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Pires Ferreira D, Gruntman AM, Flotte TR. Gene therapy for alpha-1 antitrypsin deficiency: an update. Expert Opin Biol Ther 2023; 23:283-291. [PMID: 36825473 DOI: 10.1080/14712598.2023.2183771] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
INTRODUCTION Altering the human genetic code has been explored since the early 1990s as a definitive answer for the treatment of monogenic and acquired diseases which do not respond to conventional therapies. In Alpha-1 antitrypsin deficiency (AATD) the proper synthesis and secretion of alpha-1 antitrypsin (AAT) protein is impaired, leading to its toxic hepatic accumulation along with its pulmonary insufficiency, which is associated with parenchymal proteolytic destruction. Because AATD is caused by mutations in a single gene whose correction alone would normalize the mutant phenotype, it has become a popular target for both augmentation gene therapy and gene editing. Although gene therapy products are already a reality for the treatment of some pathologies, such as inherited retinal dystrophy and spinal muscular atrophy, AATD-related pulmonary and, especially, liver diseases still lack effective therapeutic options. AREAS COVERED Here, we review the course, challenges, and achievements of AATD gene therapy as well as update on new strategies being developed. EXPERT OPINION Reaching safe and clinically effective expression of the AAT is currently the greatest challenge for AATD gene therapy. The improvement and emergence of technologies that use gene introduction, silencing and correction hold promise for the treatment of AATD.
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Affiliation(s)
- Debora Pires Ferreira
- Department of Pediatrics, University of Massachusetts Chan Medical School, Worcester, MA, United States
| | - Alisha M Gruntman
- Department of Pediatrics, University of Massachusetts Chan Medical School, Worcester, MA, United States
| | - Terence R Flotte
- Department of Pediatrics, University of Massachusetts Chan Medical School, Worcester, MA, United States
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2
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Recombinant Alpha-1 Antitrypsin as Dry Powder for Pulmonary Administration: A Formulative Proof of Concept. Pharmaceutics 2022; 14:pharmaceutics14122754. [PMID: 36559248 PMCID: PMC9784676 DOI: 10.3390/pharmaceutics14122754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 12/05/2022] [Accepted: 12/06/2022] [Indexed: 12/13/2022] Open
Abstract
Alpha-1 antitrypsin (AAT) deficiency is a genetic disorder associated with pulmonary emphysema and bronchiectasis. Its management currently consists of weekly infusions of plasma-purified human AAT, which poses several issues regarding plasma supplies, possible pathogen transmission, purification costs, and parenteral administration. Here, we investigated an alternative administration strategy for augmentation therapy by combining recombinant expression of AAT in bacteria and the production of a respirable powder by spray drying. The same formulation approach was then applied to plasma-derived AAT for comparison. Purified, active, and endotoxin-free recombinant AAT was produced at high yields and formulated using L-leucine and mannitol as excipients after identifying compromise conditions for protein activity and good aerodynamic performances. An oxygen-free atmosphere, both during formulation and powder storage, slowed down methionine-specific oxidation and AAT inactivation. This work is the first peer-reviewed report of AAT formulated as a dry powder, which could represent an alternative to current treatments.
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Rahaghi FF. Alpha-1 antitrypsin deficiency research and emerging treatment strategies: what's down the road? Ther Adv Chronic Dis 2021; 12_suppl:20406223211014025. [PMID: 34408832 PMCID: PMC8367209 DOI: 10.1177/20406223211014025] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 04/08/2021] [Indexed: 01/29/2023] Open
Abstract
Intravenous infusion of alpha-1 antitrypsin (AAT) was approved by the United States Food and Drug Administration (FDA) to treat emphysema associated with AAT deficiency (AATD) in 1987 and there are now several FDA-approved therapy products on the market, all of which are derived from pooled human plasma. Intravenous AAT therapy has proven clinical efficacy in slowing the decline of lung function associated with AATD progression; however, it is only recommended for individuals with the most severe forms of AATD as there is a lack of evidence that this treatment is effective in treating wild-type heterozygotes (e.g., PI*MS and PI*MZ genotypes), for which the prevalence may be much higher than previously thought. There are large numbers of individuals that are currently left untreated despite displaying symptoms of AATD. Furthermore, not all countries offer AAT augmentation therapy due to its expense and inconvenience for patients. More cost-effective treatments are now being sought that show efficacy for less severe forms of AATD and many new therapeutic technologies are being investigated, such as gene repair and other interference strategies, as well as the use of chemical chaperones. New sources of AAT are also being investigated to ensure there are enough supplies to meet future demand, and new methods of assessing response to treatment are being evaluated. There is currently extensive research into AATD and its treatment, and this chapter aims to highlight important emerging treatment strategies that aim to improve the lives of patients with AATD.
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Affiliation(s)
- Franck F Rahaghi
- Advanced Lung Disease Clinic, Cleveland Clinic Florida, 2950 Cleveland Clinic Boulevard, Weston, FL 33331, USA
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4
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Bianchera A, Alomari E, Bruno S. Augmentation therapy with alpha 1-antitrypsin: present and future of production, formulation, and delivery. Curr Med Chem 2021; 29:385-410. [PMID: 34036902 DOI: 10.2174/0929867328666210525161942] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 03/24/2021] [Accepted: 04/12/2021] [Indexed: 11/22/2022]
Abstract
Alpha 1-antitrypsin is one of the first protein therapeutics introduced on the market - more than 30 years ago - and, to date, it is indicated only for the treatment of the severe forms of a genetic condition known as alpha-1 antitrypsin deficiency. The only approved preparations are derived from plasma, posing potential problems associated with its limited supply and high processing costs. Moreover, augmentation therapy with alpha 1-antitrypsin is still limited to intravenous infusions, a cumbersome regimen for patients. Here, we review the recent literature on its possible future developments, focusing on i) the recombinant alternatives to the plasma-derived protein, ii) novel formulations, and iii) novel administration routes. Regulatory issues and the still unclear noncanonical functions of alpha 1-antitrypsin - possibly associated with the glycosylation pattern found only in the plasma-derived protein - have hindered the introduction of new products. However, potentially new therapeutic indications other than the treatment of alpha-1 antitrypsin deficiency might open the way to new sources and new formulations.
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Affiliation(s)
- Annalisa Bianchera
- Dipartimento di Scienze degli Alimenti e del Farmaco, University of Parma, Parma, Italy
| | - Esraa Alomari
- Dipartimento di Scienze degli Alimenti e del Farmaco, University of Parma, Parma, Italy
| | - Stefano Bruno
- Dipartimento di Scienze degli Alimenti e del Farmaco, University of Parma, Parma, Italy
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5
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Scott BM, Sheffield WP. Engineering the serpin α 1 -antitrypsin: A diversity of goals and techniques. Protein Sci 2019; 29:856-871. [PMID: 31774589 DOI: 10.1002/pro.3794] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 11/19/2019] [Accepted: 11/19/2019] [Indexed: 12/19/2022]
Abstract
α1 -Antitrypsin (α1 -AT) serves as an archetypal example for the serine proteinase inhibitor (serpin) protein family and has been used as a scaffold for protein engineering for >35 years. Techniques used to engineer α1 -AT include targeted mutagenesis, protein fusions, phage display, glycoengineering, and consensus protein design. The goals of engineering have also been diverse, ranging from understanding serpin structure-function relationships, to the design of more potent or more specific proteinase inhibitors with potential therapeutic relevance. Here we summarize the history of these protein engineering efforts, describing the techniques applied to engineer α1 -AT, specific mutants of interest, and providing an appended catalog of the >200 α1 -AT mutants published to date.
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Affiliation(s)
- Benjamin M Scott
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland.,Biosystems and Biomaterials Division, National Institute of Standards and Technology, Gaithersburg, Maryland
| | - William P Sheffield
- Canadian Blood Services, Centre for Innovation, Hamilton, Ontario, Canada.,Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
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Pye A, Turner AM. Experimental and investigational drugs for the treatment of alpha-1 antitrypsin deficiency. Expert Opin Investig Drugs 2019; 28:891-902. [PMID: 31550938 DOI: 10.1080/13543784.2019.1672656] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Introduction: Alpha-1 antitrypsin deficiency (AATD) is most often associated with chronic lung disease, early onset emphysema, and liver disease. The standard of care in lung disease due to AATD is alpha-1 antitrypsin augmentation but there are several new and emerging treatment options under investigation for both lung and liver manifestations. Areas covered: We review therapeutic approaches to lung and liver disease in alpha-1 antitrypsin deficiency (AATD) and the agents in clinical development according to their mode of action. The focus is on products in clinical trials, but data from pre-clinical studies are described where relevant, particularly where progression to trials appears likely. Expert opinion: Clinical trials directed at lung and liver disease separately are now taking place. Multimodality treatment may be the future, but this could be limited by treatment costs. The next 5-10 years may reveal new guidance on when to use therapeutics for slowing disease progression with personalized treatment regimes coming to the forefront.
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Affiliation(s)
- Anita Pye
- Institute of Applied Health Research, University of Birmingham , Birmingham , UK
| | - Alice M Turner
- Institute of Applied Health Research, University of Birmingham , Birmingham , UK
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7
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Downstream Processing for Biopharmaceuticals Recovery. ENVIRONMENTAL CHEMISTRY FOR A SUSTAINABLE WORLD 2019. [DOI: 10.1007/978-3-030-01881-8_6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Michel T, Kankura A, Salinas Medina ML, Kurz J, Behring A, Avci-Adali M, Nolte A, Schlensak C, Wendel HP, Krajewski S. In Vitro Evaluation of a Novel mRNA-Based Therapeutic Strategy for the Treatment of Patients Suffering from Alpha-1-Antitrypsin Deficiency. Nucleic Acid Ther 2015; 25:235-44. [PMID: 26125662 DOI: 10.1089/nat.2015.0537] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
In single-gene disorders, like alpha-1-antitrypsin deficiency (AATD), a gene mutation causes missing or dysfunctional protein synthesis. This, in turn, can lead to serious complications for the patient affected. Furthermore, single-gene disorders are associated with severe early-onset conditions and necessitate expensive lifelong care. Until nowadays, therapeutic treatment options are still limited, cost-intensive, or lack effectiveness. For these reasons, we aim to develop a novel mRNA-based therapeutic strategy for the treatment of single-gene disorders, such as AATD, which is based on the induction of de novo synthesis of the functional proteins. Therefore, an alpha-1-antitrypsin (AAT) encoding mRNA was generated by in vitro transcription. After in vitro delivery of the mRNA to different cells, protein expression and functionality, as well as adverse effects and mRNA serum stability, were analyzed. Our results show that the AAT mRNA-transfected cells express the AAT protein in high amounts within the first 24 h. Moreover, the expressed AAT protein is highly functional, since the activity of elastase is significantly inhibited. Our data also show that mRNA concentrations up to 1 μg per 150,000 cells have no adverse effects on cell viability and immune activation. Furthermore, the encapsulated AAT encoding mRNA is stable and functional in human serum for up to 30 min. Overall, the proposed project provides an innovative, highly promising, and safe therapeutic approach and, thus, promises a novel progress in the treatment of single-gene disorders, whereby affected patients could greatly benefit.
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Affiliation(s)
- Tatjana Michel
- Clinical Research Laboratory, Department of Thoracic and Cardiovascular Surgery, University Hospital Tuebingen, Tuebingen University , Tuebingen, Germany
| | - Anna Kankura
- Clinical Research Laboratory, Department of Thoracic and Cardiovascular Surgery, University Hospital Tuebingen, Tuebingen University , Tuebingen, Germany
| | - Martha L Salinas Medina
- Clinical Research Laboratory, Department of Thoracic and Cardiovascular Surgery, University Hospital Tuebingen, Tuebingen University , Tuebingen, Germany
| | - Julia Kurz
- Clinical Research Laboratory, Department of Thoracic and Cardiovascular Surgery, University Hospital Tuebingen, Tuebingen University , Tuebingen, Germany
| | - Andreas Behring
- Clinical Research Laboratory, Department of Thoracic and Cardiovascular Surgery, University Hospital Tuebingen, Tuebingen University , Tuebingen, Germany
| | - Meltem Avci-Adali
- Clinical Research Laboratory, Department of Thoracic and Cardiovascular Surgery, University Hospital Tuebingen, Tuebingen University , Tuebingen, Germany
| | - Andrea Nolte
- Clinical Research Laboratory, Department of Thoracic and Cardiovascular Surgery, University Hospital Tuebingen, Tuebingen University , Tuebingen, Germany
| | - Christian Schlensak
- Clinical Research Laboratory, Department of Thoracic and Cardiovascular Surgery, University Hospital Tuebingen, Tuebingen University , Tuebingen, Germany
| | - Hans Peter Wendel
- Clinical Research Laboratory, Department of Thoracic and Cardiovascular Surgery, University Hospital Tuebingen, Tuebingen University , Tuebingen, Germany
| | - Stefanie Krajewski
- Clinical Research Laboratory, Department of Thoracic and Cardiovascular Surgery, University Hospital Tuebingen, Tuebingen University , Tuebingen, Germany
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9
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Turner AM. Alpha-1 antitrypsin deficiency: new developments in augmentation and other therapies. BioDrugs 2014; 27:547-58. [PMID: 23771682 DOI: 10.1007/s40259-013-0042-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Alpha 1 antitrypsin deficiency (AATD) is a rare cause of chronic obstructive pulmonary disease. The lung disease is thought to be caused primarily by a lack of effective protection against the harmful effects of neutrophil elastase due to the low AAT levels in the lung. Patients may also develop liver disease due to polymerisation of AAT within hepatocytes. Consequently there has been much research over the years into AAT augmentation therapy in patients with lung disease, initially intravenously, and more recently in inhaled forms. This review article will discuss the role of augmentation therapy in AATD and the current status of recombinant AAT. The potential for other therapeutic strategies, such as blocking polymer formation, enhancing autophagy, gene therapy and stem cell-based treatment, will also be discussed more briefly.
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Affiliation(s)
- Alice M Turner
- QEHB Research Labs, University of Birmingham, Mindelsohn Way, Birmingham, B15 2WB, UK,
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10
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Functional analysis of novel alpha-1 antitrypsin variants G320R and V321F. Mol Biol Rep 2014; 41:6133-41. [PMID: 24969485 DOI: 10.1007/s11033-014-3492-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Accepted: 06/17/2014] [Indexed: 12/12/2022]
Abstract
Alpha-1 antitrypsin (AAT) gene is highly polymorphic, with a large number of rare variants whose phenotypic consequences often remain inconclusive. Studies addressing functional characteristics of AAT variants are of significant biomedical importance since deficiency and dysfunctionality of AAT are associated with liver and lung diseases. We report the results of the functional analysis of two naturally occurring AAT variants, G320R and V321F, previously identified in patients with lung disease. Neither of variants has been fully functionally characterized. In order to perform their functional analysis both variants were expressed in prokaryotic and eukaryotic systems and their intracellular localization, activity, stability, and polymerization were determined. The results of this study demonstrated that variants G320R and V321F have neither impaired activity against porcine pancreatic elastase nor propensity to form polymers. However, both variants had altered electrophoretic mobility and reduced thermostability when compared to M variant of the protein, indicating a slightly impaired secondary or tertiary structure.
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11
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Midon M, Gimadutdinow O, Meiss G, Friedhoff P, Pingoud A. Chemical Rescue of Active Site Mutants of S. pneumoniae Surface Endonuclease EndA and Other Nucleases of the HNH Family by Imidazole. Chembiochem 2012; 13:713-21. [DOI: 10.1002/cbic.201100775] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Indexed: 11/08/2022]
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12
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Rakabe M, Van Wyngaardt W, Fehrsen J. Chicken single-chain antibody fragments directed against recombinant VP7 of bluetongue virus. FOOD AGR IMMUNOL 2011. [DOI: 10.1080/09540105.2011.575122] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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13
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Chill L, Trinh L, Azadi P, Ishihara M, Sonon R, Karnaukhova E, Ophir Y, Golding B, Shiloach J. Production, purification, and characterization of human alpha1 proteinase inhibitor from Aspergillus niger. Biotechnol Bioeng 2009; 102:828-44. [PMID: 18828177 DOI: 10.1002/bit.22099] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Human alpha one proteinase inhibitor (alpha1-PI) was cloned and expressed in Aspergillus niger, filamentious fungus that can grow in defined media and can perform glycosylation. Submerged culture conditions were established using starch as carbon source, 30% dissolved oxygen concentration, pH 7.0 and 28 degrees C. Eight milligrams per liter of active alpha1-PI were secreted to the growth media in about 40 h. Controlling the protein proteolysis was found to be an important factor in the production. The effects of various carbon sources, pH and temperature on the production and stability of the protein were tested and the product was purified and characterized. Two molecular weights variants of the recombinant alpha1-PI were produced by the fungus; the difference is attributed to the glycosylated part of the molecule. The two glycoproteins were treated with PNGAse F and the released glycans were analyzed by HPAEC, MALDI/TOF-MS, NSI-MS(n), and GC-MS. The MALDI and NSI- full MS spectra of permethylated N-glycans revealed that the N-glycans of both variants contain a series of high-mannose type glycans with 5-20 hexose units. Monosaccharide analysis showed that these were composed of N-acetylglucos-amine, mannose, and galactose. Linkage analysis revealed that the galactosyl component was in the furanoic conformation, which was attaching in a terminal non-reducing position. The Galactofuranose-containing high-mannnose type N-glycans are typical structures, which recently have been found as part of several glycoproteins produced by Aspergillus niger.
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Affiliation(s)
- Liat Chill
- Biotechnology Core Laboratory, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Building 14A Room 170, 9000 Rockville Pike, Bethesda, Maryland 20892, USA
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14
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Nadai M, Bally J, Vitel M, Job C, Tissot G, Botterman J, Dubald M. High-level expression of active human alpha1-antitrypsin in transgenic tobacco chloroplasts. Transgenic Res 2009; 18:173-83. [PMID: 18686007 DOI: 10.1007/s11248-008-9209-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2008] [Accepted: 07/04/2008] [Indexed: 11/26/2022]
Abstract
We have produced human alpha1-antitrypsin (A1AT), a major therapeutic protein, in genetically engineered tobacco plastids. Four different expression vectors have been evaluated which encode A1AT under the control of various 5' and 3' plastid expression elements. The use of heterologous promoter and terminator sequences derived from the corn and soybean plastid genomes leads to simpler and predictable recombinant genome patterns, avoiding unwanted recombination products between introduced and resident tobacco sequences. High level expression of unglycosylated A1AT, representing up to 2% of total soluble proteins, has been measured in leaves of transgenic tobacco lines. Some heterogeneity in the recombinant A1AT is detected after 2D protein separation, but the chloroplast-made protease inhibitors are fully active and bind to porcine pancreatic elastase.
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Affiliation(s)
- M Nadai
- Bayer BioScience, 14-20 Rue Pierre Baizet, BP 9163, 69263, Lyon cedex 09, France
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15
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Abstract
Alpha1-antitrypsin deficiency is a genetic disorder which contributes to the development of chronic obstructive pulmonary disease, bronchiectasis, liver cirrhosis and panniculitis. The discovery of alpha1-antitrypsin and its function as an antiprotease led to the protease-antiprotease hypothesis, which goes some way to explaining the pathogenesis of emphysema. This article will review the clinical features of alpha1-antitrypsin deficiency, the genetic mutations known to cause it, and how they do so at a molecular level. Specific treatments for the disorder based on this knowledge will be reviewed, including alpha1-antitrypsin replacement, gene therapy and possible future therapies, such as those based on stem cells.
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Affiliation(s)
- Alice M Wood
- Department of Medical Sciences, University of Birmingham, Birmingham, UK
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16
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Gupta VK, Appu Rao AG, Gowda LR. Purification and biochemical characterization of ovine alpha-1-proteinase inhibitor: mechanistic adaptations and role of Phe350 and Met356. Protein Expr Purif 2007; 57:290-302. [PMID: 17997326 DOI: 10.1016/j.pep.2007.09.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2007] [Revised: 09/06/2007] [Accepted: 09/22/2007] [Indexed: 11/17/2022]
Abstract
The glycoprotein alpha-1-proteinase inhibitor (alpha-1-PI) is a member of the serpin super family that causes rapid and irreversible inhibition of redundant serine protease activity. A homogenous preparation of ovine alpha-1-PI, a 60 kDa protein was obtained by serially subjecting ovine serum to 40-70% (NH(4))(2)SO(4) precipitation, Blue Sepharose, size-exclusion, and concanavalin-A chromatography. Extensive insights into the trypsin, chymotrypsin, and elastase interaction with ovine alpha-1-PI, point towards the involvement of Phe(350) besides the largely conserved Met(356) in serine protease recognition and consequent inhibition. The N-terminal of C-terminal peptides cleaved on interaction with elastase, trypsin, and chymotrypsin prove the presence of diffused sub-sites in the vicinity of Met(356) and the strategically positioned Pro anchored peptide stretch. Further, human alpha-1-PI is more thermolabile compared to ovine alpha-1-PI, higher thermolability is mainly attributed to poorer glycosylation. The enzymatic deglycosylation of human and ovine alpha-1-PI results in diminished thermostability of the inhibitors, with sharp decrease in thermal transition temperatures but retaining their inhibitory potency. Homology modeling of the deduced amino acid sequence of ovine alpha-1-PI using the human alpha-1-PI template has been used to explain the observed inhibitor-protease interactions.
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Affiliation(s)
- Vivek K Gupta
- Department of Protein Chemistry and Technology, Central Food Technological Research Institute, Mysore, Karnataka 570020, India
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17
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Chill L, Trinh LB, Karnaukhova E, Ophir Y, Golding B, Shiloach J. Production of human α1 proteinase inhibitor from Aspergillus niger. Microb Cell Fact 2006. [DOI: 10.1186/1475-2859-5-s1-p62] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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18
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Karnaukhova E, Ophir Y, Golding B. Recombinant human alpha-1 proteinase inhibitor: towards therapeutic use. Amino Acids 2006; 30:317-32. [PMID: 16773239 DOI: 10.1007/s00726-005-0324-4] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2005] [Accepted: 01/31/2006] [Indexed: 01/07/2023]
Abstract
Human alpha-1-proteinase inhibitor is a well-characterized protease inhibitor with a wide spectrum of anti-protease activity. Its major physiological role is inhibition of neutrophil elastase in the lungs, and its deficiency is associated with progressive ultimately fatal emphysema. Currently in the US, only plasma-derived human alpha-1-proteinase inhibitor is available for augmentation therapy, which appears to be insufficient to meet the anticipated clinical demand. Moreover, despite effective viral clearance steps in the manufacturing process, the potential risk of contamination with new and unknown pathogens still exists. In response, multiple efforts to develop recombinant versions of human alpha-1-proteinase inhibitor, as an alternative to the plasma-derived protein, have been reported. Over the last two decades, various systems have been used to express the human gene for alpha-1-proteinase inhibitor. This paper reviews the recombinant versions of human alpha-1-proteinase inhibitor produced in various hosts, considers current major safety and efficacy issues regarding recombinant glycoproteins as potential therapeutics, and the factors that are impeding progress in this area(1).
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Affiliation(s)
- E Karnaukhova
- Division of Hematology, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, Maryland 20892, USA.
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19
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Dufour EK, Denault JB, Bissonnette L, Hopkins PC, Lavigne P, Leduc R. The contribution of arginine residues within the P6-P1 region of alpha 1-antitrypsin to its reaction with furin. J Biol Chem 2001; 276:38971-9. [PMID: 11479287 DOI: 10.1074/jbc.m102959200] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A series of mutants incorporating furin recognition sequences within the P6-P1 region of the reactive site loop of alpha(1)-antitrypsin were constructed. Variants containing different combinations of basic residues in the P1, P2, P4, and P6 positions replacing the wild type (P6)LEAIPM(P1) sequence were evaluated for their capacity to establish SDS-resistant complexes with furin, to affect association rate constants (k(ass) and k'(ass)), or to inhibit furin-dependent proteolysis of a model precursor in vivo. Each variant abolished processing of pro-von Willebrand factor in transfected hEK293 cells. The k(ass) of all variants were found to be similar (1.1-1.7 x 10(6) m(-1) s(-1)) except for one mutant, RERIRR, which had a k(ass) of 3.3 x 10(5) m(-1) s(-1). However, the stoichiometry of inhibition varied with values ranging from 2.9 to >24, indicating rapid formation of the acyl-enzyme intermediate (high k'(ass)). Moreover, those variants having high stoichiometry of inhibition values were accompanied by the rapid formation of cleaved forms of the inhibitors. The data suggest that the rate of conversion of the acyl-enzyme (EI') into the highly stable complex (EI*) was affected by replacement of specific residues within the reactive site loop. Taken together, the results reveal how furin recognition sequences within the context of the biochemical properties of serpins will play a role in the capacity of the protein to follow either the inhibitory or the substrate pathway.
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Affiliation(s)
- E K Dufour
- Gladstone Institute of Cardiovascular Disease, San Francisco, California 94141, USA
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20
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Genschel J, Curth U, Urbanke C. Interaction of E. coli single-stranded DNA binding protein (SSB) with exonuclease I. The carboxy-terminus of SSB is the recognition site for the nuclease. Biol Chem 2000; 381:183-92. [PMID: 10782989 DOI: 10.1515/bc.2000.025] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The 3'-5' single-stranded DNA(ssDNA) degrading exonuclease I of E. coli directly interacts with the E. coli ssDNA binding protein (EcoSSB). Analytical ultracentrifugation shows that all 4 carboxy-termini of an EcoSSB tetramer bind exonuclease I. Binding is weakened by increasing salt concentrations, indicating the involvement of the negatively charged amino acids of the carboxy-terminus of SSB. Mutant SSB proteins EcoSSBP176S (ssb-113) and EcoSSBF177C do not bindtoexonuclease I while EcoSSBG15D (ssb-3) does bind. In a co-precipitation assay we show that the absence of the lastten amino acids (PMDFDDDIPF) completely abolishes binding of EcoSSB to exonuclease I. The interaction does not depend on the presence of the correct amino-terminal DNA binding domain or the amino acid sequences between the DNA binding domain and the last ten amino acids. A synthetic peptide (WMDFDDDIPF), corresponding to the last nine amino acids of EcoSSB, specifically inhibits the interaction. Both EcoSSBP176S and EcoSSBF177C SSBs bind DNA similar to wild-type EcoSSB, indicating that the phenotype of ssb-113 is not an indication of altered DNA binding. The repair deficiency of either ssb-3 or ssb-113 strain can be complemented by overexpression of the respective other mutant.
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Affiliation(s)
- J Genschel
- Medizinische Hochschule Hannover, Biophysikalische Chemie, Hannover, Germany
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21
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Mackey ZB, Niedergang C, Murcia JM, Leppard J, Au K, Chen J, de Murcia G, Tomkinson AE. DNA ligase III is recruited to DNA strand breaks by a zinc finger motif homologous to that of poly(ADP-ribose) polymerase. Identification of two functionally distinct DNA binding regions within DNA ligase III. J Biol Chem 1999; 274:21679-87. [PMID: 10419478 DOI: 10.1074/jbc.274.31.21679] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mammalian DNA ligases are composed of a conserved catalytic domain flanked by unrelated sequences. At the C-terminal end of the catalytic domain, there is a 16-amino acid sequence, known as the conserved peptide, whose role in the ligation reaction is unknown. Here we show that conserved positively charged residues at the C-terminal end of this motif are required for enzyme-AMP formation. These residues probably interact with the triphosphate tail of ATP, positioning it for nucleophilic attack by the active site lysine. Amino acid residues within the sequence RFPR, which is invariant in the conserved peptide of mammalian DNA ligases, play critical roles in the subsequent nucleotidyl transfer reaction that produces the DNA-adenylate intermediate. DNA binding by the N-terminal zinc finger of DNA ligase III, which is homologous with the two zinc fingers of poly(ADP-ribose) polymerase, is not required for DNA ligase activity in vitro or in vivo. However, this zinc finger enables DNA ligase III to interact with and ligate nicked DNA at physiological salt concentrations. We suggest that in vivo the DNA ligase III zinc finger may displace poly(ADP-ribose) polymerase from DNA strand breaks, allowing repair to occur.
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Affiliation(s)
- Z B Mackey
- Department of Molecular Medicine, Institute of Biotechnology, The University of Texas Health Science Center at San Antonio, San Antonio, Texas 78245, USA
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22
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Ador L, Camasses A, Erbs P, Cavarelli J, Moras D, Gangloff J, Eriani G. Active site mapping of yeast aspartyl-tRNA synthetase by in vivo selection of enzyme mutations lethal for cell growth. J Mol Biol 1999; 288:231-42. [PMID: 10329139 DOI: 10.1006/jmbi.1999.2679] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The active site of yeast aspartyl-tRNA synthetase has been characterised by structural and functional approaches. However, residues or structural elements that indirectly contribute to the active site organisation have still to be described. They have not been assessed by simple analysis of structural data or site-directed mutagenesis analysis, since rational targetting has proven difficult. Here, we attempt to locate these functional features by using a genetic selection method to screen a randomly mutated yeast AspRS library for mutations lethal for cell growth. This approach is an efficient method to map the active site residues, since of the 23 different mutations isolated, 13 are in direct contact with the substrates. Most of the mutations are located in a 15 A radius sphere around the ATP molecule, where they affect the very conserved residues of the class-defining motifs. The results also showed the importance of the dimer interface for the enzyme activity: a single mutation of the invariant proline residue of motif 1 led to a structural defect inactivating the enzyme. From in vivo complementation studies it appeared that the enzyme activity can be recovered by reconstitution of an intact interface through the formation of heterodimers. We also show that a single mutation affecting an interaction with G34 of the tRNA can inactivate the enzyme by inducing a relaxation of the tRNA recognition specificity. Finally, several mutants whose functional importance could not be assessed from the structural data were selected, demonstrating the importance of this type of approach in the context of a structure-function relationship study.
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Affiliation(s)
- L Ador
- UPR 9002 SMBMR, Institut de Biologie Moléculaire et Cellulaire, CNRS, 15, rue René Descartes, Strasbourg, 67084, France
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23
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Ruf A, Rolli V, de Murcia G, Schulz GE. The mechanism of the elongation and branching reaction of poly(ADP-ribose) polymerase as derived from crystal structures and mutagenesis. J Mol Biol 1998; 278:57-65. [PMID: 9571033 DOI: 10.1006/jmbi.1998.1673] [Citation(s) in RCA: 124] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The binding site for the acceptor substrate poly(ADP-ribose) in the elongation reaction of the ADP-ribosyl transferase poly(ADP-ribose) polymerase (PARP) was detected by cocrystallizing the enzyme with an NAD+ analogue. The site was confirmed by mutagenesis studies. In conjunction with the binding site of the donor NAD+, the bound acceptor reveals the geometry of the elongation reaction. It shows in particular that the strictly conserved glutamate residue of all ADP-ribosylating enzymes (Glu988 of PARP) facilitates the reaction by polarizing both, donor and acceptor. Moreover, the binding properties of the acceptor site suggest a mechanism for the branching reaction, that also explains the dual specificity of this transferase for elongation and branching, which is unique among polymer-forming enzymes.
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Affiliation(s)
- A Ruf
- Institut für Organische Chemie und Biochemie, Albertstr. 21, Freiburg im Breisgau, D-79104, Germany
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24
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Chen SX, Hammond DJ, Klos AM, Wood WD, Wydick JE, Lebing WR. Chromatographic purification of human alpha 1 proteinase inhibitor from dissolved Cohn fraction IV-1 paste. J Chromatogr A 1998; 800:207-18. [PMID: 9561763 DOI: 10.1016/s0021-9673(97)01119-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
A novel chromatographic process for purification of alpha 1 proteinase inhibitor (alpha 1-PI) from Cohn fraction IV-1 paste is described. This process has been successfully scaled up to 50-1 columns. It involves DEAE chromatography, sulfopropyl (S) cation chromatography, tri-n-butyl phosphate (TNBP)-cholate treatment, a second S cation chromatography, freeze-drying and dry-heat. The process has been optimized for purity, yield, lipid removal, chemical usage and water consumption. Filtration after TNBP-cholate treatment plays a key role in ensuring a low lipid content in the final product. Pre-equilibration with high salt buffer is necessary to reduce the water consumption significantly during the ion-exchange chromatography equilibration step. The final product is approximately 95% pure by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, with a 64% to 70% yield from IV-1 paste.
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Affiliation(s)
- S X Chen
- Bayer Corporation, Raleigh, NC 27606, USA
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25
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Kang HA, Sohn JH, Choi ES, Chung BH, Yu MH, Rhee SK. Glycosylation of human alpha 1-antitrypsin in Saccharomyces cerevisiae and methylotrophic yeasts. Yeast 1998; 14:371-81. [PMID: 9559545 DOI: 10.1002/(sici)1097-0061(19980315)14:4<371::aid-yea231>3.0.co;2-1] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Human alpha 1-antitrypsin (alpha 1-AT) is a major serine protease inhibitor in plasma, secreted as a glycoprotein with a complex type of carbohydrate at three asparagine residues. To study glycosylation of heterologous proteins in yeast, we investigated the glycosylation pattern of the human alpha 1-AT secreted in the baker's yeast Saccharomyces cerevisiae and in the methylotrophic yeasts, Hansenula polymorpha and Pichia pastoris. The partial digestion of the recombinant alpha 1-AT with endoglycosidase H and the expression in the mnn9 deletion mutant of S. cerevisiae showed that the recombinant alpha 1-AT secreted in S. cerevisiae was heterogeneous, consisting of molecules containing core carbohydrates on either two or all three asparagine residues. Besides the core carbohydrates, variable numbers of mannose outer chains were also added to some of the secreted alpha 1-AT. The human alpha 1-AT secreted in both methylotrophic yeasts was also heterogeneous and hypermannosylated as observed in S. cerevisiae, although the overall length of mannose outer chains of alpha 1-AT in the methylotrophic yeasts appeared to be relatively shorter than those of alpha 1-AT in S. cerevisiae. The alpha 1-AT secreted from both methylotrophic yeasts retained its biological activity as an elastase inhibitor comparable to that of alpha 1-AT from S. cerevisiae, suggesting that the different glycosylation profile does not affect the in vitro activity of the protein.
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Affiliation(s)
- H A Kang
- Korea Research Institute of Bioscience and Biotechnology (KRIBB), Taejon, Korea
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26
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Viana da Costa A, Gaubert S, Fontaine J, Lafitte S, Seixas A, De Lourdes Sampaio Silva M, Capron A, Grzych JM. Murine Schistosoma bovis infection: analysis of parasitic and immune parameters. Parasite Immunol 1998; 20:143-53. [PMID: 9568617 DOI: 10.1046/j.1365-3024.1998.00136.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Humoral and cellular responses to Schistosoma bovis antigens have been evaluated over a period of 11 weeks in mice exposed to S. bovis cercariae and data analysed in the context of the parasitic parameters (worm and egg loads) recorded at days 30, 60 and 80 of the ongoing infection. Results revealed a decrease of worm burden, particularly marked for female worms, between day 60 and day 80 of infection suggesting a higher susceptibility of female schistosomes to attrition mechanisms. The B-cell response, studied by measuring the production of different isotypes, was directed against different stage specific antigens, with a predominance of IgG1 antibodies associated with a significant increase of IgA and IgE antibodies after egg deposition. The T-cell response, assessed after in vitro stimulation of splenocytes, showed a predominant production of Th-2 cytokines (IL-4, IL-5 and IL-10) occurring after egg laying. Interestingly in contrast to S. mansoni infection the Th-2 polarization did not seem to be exclusively triggered by egg-associated antigens since significant amounts of IL-10 were produced after stimulation with adult worm antigen preparation (SWAP) before the beginning of egg deposition.
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Affiliation(s)
- A Viana da Costa
- Centre d'immunologie et de Biologie Parasitaire, Unité INSERM U-167, Institut Pasteur de Lille, France
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27
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Kim H, Jacobson MK, Rolli V, Ménissier-de Murcia J, Reinbolt J, Simonin F, Ruf A, Schulz G, de Murcia G. Photoaffinity labelling of human poly(ADP-ribose) polymerase catalytic domain. Biochem J 1997; 322 ( Pt 2):469-75. [PMID: 9065765 PMCID: PMC1218214 DOI: 10.1042/bj3220469] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Photoaffinity labelling of the human poly(ADP-ribose) polymerase (PARP) catalytic domain (40 kDa) with the NAD+ photoaffinity analogue 2-azido-[alpha-32P]NAD+ has been used to identify NAD+-binding residues. In the presence of UV, photo-insertion of the analogue was observed with a stoichiometry of 0.73 mol of 2-azido-[alpha-32P]NAD+ per mol of catalytic domain. Competition experiments indicated that 3-aminobenzamide strongly protected the insertion site. Residues binding the adenine ring of NAD+ were identified by trypsin digestion and boronate affinity chromatography in combination with reverse-phase HPLC. Two major NAD+-binding residues, Trp1014 of peptide Thr1011-Trp1014 and Lys893 of peptide Ile979-Lys893, were identified. The site-directed mutagenesis of these two residues revealed that Lys893, but not Trp1014, is critical for activity. The close positioning of Lys893 near the adenine ring of NAD+ has been confirmed by the recently solved crystallographic structure of the chicken PARP catalytic domain [Ruf, Menissier-de Murcia, de Murcia and Schulz (1996) Proc. Natl. Acad. Sci. U.S.A. 93, 7481-7485].
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Affiliation(s)
- H Kim
- Division of Medicinal Chemistry and Pharmaceutics, College of Pharmacy, University of Kentucky, Lexington 40536-0082, U.S.A
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28
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Trucco C, Flatter E, Fribourg S, de Murcia G, Ménissier-de Murcia J. Mutations in the amino-terminal domain of the human poly(ADP-ribose) polymerase that affect its catalytic activity but not its DNA binding capacity. FEBS Lett 1996; 399:313-6. [PMID: 8985170 DOI: 10.1016/s0014-5793(96)01347-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Poly-ADP ribosylation of nuclear proteins is activated when poly(ADP-ribose) polymerase (PARP), a nuclear zinc-finger enzyme, binds to single-strand DNA breaks. To understand how the signal emerging from its DNA-binding domain (DBD) bound to such breaks is transduced to its catalytic domain, the structure-function relationship of the DBD was investigated. We have used mutagenesis by the polymerase chain reaction (PCR) to generate a random library of PARP mutants. In this work, we describe the identification of catalytically inactive mutants bearing single point mutations, located outside the two zinc fingers in the DBD, that have conserved their full capacity to bind DNA. The results obtained demonstrate that the DNA-dependent activation of PARP requires not only a capacity to bind DNA but also a number of crucial residues to maintain a conformation of the domain necessary to transfer an 'activation signal' to the catalytic domain.
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Affiliation(s)
- C Trucco
- Ecole Supérieure de Biotechnologie de Strasbourg, UPR A9003 du CNRS, Illkirch-Graffenstaden, France
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29
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Luisetti M, Travis J. Bioengineering: alpha 1-proteinase inhibitor site-specific mutagenesis. The prospect for improving the inhibitor. Chest 1996; 110:278S-283S. [PMID: 8989165 DOI: 10.1378/chest.110.6_supplement.278s] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
alpha 1-Proteinase inhibitor (alpha 1-PI) augmentation therapy has been licensed for treatment of alpha 1-PI-deficient individuals with pulmonary emphysema. The currently available product is purified from pooled human plasma. To obtain larger amounts of protein free from possible unknown plasma contaminants, human alpha 1-PI has been produced by recombinant DNA. Since wild-type alpha 1-PI is susceptible to oxidative impairment, several alpha 1-PI variants in which the active site oxidation-sensitive residue is replaced by inert residues have been constructed. This article is aimed at reviewing the history, biological efficacy, advantages, disadvantages, and concerns linked to alpha 1-PI recombinant DNA and site-specific mutagenesis technology.
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Affiliation(s)
- M Luisetti
- Istituto di Tisiologia e Malattie Apparato Respiratorio, Università di Pavia, Italy
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30
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Friedhoff P, Kolmes B, Gimadutdinow O, Wende W, Krause KL, Pingoud A. Analysis of the mechanism of the Serratia nuclease using site-directed mutagenesis. Nucleic Acids Res 1996; 24:2632-9. [PMID: 8758988 PMCID: PMC146012 DOI: 10.1093/nar/24.14.2632] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Based on crystal structure analysis of the Serratia nuclease and a sequence alignment of six related nucleases, conserved amino acid residues that are located in proximity to the previously identified catalytic site residue His89 were selected for a mutagenesis study. Five out of 12 amino acid residues analyzed turned out to be of particular importance for the catalytic activity of the enzyme: Arg57, Arg87, His89, Asn119 and Glu127. Their replacement by alanine, for example, resulted in mutant proteins of very low activity, < 1% of the activity of the wild-type enzyme. Steady-state kinetic analysis of the mutant proteins demonstrates that some of these mutants are predominantly affected in their kcat, others in their Km. These results and the determination of the pH and metal ion dependence of selected mutant proteins were used for a tentative assignment for the function of these amino acid residues in the mechanism of phosphodiester bond cleavage by the Serratia nuclease.
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Affiliation(s)
- P Friedhoff
- Institut für Biochemie, Justus-Liebig-Universität, Giessen, Germany
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31
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Curth U, Genschel J, Urbanke C, Greipel J. In vitro and in vivo function of the C-terminus of Escherichia coli single-stranded DNA binding protein. Nucleic Acids Res 1996; 24:2706-11. [PMID: 8759000 PMCID: PMC145992 DOI: 10.1093/nar/24.14.2706] [Citation(s) in RCA: 115] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
We constructed several deletion mutants of Escherichia coli single-stranded DNA binding protein (EcoSSB) lacking different parts of the C-terminal region. This region of EcoSSB is composed of two parts: a glycine and proline-rich sequence of approximately 60 amino acids followed by an acidic region of the last 10 amino acids which is highly conserved among the bacterial SSB proteins. The single-stranded DNA binding protein of human mitochondria (HsmtSSB) lacks a region homologous to the C-terminal third of EcoSSB. Therefore, we also investigated a chimeric protein consisting of the complete sequence of the human mitochondrial single-stranded DNA binding protein (HsmtSSB) and the C-terminal third of EcoSSB. Fluorescence titrations and DNA-melting curves showed that the C-terminal third of EcoSSB is not essential for DNA-binding in vitro. The affinity for single-stranded DNA and RNA is even increased by the removal of the last 10 amino acids. Consequently, the nucleic acid binding affinity of HsmtSSB is reduced by the addition of the C-terminus of EcoSSB. All mutant proteins lacking the last 10 amino acids are unable to substitute wild-type EcoSSB in vivo. Thus, while the nucleic acid binding properties do not depend on an intact C-terminus, this region is essential for in vivo function. Although the DNA binding properties of HsmtSSB and EcoSSB are quite similar, HsmtSSB does not function in E.coli. This failure cannot be overcome by fusing the C-terminal third of EcoSSB to HsmtSSB. Thus differences in the N-terminal parts of both proteins must be responsible for this incompatibility. None of the mutants was defective in tetramerization. However, mixed tetramers could only be formed by proteins containing the same N-terminal part. This reflects structural differences between the N-terminal parts of HsmtSSB and EcoSSB. These results indicate that the region of the last 10 amino acids, which is highly conserved among bacterial SSB proteins, is involved in essential protein-protein interactions in the E.coli cell.
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Affiliation(s)
- U Curth
- Medizinische Hochschule, Hannover, Germany
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32
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Ahrenholtz I, Lorenz MG, Wackernagel W. A conditional suicide system in Escherichia coli based on the intracellular degradation of DNA. Appl Environ Microbiol 1994; 60:3746-51. [PMID: 7986048 PMCID: PMC201882 DOI: 10.1128/aem.60.10.3746-3751.1994] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The potential risks associated with the intentional or unintentional release of genetically engineered microorganisms led to the construction of biological containment systems by which bacteria are killed in a controlled suicide process. In previously published suicide systems, cell killing was caused by proteins destroying the cell membrane or cell wall. Here a conditional cell killing system based on the intracellular degradation of cellular DNA is presented. The nuclease gene used was that of the extracellular nuclease of Serratia marcescens. The nuclease gene was deleted for the leader-coding sequence, and the truncated gene was put under the control of the lambda pL promoter. Following thermoinduction of the nuclease gene cassette in Escherichia coli, cell survival dropped to 2 x 10(-5), and more than 80% of the radioactively labeled DNA was converted to acid-soluble material within 2.5 h in the absence of cell lysis. The majority (84%) of clones which survived thermoinduced killing turned out to be as sensitive to a second thermoinduction as the original strain. The other clones showed somewhat slower killing kinetics or slightly higher final levels of survivors. The suicide system described combines the regulated killing of cells with the destruction of intracellular DNA otherwise potentially available for horizontal gene transfer processes.
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33
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Pancre V, Wolowczuk I, Guerret S, Copin MC, Delanoye A, Capron A, Auriault C. Protective effect of rSm28GST-specific T cells in schistosomiasis: role of gamma interferon. Infect Immun 1994; 62:3723-30. [PMID: 8063386 PMCID: PMC303023 DOI: 10.1128/iai.62.9.3723-3730.1994] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Immunization with a single dose of 50 micrograms of recombinant Schistosoma mansoni 28-kDa glutathione-S-transferase (rSm28GST) was able to induce a reduction in the worm burden, the number of eggs, and the degree of hepatic fibrosis as quantified by the measurement of collagen content in the liver of S. mansoni-infected mice. No relationship was found between anti-Sm28GST immunoglobulin G and immunoglobulin A titers and the levels of protection obtained. Adoptive transfers of Sm28GST-specific total, CD4+, or CD8+ T cells reproduced the protective effect obtained with the recombinant molecule. Moreover, experiments studying in vivo T-cell depletion demonstrated that anti-CD4- or anti-CD8-treated mice showed a significant decrease in the protective effect conferred, suggesting a role of the two T-cell subpopulations in the expression of Sm28GST-mediated protection against hepatic damage. Sm28GST-specific cells produced little interleukin-4 and high levels of gamma interferon. Treatment of immunized mice with anti-gamma interferon antibody totally suppressed the Sm28GST-induced protective effect and led to the rapid death of infected animals, suggesting a role for this cytokine in the expression of the protective immunity obtained after immunization with rSm28GST.
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Affiliation(s)
- V Pancre
- Centre d'Immunologie et de Biologie Parasitaire, Institut National de la Santé et de la Recherche Médicale U 167, Institut Pasteur, Lille, France
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34
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Friedhoff P, Gimadutdinow O, Pingoud A. Identification of catalytically relevant amino acids of the extracellular Serratia marcescens endonuclease by alignment-guided mutagenesis. Nucleic Acids Res 1994; 22:3280-7. [PMID: 8078761 PMCID: PMC523719 DOI: 10.1093/nar/22.16.3280] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
By sequence alignment of the extracellular Serratia marcescens nuclease with three related nucleases we have identified seven charged amino acid residues which are conserved in all four sequences. Six of these residues together with four other partially conserved His or Asp residues were changed to alanine by site-directed PCR-mediated mutagenesis using a variant of the nuclease gene in which the coding sequence of the signal peptide was replaced by the coding sequence for an N-terminal affinity tag [Met(His)6GlySer]. Four of the mutant proteins showed almost no reduction in nuclease activity but five displayed a 10- to 1000-fold reduction in activity and one (His110Ala) was inactive. Based upon these results it is suggested that the S.marcescens nuclease employs a mechanism in which His110 acts in concert with a Mg2+ ion and three carboxylates (Asp107, Glu148 and Glu232) as well as one or two basic amino acid residues (Arg108, Arg152).
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Affiliation(s)
- P Friedhoff
- Institut für Biochemie, Justus-Liebig-Universität, Giessen, Germany
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35
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Curth U, Urbanke C, Greipel J, Gerberding H, Tiranti V, Zeviani M. Single-stranded-DNA-binding proteins from human mitochondria and Escherichia coli have analogous physicochemical properties. EUROPEAN JOURNAL OF BIOCHEMISTRY 1994; 221:435-43. [PMID: 8168532 DOI: 10.1111/j.1432-1033.1994.tb18756.x] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The gene for the mature human mitochondrial single-stranded-DNA binding protein (HsmtSSB) has been transferred into a protein-overproducing vector and expressed in Escherichia coli. The protein was purified to homogeneity and its physicochemical properties were investigated. From sequence comparison, HsmtSSB shows some similarities to the N-terminal part of the single-stranded DNA-binding protein (SSB) from E. coli (EcoSSB). Hydrodynamic measurements show the protein to be tetrameric and give a sedimentation coefficient of 4.1 S corresponding to a C-terminally shortened EcoSSB. Electron-microscopic images of the free protein show a globular tetrahedral structure. Binding of poly(desoxythymidylic acid) [poly(dT)] leads to a reduction of the tryptophan fluorescence of the protein up to 96%. Fluorescence titrations with poly(dT) show apparent binding-site sizes of 50-70 nucleotides/tetramer between 0.05 M and 2 M NaCl. Binding to poly(dT) proceeds in a nearly diffusion-controlled reaction with an association-rate constant kass of 4 x 10(8) M-1s-1. The rate-limiting step is the formation of a transient complex where less than four binding sites on the protein are involved and the reshuffling of the protein on the linear matrix is fast. Electron microscopy of the complex with poly(dT) using negative staining shows a nearly random distribution of the protein between the individual poly(dT) strands. This leads to the conclusion that the binding cooperativity is low (omega < 150). The two tryptophans of HsmtSSB were replaced by threonine and tyrosine. The environment of both residues is influenced by nucleic acid binding with mutations of Trp68 strongly reducing the DNA-binding affinity of the protein.
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Affiliation(s)
- U Curth
- Medizinische Hochschule, Zentrum Biochemie, Hannover, Germany
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36
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Oguiza JA, Malumbres M, Eriani G, Pisabarro A, Mateos LM, Martin F, Martín JF. A gene encoding arginyl-tRNA synthetase is located in the upstream region of the lysA gene in Brevibacterium lactofermentum: regulation of argS-lysA cluster expression by arginine. J Bacteriol 1993; 175:7356-62. [PMID: 8226683 PMCID: PMC206880 DOI: 10.1128/jb.175.22.7356-7362.1993] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The Brevibacterium lactofermentum argS gene, which encodes an arginyl-tRNA synthetase, was identified in the upstream region of the lysA gene. The cloned gene was sequenced; it encodes a 550-amino-acid protein with an M(r) of 59,797. The deduced amino acid sequence showed 28% identical and 49% similar residues when compared with the sequence of the Escherichia coli arginyl-tRNA synthetase. The B. lactofermentum enzyme showed the highly conserved motifs of class I aminoacyl-tRNA synthetases. Expression of the argS gene in B. lactofermentum and E. coli resulted in an increase in aminoacyl-tRNA synthetase activity, correlated with the presence in sodium dodecyl sulfate-polyacrylamide gels of a clear protein band that corresponds to this enzyme. One single transcript of about 3,000 nucleotides and corresponding to the B. lactofermentum argS-lysA operon was identified. The transcription of these genes is repressed by lysine and induced by arginine, showing an interesting pattern of biosynthetic interlock between the pathways of both amino acids in corynebacteria.
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Affiliation(s)
- J A Oguiza
- Area of Microbiology, Faculty of Biology, University of León, Spain
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37
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Abstract
An expression system for alpha 1-antitrypsin in Escherichia coli was developed using a T7 RNA polymerase promoter. Addition of rifampicin to inhibit the E. coli RNA polymerase after induction of the T7 RNA polymerase gene resulted in about 30% of newly synthesized protein being alpha 1-antitrypsin. This expression system was then used to examine the effect of mutations in the hinge region of alpha 1-antitrypsin on its activity. The mutations were based on ones in antithrombin III that had previously been shown to have adverse effects on activity. Mutation of Ala347 to threonine in alpha 1-antitrypsin did not affect the kinetic behavior of the protein with trypsin or human leukocyte elastase. In contrast, mutation of Gly349 to proline converted the majority of the protein into a substrate for both proteinases. The small fraction of this mutant that was active, however, had kinetic parameters that were indistinguishable from wild-type alpha 1-antitrypsin. Cleavage within the reactive-site loop of wild-type alpha 1-antitrypsin causes a conformational change in the molecules (the S-to-R transition) and results in a marked increase in heat stability. This increase in heat stability was also seen upon cleavage within the reactive-site loops of both of the alpha 1-antitrypsin mutants. The results are discussed in terms of a kinetic mechanism for serpin-proteinase interactions, in which after the formation of an initial complex the serpin partitions between the formation of a stable complex and a cleavage reaction.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- P C Hopkins
- Department of Haematology, University of Cambridge, MRC Centre, U.K
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38
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Kordula T, Dubin A, Schooltink H, Koj A, Heinrich PC, Rose-John S. Molecular cloning and expression of an intracellular serpin: an elastase inhibitor from horse leucocytes. Biochem J 1993; 293 ( Pt 1):187-93. [PMID: 7687128 PMCID: PMC1134338 DOI: 10.1042/bj2930187] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Horse blood leucocytes contain an elastase inhibitor (HLEI) belonging to the serpin family. Poly(A)+RNA isolated from these cells was used to construct a cDNA library in lambda gt10, which was first screened with a synthetic degenerate oligonucleotide probe corresponding to the amino acid sequence of the reactive centre of the inhibitor. Three clones were obtained covering the entire coding region of the protein. Sequencing of these clones showed identity with the amino acid sequence obtained from Edman degradation of the elastase inhibitor. The coding sequence of the HLEI cDNA was cloned into the bacterial expression vector pKK233-2 and expressed in Escherichia coli cells. Transformed bacteria expressed significant amounts of the protein, which was immunoprecipitated with a specific anti-HLEI antiserum. Furthermore, HLEI expressed in bacteria inhibited the activity of elastase but not trypsin.
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Affiliation(s)
- T Kordula
- Institute of Molecular Biology, Jagiellionian University, Krakow, Poland
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39
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Pötter E, Kloppstech K. Effects of light stress on the expression of early light-inducible proteins in barley. EUROPEAN JOURNAL OF BIOCHEMISTRY 1993; 214:779-86. [PMID: 8319687 DOI: 10.1111/j.1432-1033.1993.tb17980.x] [Citation(s) in RCA: 86] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Treatment of six-day-old barley leaves with white light of high intensity, 250-2000 W/m2, leads to a linear increase in the steady-state concentrations of early light-inducible protein (ELIP) mRNA followed by an accumulation of the protein. Accumulation of ELIP mRNA, under light stress, is highest in the basal third of the leaf and declines to approximately 50% of this level in the apical segment. The amount of the accumulated protein decreases more steeply towards the tip than would be expected from mRNA levels. This finding, as well as the fact that during greening a massive accumulation of the protein starts only at a time when the steady-state concentrations of ELIP mRNA have declined to 10% of the maximal value, indicate post-transcriptional control. Accumulation is presumably achieved by stabilization of the protein. ELIP mRNA and protein levels, induced by a 2-h period of high-light stress, are lowest in the afternoon and highest at midnight and during the morning. The inducibility of ELIP by high light is therefore under diurnal control. An increase of light stress, due to application of the carotenoid-biosynthesis inhibitor norfluorazon, results in a considerable induction of ELIP mRNA and protein. The plant hormone abscisic acid exerts only a small effect on the mRNA level. In all cases studied, the light-induced increase in the amount of ELIP mRNA was accompanied by a corresponding decline in the mRNA levels for the apoprotein of the chlorophyll-a/b-binding protein. Steady-state concentrations of mRNA for the small subunit of ribulose-1,5-bisphosphate carboxylase were hardly affected under all investigated light intensities.
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Affiliation(s)
- E Pötter
- Institut für Botanik, Universität Hannover, Germany
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40
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Simonin F, Höfferer L, Panzeter P, Muller S, de Murcia G, Althaus F. The carboxyl-terminal domain of human poly(ADP-ribose) polymerase. Overproduction in Escherichia coli, large scale purification, and characterization. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(19)38671-5] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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41
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Simonin F, Poch O, Delarue M, de Murcia G. Identification of potential active-site residues in the human poly(ADP-ribose) polymerase. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(18)52907-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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42
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Carver A, Wright G, Cottom D, Cooper J, Dalrymple M, Temperley S, Udell M, Reeves D, Percy J, Scott A. Expression of human α1 antitrypsin in transgenic sheep. Cytotechnology 1992; 9:77-84. [PMID: 1369184 DOI: 10.1007/bf02521734] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
We have recently described the production of large amounts (< or = 65 grams per litre) of enzymatically active human alpha 1 antitrypsin in the milk of transgenic sheep (Wright et al., 1991). Here, we describe in more detail the expression of the human protein in the milk of these animals throughout the lactation period. Human alpha 1 antitrypsin is also found at much lower levels in the plasma of transgenic ewes before, during and after lactation. It is also detected in male plasma at very low levels. We have previously shown human alpha 1 antitrypsin purified from transgenic sheep milk to be indistinguishable from commercially available human plasma derived alpha 1 antitrypsin in terms of gross sugar content and in vitro activity. Here we extend this comparison to more detailed analyses of glycosylation state, amino-terminal sequence, pI value, and molecular weight determination by mass spectrometry.
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Affiliation(s)
- A Carver
- Pharmaceutical Proteins Ltd., Edinburgh, UK
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43
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Dietrich JB, Lorber B, Kern D. Expression of mammalian tyrosine aminotransferase in Saccharomyces cerevisiae and Escherichia coli. Purification to homogeneity and characterization of the enzyme overproduced in the bacteria. EUROPEAN JOURNAL OF BIOCHEMISTRY 1991; 201:399-407. [PMID: 1682148 DOI: 10.1111/j.1432-1033.1991.tb16297.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Rat liver tyrosine aminotransferase has been expressed in Saccharomyces cerevisiae and Escherichia coli. In yeast, the extent of production is 20-fold higher than that in rat liver after induction by dexamethasone, and reaches 250-fold higher in an E. coli strain carrying the T7 RNA polymerase transcription system. About 250 mg pure and homogeneous enzyme was obtained from 50 g transformed E. coli cells. Determination of Mr and pI, as well as analysis of N- and C-terminal amino acids, suggest that the isolated protein is native. The catalytic properties, similar to those of the enzyme from rat liver, confirm that it is fully active and that post-translational modifications in the mammalian cells are not essential for activity. Pyridoxal 5'-phosphate strongly protects the enzyme against thermal inactivation. After denaturation, 10 thiol groups, out of 16 in the polypeptide chain, react with 5,5'-dithiobis(2-nitrobenzoic acid) whereas only five or six are accessible under native conditions. Two thiols are rapidly modified with concomitant inactivation of the apoenzyme, but pyridoxal 5'-phosphate partially protects them in the holoenzyme. The results are interpreted in the light of the structure/function relationship in this enzyme.
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Affiliation(s)
- J B Dietrich
- Laboratoire de Biochimie, Centre National de la Recherche Scientifique, Strasbourg, France
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44
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Eriani G, Prevost G, Kern D, Vincendon P, Dirheimer G, Gangloff J. Cytoplasmic aspartyl-tRNA synthetase from Saccharomyces cerevisiae. Study of its functional organisation by deletion analysis. EUROPEAN JOURNAL OF BIOCHEMISTRY 1991; 200:337-43. [PMID: 1889402 DOI: 10.1111/j.1432-1033.1991.tb16190.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Aspartyl-tRNA synthetase (AspRS) from yeast, a homodimer of 125 kDa, was shortened by several residues from the C- and N-termini, via site-directed mutagenesis, to examine the contribution of the removed peptides to the enzyme properties. This study showed that the N-terminal sequence up to amino acid 70 (which confers peculiar ionic properties to the protein) is dispensable for activity. Domains located beyond amino acid 70 appeared to have increasing catalytic importance; the removal of 80 or 90 residues affected the Km values for ATP and deletions of 101 or 140 amino acids profoundly modified the physiochemical properties of AspRS, and by consequence, its structural organisation (extraction of the mutated proteins out of the cells required the presence of SDS). On the C-terminal side, very limited modifications readily affected the enzyme properties. Deletion of as few as three residues increased the Km for ATP and reduced the aminoacylation kcat as well as the thermostability of the adenylate synthesis activity; the kcat of this step was impaired after deletion of two further residues. Finally, shortening the C-terminal decapeptide completely inactivated AspRS, whilst affecting neither its affinity for tRNAAsp nor its dimerisation capacity. These data reveal the role of the C-terminal decapeptide as a determinant in both reactions catalysed by AspRS. This peptide is involved in ATP binding, stabilising the functional conformation of the amino-acid-activating domain and probably maintaining the tRNA-acceptor end in a reactive position with regard to the activated amino acid.
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Affiliation(s)
- G Eriani
- Institut de Biologie Moléculaire et Cellulaire du Centre National de la Recherche Scientifique, Strasbourg, France
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45
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Boulanger D, Reid GD, Sturrock RF, Wolowczuk I, Balloul JM, Grezel D, Pierce RJ, Otieno MF, Guerret S, Grimaud JA. Immunization of mice and baboons with the recombinant Sm28GST affects both worm viability and fecundity after experimental infection with Schistosoma mansoni. Parasite Immunol 1991; 13:473-90. [PMID: 1956696 DOI: 10.1111/j.1365-3024.1991.tb00545.x] [Citation(s) in RCA: 126] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A member of the glutathione S-transferase family, Sm28GST has previously demonstrated a good ability to protect rodents against experimental infection with Schistosoma mansoni. In order to evaluate its efficacy in a model closer to man, two different protocols of immunization with recombinant Sm28GST were tested on baboons in a large-scale trial. Three injections in the presence of aluminium hydroxide as adjuvant resulted in a significant 38% reduction in the adult worm burden together with a trend for a lower percentage of inflammatory tissue in the liver. Individual levels of protection, ranging from 0 to 80%, underlined the heterogeneity of the immune response to this purified molecule in outbred primates. On the other hand, two injections of Sm28GST in the presence of aluminium hydroxide and Bordetella pertussis reduced female schistosome fecundity by 33%, with a more pronounced effect (66%) on faecal egg output; there was also a trend, in this protocol, for decrease of the mean granuloma surface in the liver. Individual anti-Sm28GST IgG antibodies were apparently unrelated to levels of immunity, but there was partial evidence that cytophilic IgE might play a role in the immune mechanisms affecting worm viability, but not fecundity. In the mouse model, Sm28GST vaccination resulted in a lower hatching ability of tissue eggs recovered from immunized mice whereas passive transfer of specific anti-Sm28GST T-lymphocytes, one day before infection, significantly reduced the number of eggs in the liver of mice. We propose that different protocols of immunization with a recombinant molecule can impede Schistosoma mansoni worm viability and fecundity, but can also affect miracidium physiology, with important consequences for disease transmission and granuloma-derived pathology.
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Affiliation(s)
- D Boulanger
- Centre d'Immunologie et de Biologie Parasitaire, Unité Mixte INSERM 167-CNRS 624, Institut Pasteur, Lille, France
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46
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Wright G, Carver A, Cottom D, Reeves D, Scott A, Simons P, Wilmut I, Garner I, Colman A. High Level Expression of Active Human Alpha-1-Antitrypsin in the Milk of Transgenic Sheep. Nat Biotechnol 1991; 9:830-4. [PMID: 1367357 DOI: 10.1038/nbt0991-830] [Citation(s) in RCA: 189] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We describe the generation of five sheep transgenic for a fusion of the ovine beta-lactoglobulin gene promotor to the human alpha 1-antitrypsin (h alpha 1AT) genomic sequences. Four of these animals are female and one male. Analysis of the expression of h alpha 1AT in the milk of three of these females shows that all express the human protein at levels greater than 1 gram per liter. In one case initial levels exceeded 60 grams per liter and stabilized at approximately 35 grams per liter as lactation progressed. Human alpha 1AT purified from the milk of these animals appears to be fully N-glycosylated and has a biological activity indistinguishable from human plasma-derived material.
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Affiliation(s)
- G Wright
- Pharmaceutical Proteins Limited, Edinburgh, United Kingdom
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47
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Wilkinson DL, Harrison RG. Predicting the Solubility of Recombinant Proteins in Escherichia coli. Nat Biotechnol 1991; 9:443-8. [PMID: 1367308 DOI: 10.1038/nbt0591-443] [Citation(s) in RCA: 177] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We have studied the cause of inclusion body formation in Escherichia coli grown at 37 degrees C using statistical analysis of the composition of 81 proteins that do and do not form inclusion bodies. Six composition derived parameters were used. In declining order of their correlation with inclusion body formation, the parameters are charge average, turn forming residue fraction, cysteine fraction, proline fraction, hydrophilicity, and total number of residues. The correlation with inclusion body formation is strong for the first two parameters but weak for the last four. This correlation can be used to predict the probability that a protein will form inclusion bodies using only the protein's amino acid composition as the basis for the prediction.
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Affiliation(s)
- D L Wilkinson
- School of Chemical Engineering and Material Science, University of Oklahoma, Norman 73019
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48
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Bischoff R, Speck D, Lepage P, Delatre L, Ledoux C, Brown SW, Roitsch C. Purification and biochemical characterization of recombinant alpha 1-antitrypsin variants expressed in Escherichia coli. Biochemistry 1991; 30:3464-72. [PMID: 2012806 DOI: 10.1021/bi00228a017] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Site-directed variants of alpha 1-antitrypsin (alpha 1AT) expressed in a recombinant strain of Escherichia coli have been isolated with an overall process yield of 50% following tangential flow ultrafiltration, anion-exchange, immobilized metal affinity, and hydrophobic interaction chromatography. The primary structure of the purified variants including the integrity of the N- and C-termini has been verified by electrospray mass spectrometry of the intact molecules (44 kDa) for two of the variants (alpha 1AT Leu-358 and alpha 1AT Ala-357, Arg-358). Complementary classical peptide mapping and automated amino acid sequencing have verified 75% of the primary sequence of alpha 1AT Ala-357, Arg-358. Isoelectric focusing in an immobilized pH gradient revealed some microheterogeneity which proved to be reproducible from one purification batch to another. The isolated variants of alpha 1AT did not show any signs of proteolytic degradation during the purification process and proved to be fully active against their target proteases. The described process also allowed the complete removal of endotoxins from the preparations, opening the possibility to evaluate these novel protease inhibitors for their in vivo efficacy in different animal models of human disease.
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49
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Simonin F, Ménissier-de Murcia J, Poch O, Muller S, Gradwohl G, Molinete M, Penning C, Keith G, de Murcia G. Expression and site-directed mutagenesis of the catalytic domain of human poly(ADP-ribose)polymerase in Escherichia coli. Lysine 893 is critical for activity. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(17)30651-8] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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50
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Kern D, Mejdoub H, Vincendon P, Boulanger Y, Reinbolt J. The three cysteine residues of cytoplasmic aspartyl-tRNA synthetase from Saccharomyces cerevisiae are not essential for its activity. EUROPEAN JOURNAL OF BIOCHEMISTRY 1990; 193:97-103. [PMID: 2226452 DOI: 10.1111/j.1432-1033.1990.tb19309.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Cytoplasmic aspartyl-tRNA synthetase from Saccharomyces cerevisiae is a dimer made up of identical subunits (Mr 63,000) each of these containing three cysteines (residues 255, 512 and 519 in the amino acid sequence). Thiol-specific probes were used to label these cysteines and study the resulting effect of the modification on the kinetic parameters of both the ATP/PPi exchange and tRNA aminoacylation reactions. Using the classical techniques of protein chemistry it was shown that none of the three cysteines was labelled with iodoacetic acid, whilst N-ethylmaleimide and 5,5'-dithiobis(2-nitrobenzoate) reacted with Cys512 and Cys255, respectively. Only the latter modification was accompanied by a decrease in the rates of both enzyme activities whilst the Km values for the various substrates remained unaffected. Site-directed mutagenesis was also used to replace each of the three cysteines by other residues, either individually or simultaneously. For these experiments the enzyme was expressed in Escherichia coli using an expression vector bearing the structural gene in which the first 13 codons were replaced by the first 14 of the CII lambda gene. The resulting substitution in the amino-terminal part of the expressed enzyme had no effect on the kinetic parameters, compared to those of the enzyme purified from S. cerevisiae. Taking into account the consequences of such substitutions, as well as those of chemical modifications on the two reactions catalysed by the enzyme. ATP/PPi exchange and tRNA aminoacylation, it could be concluded that none of these three cysteines plays any essential role in either substrate binding or catalysis.
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Affiliation(s)
- D Kern
- Laboratoire de Biochmie, Centre National de la Recherche Scientifique, Strasbourg, France
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