J. Biol. Chem. 258, 14048-14053].
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Lindahl U, Thunberg L, Bäckström G, Riesenfeld J, Nordling K, Björk I. Extension and structural variability of the antithrombin-binding sequence in heparin. J Biol Chem 1984; 259:12368-76. [PMID: 6490618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Oligosaccharides with different affinities for antithrombin were isolated following partial deaminative cleavage of pig mucosal heparin with nitrous acid. The smallest high-affinity component obtained was previously identified as an octasaccharide with the predominant structure: (Formula: see text). The interaction of this octasaccharide, and of deca- and dodecasaccharides containing the same octasaccharide sequence, with antithrombin was studied by spectroscopic techniques. The near-ultraviolet difference spectra, circular dichroism spectra, and fluorescence enhancements induced by adding these oligosaccharides to antithrombin differed only slightly from the corresponding parameters measured in the presence of undegraded high-affinity heparin. Moreover, the binding constants obtained for the oligosaccharides and for high-affinity heparin were similar (1.0-2.9 X 10(7) M-1 at I = 0.3). In contrast, two hexasaccharides corresponding to units 1-6 and 3-8, respectively, of the above sequence showed about a 1000-fold lower affinity for antithrombin, and also induced considerably different spectral perturbations in antithrombin. Since the 1-6 hexasaccharide contains a reducing-terminal anhydromannose residue instead of the N-sulfated glucosamine unit 6 of the intact sequence, these results strongly support our previous conclusion that the N-sulfate group at position 6 is essential to the interaction with antithrombin. The low affinity of the hexasaccharide 3-8 provides further evidence that a pentasaccharide sequence 2-6 constitutes the actual antithrombin-binding region in the heparin molecule. Structural analysis of the various oligosaccharides revealed natural variants with an N-sulfate group substituted for the N-acetyl group at position 2. The preponderance of N-acetyl over N-sulfate groups at this position may be rationalized in terms of the mechanism of heparin biosynthesis, assuming that the D-gluco configuration of unit 3 is an essential feature of the antithrombin-binding region.
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Lindahl U, Thunberg L, Bäckström G, Riesenfeld J, Nordling K, Björk I. Extension and structural variability of the antithrombin-binding sequence in heparin. J Biol Chem 1984. [DOI: 10.1016/s0021-9258(18)90755-6] [Citation(s) in RCA: 248] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Björk I, Larm O, Lindahl U, Nordling K, Riquelme ME. Permanent activation of antithrombin by covalent attachment of heparin oligosaccharides. FEBS Lett 1982; 143:96-100. [PMID: 7117524 DOI: 10.1016/0014-5793(82)80281-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Björk I, Jackson CM, Jörnvall H, Lavine KK, Nordling K, Salsgiver WJ. The active site of antithrombin. Release of the same proteolytically cleaved form of the inhibitor from complexes with factor IXa, factor Xa, and thrombin. J Biol Chem 1982; 257:2406-11. [PMID: 6977539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Reactions between near equimolar amounts of antithrombin and Factors IXa or Xa resulted in the formation of a free proteolytically modified, two-chain form of the inhibitor, in addition to the inactive antithrombin-protease complexes. The modified inhibitor produced by either enzyme was electrophoretically identical with that formed in the reaction with thrombin. As in the latter reaction, the formation of the modified antithrombin by Factor Xa was increased in the presence of heparin, while only small amounts were produced by Factor IXa both in the absence and presence of the polysaccharide. NH2-terminal sequence analyses of the isolated modified inhibitor formed by Factor Xa showed that a single Arg-Ser bond in the COOH-terminal end of the inhibitor had been cleaved. This cleavage site is identical with that identified in free thrombin-modified antithrombin. The purified antithrombin-Factor IXa and antithrombin-Factor Xa complexes were dissociated by ammonia or hydroxylamine into free enzyme and a modified two-chain form of the inhibitor. Electrophoresis studies and NH2-terminal sequence analyses showed that the modified antithrombin obtained from either complex was identical with that produced in free form by the two enzymes and also with the modified inhibitor that is released from the antithrombin-thrombin complex. The fact that identical results were obtained for the reactions between antithrombin and three enzymes with different specificities strongly suggests that the observed Arg-Ser cleavage site is the active site of antithrombin.
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Björk I, Jackson CM, Jörnvall H, Lavine KK, Nordling K, Salsgiver WJ. The active site of antithrombin. Release of the same proteolytically cleaved form of the inhibitor from complexes with factor IXa, factor Xa, and thrombin. J Biol Chem 1982. [DOI: 10.1016/s0021-9258(18)34938-x] [Citation(s) in RCA: 90] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Wallgren P, Nordling K, Björk I. Immunological evidence for a proteolytic cleavage at the active site of antithrombin in the mechanism of inhibition of coagulation serine proteases. Eur J Biochem 1981; 116:493-6. [PMID: 6790279 DOI: 10.1111/j.1432-1033.1981.tb05363.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Previous studies have shown that a modified form of antithrombin, cleaved at a single Arg-Ser bond near the carboxy-terminal end of the chain, is formed during the reaction with thrombin concurrent with the formation of the inactive enzyme-inhibitor complex. A variety of evidence suggests that this cleavage site is the active site of antithrombin. In this work, antisera against intact antithrombin, the modified form of antithrombin and the antithrombin-thrombin complex were used in immunodiffusion analyses to probe the state of the inhibitor in its complexes with coagulation serine proteases. The results show that new antigenic determinants not present in intact antithrombin are created in modified antithrombin by the single peptide-bond cleavage. the same antigenic determinants are found also in complexes between antithrombin and thrombin or factor Xa. No evidence for the exposure of other new determinants in the complexes was obtained. The most likely conclusion from these results is that antithrombin exists in its complexes with the serine proteases as the modified, two-chain form of the inhibitor. This suggests that the mechanism of inhibition involves proteolytic cleavage of the active site of antithrombin by the protease.
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Nordenman B, Nordling K, Björk I. A differential effect of low-affinity heparin on the inhibition of thrombin and factor Xa by antithrombin. Thromb Res 1980; 17:595-600. [PMID: 7368180 DOI: 10.1016/0049-3848(80)90100-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Björk I, Nordling K. Evidence by chemical modification for the involvement of one or more tryptophanyl residues of bovine antithrombin in the binding of high-affinity heparin. Eur J Biochem 1979; 102:497-502. [PMID: 527591 DOI: 10.1111/j.1432-1033.1979.tb04265.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Tryptophanyl residues of bovine antithrombin were modified with N-bromosuccinimide at near-neutral pH. The reaction was found to be specific for tryptophan at low levels of modification, i.e. when only up to 1--1.3 mol tryptophan/mol protein were oxidized. Further modification led to extensive side reactions. Modification of an average of about one tryptophanyl residue per protein molecule did not affect antithrombin activity measured in the absence of heparin, but decreased the activity assayed in the presence of heparin to about half the value given by unmodified antithrombin. Addition of an excess of high-affinity heparin to a similarly modified antithrombin sample resulted in much smaller circular dichroism, ultraviolet absorption and fluorescence changes than those observed with the intact protein. Modification experiments in the presence of excess high-affinity heparin gave a definitely lower extent of modification than when heparin was excluded. These studies thus reinforce the conclusion from previous spectroscopic analyses that one or more tryptophanyl residues of antithrombin are involved in the binding of high-affinity heparin, presumably by being located at or close to the heparin binding site.
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