601
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Wang F, Li S, Zhao H, Bian L, Chen L, Zhang Z, Zhong X, Ma L, Yu X. Expression and Characterization of the RKOD DNA Polymerase in Pichia pastoris. PLoS One 2015; 10:e0131757. [PMID: 26134129 PMCID: PMC4489709 DOI: 10.1371/journal.pone.0131757] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 06/05/2015] [Indexed: 01/02/2023] Open
Abstract
The present study assessed high-level expression of the KOD DNA polymerase in Pichia pastoris. Thermococcus kodakaraensis KOD1 is a DNA polymerase that is widely used in PCR. The DNA coding sequence of KOD was optimized based on the codon usage bias of P. pastoris and synthesized by overlapping PCR, and the nonspecific DNA-binding protein Sso7d from the crenarchaeon Sulfolobus solfataricus was fused to the C-terminus of KOD. The resulting novel gene was cloned into a pHBM905A vector and introduced into P. pastoris GS115 for secretory expression. The yield of the target protein reached approximately 250 mg/l after a 6-d induction with 1% (v/v) methanol in shake flasks. This yield is much higher than those of other DNA polymerases expressed heterologously in Escherichia coli. The recombinant enzyme was purified, and its enzymatic features were studied. Its specific activity was 19,384 U/mg. The recombinant KOD expressed in P. pastoris exhibited excellent thermostability, extension rate and fidelity. Thus, this report provides a simple, efficient and economic approach to realize the production of a high-performance thermostable DNA polymerase on a large scale. This is the first report of the expression in yeast of a DNA polymerase for use in PCR.
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Affiliation(s)
- Fei Wang
- Hubei Collaborative Innovation Center for Green Transformation of Bio-resources, Hubei Key Laboratory of Industrial Biotechnology, College of Life Sciences, Hubei University, Wuhan, People’s Republic of China
| | - Shuntang Li
- Hubei Collaborative Innovation Center for Green Transformation of Bio-resources, Hubei Key Laboratory of Industrial Biotechnology, College of Life Sciences, Hubei University, Wuhan, People’s Republic of China
| | - Hui Zhao
- Hubei Collaborative Innovation Center for Green Transformation of Bio-resources, Hubei Key Laboratory of Industrial Biotechnology, College of Life Sciences, Hubei University, Wuhan, People’s Republic of China
| | - Lu Bian
- Hubei Collaborative Innovation Center for Green Transformation of Bio-resources, Hubei Key Laboratory of Industrial Biotechnology, College of Life Sciences, Hubei University, Wuhan, People’s Republic of China
| | - Liang Chen
- Hubei Collaborative Innovation Center for Green Transformation of Bio-resources, Hubei Key Laboratory of Industrial Biotechnology, College of Life Sciences, Hubei University, Wuhan, People’s Republic of China
| | - Zhen Zhang
- Hubei Collaborative Innovation Center for Green Transformation of Bio-resources, Hubei Key Laboratory of Industrial Biotechnology, College of Life Sciences, Hubei University, Wuhan, People’s Republic of China
| | - Xing Zhong
- Department of Bioengineering, Zhixing College of HuBei University, Wuhan, People’s Republic of China
| | - Lixin Ma
- Hubei Collaborative Innovation Center for Green Transformation of Bio-resources, Hubei Key Laboratory of Industrial Biotechnology, College of Life Sciences, Hubei University, Wuhan, People’s Republic of China
- * E-mail: (LM); (XY)
| | - Xiaolan Yu
- Hubei Collaborative Innovation Center for Green Transformation of Bio-resources, Hubei Key Laboratory of Industrial Biotechnology, College of Life Sciences, Hubei University, Wuhan, People’s Republic of China
- * E-mail: (LM); (XY)
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602
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Toxocara canis mucins among other excretory-secretory antigens induce in vitro secretion of cytokines by mouse splenocytes. Parasitol Res 2015; 114:3365-71. [PMID: 26044883 PMCID: PMC4537704 DOI: 10.1007/s00436-015-4561-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 05/27/2015] [Indexed: 12/16/2022]
Abstract
The effect of Toxocara larval antigens on cytokine secretion by mouse splenocytes was studied in vitro. Recombinant mucins were produced in Pichia pastoris yeast, and Toxocara excretory-secretory (TES) antigens were collected from in vitro culture of L2 larvae. Tc-MUC-2, Tc-MUC-3, Tc-MUC-4, and Tc-MUC-5 were expressed as glycoproteins and were specifically recognized by Toxocara canis-infected dog serum antibodies. Mouse splenocytes stimulated with recombinant mucins produced IL-5, IL-6, and TGF-β. Cell stimulation with whole TES products was more effective and resulted in secretion of IL-4, IL-5, IL-6, IL-10, and TGF-β and downregulation of TNF-α production. IFN-γ and IL-17 secretion was noted only after ConA treatment. Cells originating from infected animals produced significantly smaller amounts of these two cytokines compared to control cells, which suggests that Th1 and Th17 response in infected mice is strongly inhibited. However, splenocyte stimulation with both TES and ConA upregulated the production of IFN-γ and IL-17. This shows that TES antigens have strong immunomodulatory properties and are able to induce a broad range of effects on murine immune cells.
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603
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Bill RM, von der Haar T. Hijacked then lost in translation: the plight of the recombinant host cell in membrane protein structural biology projects. Curr Opin Struct Biol 2015; 32:147-55. [PMID: 26037971 PMCID: PMC4521084 DOI: 10.1016/j.sbi.2015.04.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Revised: 04/10/2015] [Accepted: 04/10/2015] [Indexed: 11/13/2022]
Abstract
Membrane protein structural biologists need high-quality protein for crystallisation. Recombinant proteins are central to the structural biology supply chain. Understanding quality control in protein production is an emerging trend. The roles of translation and protein folding in the host cell are examined.
Membrane protein structural biology is critically dependent upon the supply of high-quality protein. Over the last few years, the value of crystallising biochemically characterised, recombinant targets that incorporate stabilising mutations has been established. Nonetheless, obtaining sufficient yields of many recombinant membrane proteins is still a major challenge. Solutions are now emerging based on an improved understanding of recombinant host cells; as a ‘cell factory’ each cell is tasked with managing limited resources to simultaneously balance its own growth demands with those imposed by an expression plasmid. This review examines emerging insights into the role of translation and protein folding in defining high-yielding recombinant membrane protein production in a range of host cells.
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Affiliation(s)
- Roslyn M Bill
- School of Life & Health Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK.
| | - Tobias von der Haar
- Kent Fungal Group, School of Biosciences, University of Kent, Canterbury CT2 7NJ, UK
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604
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Spohner SC, Müller H, Quitmann H, Czermak P. Expression of enzymes for the usage in food and feed industry with Pichia pastoris. J Biotechnol 2015; 202:118-34. [DOI: 10.1016/j.jbiotec.2015.01.027] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Revised: 12/28/2014] [Accepted: 01/07/2015] [Indexed: 12/29/2022]
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605
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Zhang C, Ku Z, Liu Q, Wang X, Chen T, Ye X, Li D, Jin X, Huang Z. High-yield production of recombinant virus-like particles of enterovirus 71 in Pichia pastoris and their protective efficacy against oral viral challenge in mice. Vaccine 2015; 33:2335-41. [PMID: 25820068 DOI: 10.1016/j.vaccine.2015.03.034] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2014] [Revised: 02/23/2015] [Accepted: 03/12/2015] [Indexed: 11/27/2022]
Abstract
Enterovirus 71 (EV71) is one of the major causative pathogens of hand, foot and mouth disease (HFMD), which is highly prevalent in the Asia-Pacific regions. Severe HFMD cases with neurological complications and even death are often associated with EV71 infections. However, no licensed EV71 vaccine is currently available. Recombinant virus-like particles (VLPs) of EV71 have been produced and shown to be a promising vaccine candidate in preclinical studies. However, the performance of current recombinant expression systems for EV71 VLP production remains unsatisfactory with regard to VLP yield and manufacturing procedure, and thus hinders further product development. In this study, we evaluated the expression of EV71 VLPs in Pichia pastoris and determined their protective efficacy in mouse models of EV71 infections. We showed that EV71 VLPs could be produced at high levels up to 4.9% of total soluble protein in transgenic P. pastoris yeast co-expressing P1 and 3CD proteins of EV71. The resulting yeast-produced VLPs potently induced neutralizing antibodies against homologous and heterologous EV71 strains in mice. More importantly, maternal immunization with VLPs protected neonatal mice in both intraperitoneal and oral challenge experiments. Collectively, these results demonstrated the success of simple, high-yield production of EV71 VLPs in transgenic P. pastoris, thus lifting the major roadblock in commercial development of VLP-based EV71 vaccines.
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Affiliation(s)
- Chao Zhang
- Vaccine Research Center, Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Zhiqiang Ku
- Vaccine Research Center, Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Qingwei Liu
- Vaccine Research Center, Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Xiaoli Wang
- Vaccine Research Center, Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Tan Chen
- Vaccine Research Center, Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Xiaohua Ye
- Vaccine Research Center, Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Dapeng Li
- Vaccine Research Center, Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Xia Jin
- Vaccine Research Center, Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Zhong Huang
- Vaccine Research Center, Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China.
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606
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Cao X, Yu H, Chen C, Wei J, Wang P. Expression and characterization of recombinant humanized anti-HER2 single-chain antibody in Pichia pastoris for targeted cancer therapy. Biotechnol Lett 2015; 37:1347-54. [DOI: 10.1007/s10529-015-1804-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2014] [Accepted: 02/23/2015] [Indexed: 10/23/2022]
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607
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Cloning and expression of synthetic genes encoding the broad antimicrobial spectrum bacteriocins SRCAM 602, OR-7, E-760, and L-1077, by recombinant Pichia pastoris. BIOMED RESEARCH INTERNATIONAL 2015; 2015:767183. [PMID: 25821820 PMCID: PMC4363639 DOI: 10.1155/2015/767183] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Accepted: 11/02/2014] [Indexed: 02/07/2023]
Abstract
We have evaluated the cloning and functional expression of previously described broad antimicrobial spectrum bacteriocins SRCAM 602, OR-7, E-760, and L-1077, by recombinant Pichia pastoris. Synthetic genes, matching the codon usage of P. pastoris, were designed from the known mature amino acid sequence of these bacteriocins and cloned into the protein expression vector pPICZαA. The recombinant derived plasmids were linearized and transformed into competent P. pastoris X-33, and the presence of integrated plasmids into the transformed cells was confirmed by PCR and sequencing of the inserts. The antimicrobial activity, expected in supernatants of the recombinant P. pastoris producers, was purified using a multistep chromatographic procedure including ammonium sulfate precipitation, desalting by gel filtration, cation exchange-, hydrophobic interaction-, and reverse phase-chromatography (RP-FPLC). However, a measurable antimicrobial activity was only detected after the hydrophobic interaction and RP-FPLC steps of the purified supernatants. MALDI-TOF MS analysis of the antimicrobial fractions eluted from RP-FPLC revealed the existence of peptide fragments of lower and higher molecular mass than expected. MALDI-TOF/TOF MS analysis of selected peptides from eluted RP-FPLC samples with antimicrobial activity indicated the presence of peptide fragments not related to the amino acid sequence of the cloned bacteriocins.
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608
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Quo vadis? The challenges of recombinant protein folding and secretion in Pichia pastoris. Appl Microbiol Biotechnol 2015; 99:2925-38. [DOI: 10.1007/s00253-015-6470-z] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2014] [Revised: 02/05/2015] [Accepted: 02/08/2015] [Indexed: 10/23/2022]
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609
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Kim H, Yoo SJ, Kang HA. Yeast synthetic biology for the production of recombinant therapeutic proteins. FEMS Yeast Res 2015; 15:1-16. [PMID: 25130199 DOI: 10.1111/1567-1364.12195] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 05/12/2014] [Accepted: 08/05/2014] [Indexed: 11/29/2022] Open
Abstract
The production of recombinant therapeutic proteins is one of the fast-growing areas of molecular medicine and currently plays an important role in treatment of several diseases. Yeasts are unicellular eukaryotic microbial host cells that offer unique advantages in producing biopharmaceutical proteins. Yeasts are capable of robust growth on simple media, readily accommodate genetic modifications, and incorporate typical eukaryotic post-translational modifications. Saccharomyces cerevisiae is a traditional baker's yeast that has been used as a major host for the production of biopharmaceuticals; however, several nonconventional yeast species including Hansenula polymorpha, Pichia pastoris, and Yarrowia lipolytica have gained increasing attention as alternative hosts for the industrial production of recombinant proteins. In this review, we address the established and emerging genetic tools and host strains suitable for recombinant protein production in various yeast expression systems, particularly focusing on current efforts toward synthetic biology approaches in developing yeast cell factories for the production of therapeutic recombinant proteins.
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Affiliation(s)
- Hyunah Kim
- Department of Life Science, Chung-Ang University, Seoul, Korea
| | - Su Jin Yoo
- Department of Life Science, Chung-Ang University, Seoul, Korea
| | - Hyun Ah Kang
- Department of Life Science, Chung-Ang University, Seoul, Korea
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610
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Gmeiner C, Saadati A, Maresch D, Krasteva S, Frank M, Altmann F, Herwig C, Spadiut O. Development of a fed-batch process for a recombinant Pichia pastoris Δoch1 strain expressing a plant peroxidase. Microb Cell Fact 2015; 14:1. [PMID: 25567661 PMCID: PMC4335410 DOI: 10.1186/s12934-014-0183-3] [Citation(s) in RCA: 106] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2014] [Accepted: 12/18/2014] [Indexed: 02/06/2023] Open
Abstract
Pichia pastoris is a prominent host for recombinant protein production, amongst other things due to its capability of glycosylation. However, N-linked glycans on recombinant proteins get hypermannosylated, causing problems in subsequent unit operations and medical applications. Hypermannosylation is triggered by an α-1,6-mannosyltransferase called OCH1. In a recent study, we knocked out OCH1 in a recombinant P. pastoris CBS7435 MutS strain (Δoch1) expressing the biopharmaceutically relevant enzyme horseradish peroxidase. We characterized the strain in the controlled environment of a bioreactor in dynamic batch cultivations and identified the strain to be physiologically impaired. We faced cell cluster formation, cell lysis and uncontrollable foam formation. In the present study, we investigated the effects of the 3 process parameters temperature, pH and dissolved oxygen concentration on 1) cell physiology, 2) cell morphology, 3) cell lysis, 4) productivity and 5) product purity of the recombinant Δoch1 strain in a multivariate manner. Cultivation at 30°C resulted in low specific methanol uptake during adaptation and the risk of methanol accumulation during cultivation. Cell cluster formation was a function of the C-source rather than process parameters and went along with cell lysis. In terms of productivity and product purity a temperature of 20°C was highly beneficial. In summary, we determined cultivation conditions for a recombinant P. pastoris Δoch1 strain allowing high productivity and product purity.
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Affiliation(s)
- Christoph Gmeiner
- Vienna University of Technology, Institute of Chemical Engineering, Research Area Biochemical Engineering, Gumpendorfer Strasse 1a, 1060, Vienna, Austria.
| | - Amirhossein Saadati
- Vienna University of Technology, Institute of Chemical Engineering, Research Area Biochemical Engineering, Gumpendorfer Strasse 1a, 1060, Vienna, Austria.
| | - Daniel Maresch
- Department of Chemistry, University of Natural Resources and Life Sciences, Vienna, Austria.
| | - Stanimira Krasteva
- Vienna University of Technology, Institute of Chemical Engineering, Research Area Biochemical Engineering, Gumpendorfer Strasse 1a, 1060, Vienna, Austria.
| | - Manuela Frank
- Vienna University of Technology, Institute of Chemical Engineering, Research Area Biochemical Engineering, Gumpendorfer Strasse 1a, 1060, Vienna, Austria.
| | - Friedrich Altmann
- Department of Chemistry, University of Natural Resources and Life Sciences, Vienna, Austria.
| | - Christoph Herwig
- Vienna University of Technology, Institute of Chemical Engineering, Research Area Biochemical Engineering, Gumpendorfer Strasse 1a, 1060, Vienna, Austria.
| | - Oliver Spadiut
- Vienna University of Technology, Institute of Chemical Engineering, Research Area Biochemical Engineering, Gumpendorfer Strasse 1a, 1060, Vienna, Austria.
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611
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Zhan R, Mu W, Jiang B, Zhou L, Zhang T. Efficient secretion of inulin fructotransferase in Pichia pastoris using the formaldehyde dehydrogenase 1 promoter. ACTA ACUST UNITED AC 2014; 41:1783-91. [DOI: 10.1007/s10295-014-1516-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Accepted: 09/19/2014] [Indexed: 10/24/2022]
Abstract
Abstract
Inulin fructotransferase (IFTase) has received considerable attention due to its ability to catalyse inulin hydrolysis to difructose anhydride (DFA III), a natural low-calorie functional sweetener. In the present study, for the first time, we describe the expression of IFTase in Pichia pastoris under the control of the formaldehyde dehydrogenase 1 promoter (PFLD1). Using this system, we achieved efficient secretion with four substrate fed-batch strategies in a 3-L fermenter. The co-feeding induction strategy with methylamine hydrochloride and methanol achieved the maximum extracellular IFTase activity of 62.72 U mL−1, which was 3.2-fold higher than that obtained with the wild-type strain. In addition to methanol, carbon sources such as glucose and glycerol could also be utilised by PFLD1-controlled P. pastoris for IFTase production using methylamine hydrochloride induction. However, we found that glycerol and glucose should be strictly controlled at low concentrations of 0.5–1.5 % (v/v) and 1–1.5 % (w/v), respectively. The use of glycerol and glucose demonstrated that P. pastoris was also attractive for IFTase production via methanol-free cultivation strategies. This study may provide the basis for the industrial use of this recombinant IFTase for the production of DFA III.
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Affiliation(s)
- Rongrong Zhan
- grid.258151.a 0000000107081323 State Key Laboratory of Food Science and Technology Jiangnan University 1800 Lihu Avenue 214122 Wuxi Jiangsu China
| | - Wanmeng Mu
- grid.258151.a 0000000107081323 State Key Laboratory of Food Science and Technology Jiangnan University 1800 Lihu Avenue 214122 Wuxi Jiangsu China
| | - Bo Jiang
- grid.258151.a 0000000107081323 State Key Laboratory of Food Science and Technology Jiangnan University 1800 Lihu Avenue 214122 Wuxi Jiangsu China
| | - Liuming Zhou
- grid.258151.a 0000000107081323 State Key Laboratory of Food Science and Technology Jiangnan University 1800 Lihu Avenue 214122 Wuxi Jiangsu China
- Roquette America 52632 Keokuk IA USA
| | - Tao Zhang
- grid.258151.a 0000000107081323 State Key Laboratory of Food Science and Technology Jiangnan University 1800 Lihu Avenue 214122 Wuxi Jiangsu China
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612
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Spiegel H, Schinkel H, Kastilan R, Dahm P, Boes A, Scheuermayer M, Chudobová I, Maskus D, Fendel R, Schillberg S, Reimann A, Fischer R. Optimization of a multi-stage, multi-subunit malaria vaccine candidate for the production in Pichia pastoris by the identification and removal of protease cleavage sites. Biotechnol Bioeng 2014; 112:659-67. [PMID: 25335451 DOI: 10.1002/bit.25481] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Revised: 09/09/2014] [Accepted: 10/14/2014] [Indexed: 01/21/2023]
Abstract
We demonstrated the successful optimization of a recombinant multi-subunit malaria vaccine candidate protein for production in the methylotrophic yeast Pichia pastoris by the identification and subsequent removal of two protease cleavage sites. After observing protein degradation in the culture supernatant of a fed-batch fermentation, the predominant proteolytic fragment of the secreted recombinant protein was analyzed by mass spectrometry. The MS data indicated the cleavage of an amino acid sequence matching the yeast KEX2-protease consensus motif EKRE. The cleavage in this region was completely abolished by the deletion of the EKRE motif in a modified variant. This modified variant was produced, purified, and used for immunization of rabbits, inducing high antigen specific antibody titers (2 × 10(6) ). Total IgG from rabbit immune sera recognized different stages of Plasmodium falciparum parasites in immunofluorescence assays, indicating native folding of the vaccine candidate. However, the modified variant was still degraded, albeit into different fragments. Further analysis by mass spectrometry and N-terminal sequencing revealed a second cleavage site downstream of the motif PEVK. We therefore removed a 17-amino-acid stretch including the PEVK motif, resulting in the subsequent production of the full-length recombinant vaccine candidate protein without significant degradation, with a yield of 53 mg per liter culture volume. We clearly demonstrate that the proteolytic degradation of recombinant proteins by endogenous P. pastoris proteases can be prevented by the identification and removal of such cleavage sites. This strategy is particularly relevant for the production of recombinant subunit vaccines, where product yield and stability play a more important role than for the production of a stringently-defined native sequence which is necessary for most therapeutic molecules.
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Affiliation(s)
- Holger Spiegel
- Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Forckenbeckstrasse 6, Aachen, 52074, Germany.
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613
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Vriens K, Cammue BPA, Thevissen K. Antifungal plant defensins: mechanisms of action and production. Molecules 2014; 19:12280-303. [PMID: 25153857 PMCID: PMC6271847 DOI: 10.3390/molecules190812280] [Citation(s) in RCA: 147] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Revised: 07/29/2014] [Accepted: 08/04/2014] [Indexed: 12/18/2022] Open
Abstract
Plant defensins are small, cysteine-rich peptides that possess biological activity towards a broad range of organisms. Their activity is primarily directed against fungi, but bactericidal and insecticidal actions have also been reported. The mode of action of various antifungal plant defensins has been studied extensively during the last decades and several of their fungal targets have been identified to date. This review summarizes the mechanism of action of well-characterized antifungal plant defensins, including RsAFP2, MsDef1, MtDef4, NaD1 and Psd1, and points out the variety by which antifungal plant defensins affect microbial cell viability. Furthermore, this review summarizes production routes for plant defensins, either via heterologous expression or chemical synthesis. As plant defensins are generally considered non-toxic for plant and mammalian cells, they are regarded as attractive candidates for further development into novel antimicrobial agents.
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Affiliation(s)
- Kim Vriens
- Centre of Microbial and Plant Genetics, Katholieke Universiteit Leuven, Kasteelpark Arenberg 20, Heverlee 3001, Belgium
| | - Bruno P A Cammue
- Centre of Microbial and Plant Genetics, Katholieke Universiteit Leuven, Kasteelpark Arenberg 20, Heverlee 3001, Belgium.
| | - Karin Thevissen
- Centre of Microbial and Plant Genetics, Katholieke Universiteit Leuven, Kasteelpark Arenberg 20, Heverlee 3001, Belgium
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