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- Fredriksson, A., et al.
(författare)
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Labeling of human C-peptide by conjugation with N-succinimidyl-4- F-18 fluorobenzoate
- 2001
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Ingår i: Journal of labelled compounds & radiopharmaceuticals. - : Wiley. - 0362-4803 .- 1099-1344. ; 44:7, s. 509-519
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Tidskriftsartikel (refereegranskat)abstract
- We have labeled proinsulin connecting peptide (C-peptide) with fluorine-18 (t(1/2) = 109.7min) in order to perform in vivo biodistribution and pharmacokinetic studies with position emission tomography (PET). This study reports the optimization of the conjugation labeling in the N-terminal with N-succinimidyl-4-[F-18]fluorobenzoate ([F-18]SFB). In preparative runs N-4-[F-18]fluorobenzoyl-C-peptide ([F-18]FB-C-peptide) was produced in 8-12% decay-corrected yields, counted from resolubilized [F-18]F-, in less than 5h. The specific radioactivity of [F-18]FB-C-peptide, determined using ELISA for one of the preparations, was around 70 GBq/mu mol at end of synthesis.
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| 2. |
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| 3. |
- Andersson, C., et al.
(författare)
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Simulation and verification of a Hybrid Bus
- 2000
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Ingår i: Proceedings of the 2000 IEEE Nordic workshop on power and industrial electronics, Aalborg (Denmark), 13-16 Jun 2000. ; , s. 37-41
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Konferensbidrag (refereegranskat)
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| 4. |
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| 6. |
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| 7. |
- Jonasson, P., et al.
(författare)
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Genetic design for facilitated production and recovery of recombinant proteins in Escherichia coli
- 2002
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Ingår i: Biotechnology and applied biochemistry. - 0885-4513 .- 1470-8744. ; 35, s. 91-105
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Forskningsöversikt (refereegranskat)abstract
- Genetic strategies have been used for more than two decades to improve bacterial bioprocesses and to simplify recovery procedures. Such strategies include the design of efficient expression vectors and the improvement of bacterial production strains in different ways, e.g. by deletion of protease genes or engineering for overexpression of rare-codon tRNAs, foldases or chaperones. Gene multimerization is another such principle that has proved beneficial to improve production yields. Genetic strategies have furthermore been exploited to facilitate recovery processes by adapting the product for a particular purification principle. In this area, affinity fusions have been commonly used, but other principles, such as modified isoelectric point (pI) or hydrophobic properties have also been successfully investigated. A recent drastic step forward in the use of gene technology to improve recovery processes for recombinant proteins is the introduction of combinatorial protein engineering to generate tailor-made product-specific affinity ligands. This strategy, which allows efficient recovery of a recombinant protein in its native form, is likely to be increasingly used also in industrial-scale bioprocesses, since novel protein ligands have been described that can be sanitized using common industrial cleaning-in-p lace procedures. The examples presented in this review make it evident that genetic strategies will be of utmost importance in the future for facilitating production and recovery of recombinant proteins.
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| 8. |
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| 9. |
- Jonasson, P., et al.
(författare)
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Integrated bioprocess for production of human proinsulin C-peptide via heat release of an intracellular heptameric fusion protein
- 2000
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Ingår i: Journal of Biotechnology. - 0168-1656 .- 1873-4863. ; 76:03-feb, s. 215-226
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Tidskriftsartikel (refereegranskat)abstract
- An integrated bioprocess has been developed suitable for production of recombinant peptides using a gene multimerization strategy and site-specific cleavage of the resulting gene product. The process has been used for production in E. coli of the human proinsulin C-peptide via a fusion protein BB-C7 containing seven copies of the 31-residues C-peptide monomer. The fusion protein BB-C7 was expressed at high level, 1.8 g l(-1), as a soluble gene product in the cytoplasm. A heat treatment procedure efficiently released the BB-C7 fusion protein into the culture medium. This step also served as an initial purification step by precipitating the majority of the host cell proteins, resulting in a 70% purity of the BB-C7 fusion protein. Following cationic polyelectrolyte precipitation of the nucleic acids and anion exchange chromatography, native C-peptide monomers were obtained by enzymatic cleavage at flanking arginine residues. The released C-peptide material was further purified by reversed-phase chromatography and size exclusion chromatography. The overall yield of native C-peptide at a purity exceeding 99% was 400 mg l(-1) culture, corresponding to an overall recovery of 56%. The suitability of this process also for the production of other recombinant proteins is discussed.
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