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Expression of heterologous sigma factors enables functional screening of metagenomic and heterologous genomic libraries. Nat Commun 2015; 6:7045. [PMID: 25944046 PMCID: PMC4432631 DOI: 10.1038/ncomms8045] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 03/26/2015] [Indexed: 11/20/2022] Open
Abstract
A key limitation in using heterologous genomic or metagenomic libraries in functional genomics and genome engineering is the low expression of heterologous genes in screening hosts, such as Escherichia coli. To overcome this limitation, here we generate E. coli strains capable of recognizing heterologous promoters by expressing heterologous sigma factors. Among seven sigma factors tested, RpoD from Lactobacillus plantarum (Lpl) appears to be able of initiating transcription from all sources of DNA. Using the promoter GFP-trap concept, we successfully screen several heterologous and metagenomic DNA libraries, thus enlarging the genomic space that can be functionally sampled in E. coli. For an application, we show that screening fosmid-based Lpl genomic libraries in an E. coli strain with a chromosomally integrated Lpl rpoD enables the identification of Lpl genetic determinants imparting strong ethanol tolerance in E. coli. Transcriptome analysis confirms increased expression of heterologous genes in the engineered strain. Screening genomic or metagenomic libraries for interesting products or activities is often hampered by poor gene expression in a heterologous host. Here the authors show that the expression of a Lactobacillus sigma factor greatly enhances transcription of heterologous and environmental DNA in E. coli.
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152
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Signaling during Kidney Development. Cells 2015; 4:112-32. [PMID: 25867084 PMCID: PMC4493451 DOI: 10.3390/cells4020112] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Revised: 03/24/2015] [Accepted: 03/30/2015] [Indexed: 12/17/2022] Open
Abstract
The kidney plays an essential role during excretion of metabolic waste products, maintenance of key homeostasis components such as ion concentrations and hormone levels. It influences the blood pressure, composition and volume. The kidney tubule system is composed of two distinct cell populations: the nephrons forming the filtering units and the collecting duct system derived from the ureteric bud. Nephrons are composed of glomeruli that filter the blood to the Bowman’s capsule and tubular structures that reabsorb and concentrate primary urine. The collecting duct is a Wolffian duct-derived epithelial tube that concentrates and collects urine and transfers it via the renal pelvis into the bladder. The mammalian kidney function depends on the coordinated development of specific cell types within a precise architectural framework. Due to the availability of modern analysis techniques, the kidney has become a model organ defining the paradigm to study organogenesis. As kidney diseases are a problem worldwide, the understanding of mammalian kidney cells is of crucial importance to develop diagnostic tools and novel therapies. This review focuses on how the pattern of renal development is generated, how the inductive signals are regulated and what are their effects on proliferation, differentiation and morphogenesis.
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Abstract
La synthèse des protéines, également appelée traduction, est assurée dans chaque cellule par des machines moléculaires très sophistiquées : les ribosomes. Compte tenu de l’immense quantité de données biologiques à traiter, il arrive régulièrement que ces machines se bloquent et mettent en péril la survie de la cellule. Chez les bactéries, le principal processus de sauvetage des ribosomes bloqués est la trans-traduction. Il est assuré par un acide ribonucléique (ARN) hybride, l’ARN transfert-messager (ARNtm), associé à une petite protéine basique, SmpB (small protein B). Plusieurs autres systèmes de contrôle qualité ont récemment été mis en évidence, révélant un réseau de maintien de la survie cellulaire très sophistiqué. Cette machinerie du contrôle qualité de la synthèse protéique est une cible très prometteuse pour le développement de futurs antibiotiques.
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Takakura Y, Katayama S, Nagata Y. High-level expression of tamavidin 2 in human cells by codon-usage optimization. Biosci Biotechnol Biochem 2015; 79:610-6. [DOI: 10.1080/09168451.2014.991690] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Abstract
Tamavidin 2 is a fungal protein that binds to biotin with an extremely high affinity. Tamavidin 2 is superior to avidin or streptavidin in terms of its low-level non-specific binding and high-level thermal stability. However, the gene for tamavidin 2 is highly expressed in Escherichia coli but not in mammalian cells, restricting its application as an affinity tag in mammalian cells. Here, we optimized the codon usage of tamavidin 2 for human cells and found that the resultant mutant expressed tamavidin 2 at approximately 30-fold higher level compared with the native gene. The protein thus produced in human cells could be purified by iminobiotin affinity chromatography, bound tightly to biotin, and was stable at high temperature (82 °C). This powerful technology for high-level expression of tamavidin 2 in mammalian cells will be of value in evaluating various fusion proteins produced in mammalian cells for numerous applications.
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Affiliation(s)
- Yoshimitsu Takakura
- Plant Innovation Center, Japan Tobacco Inc., 700 Higashibara, Iwata, Shizuoka 438-0802, Japan
| | - Sakurako Katayama
- Plant Innovation Center, Japan Tobacco Inc., 700 Higashibara, Iwata, Shizuoka 438-0802, Japan
| | - Yuki Nagata
- Plant Innovation Center, Japan Tobacco Inc., 700 Higashibara, Iwata, Shizuoka 438-0802, Japan
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Decoding mechanisms by which silent codon changes influence protein biogenesis and function. Int J Biochem Cell Biol 2015; 64:58-74. [PMID: 25817479 DOI: 10.1016/j.biocel.2015.03.011] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 03/02/2015] [Accepted: 03/14/2015] [Indexed: 02/07/2023]
Abstract
SCOPE Synonymous codon usage has been a focus of investigation since the discovery of the genetic code and its redundancy. The occurrences of synonymous codons vary between species and within genes of the same genome, known as codon usage bias. Today, bioinformatics and experimental data allow us to compose a global view of the mechanisms by which the redundancy of the genetic code contributes to the complexity of biological systems from affecting survival in prokaryotes, to fine tuning the structure and function of proteins in higher eukaryotes. Studies analyzing the consequences of synonymous codon changes in different organisms have revealed that they impact nucleic acid stability, protein levels, structure and function without altering amino acid sequence. As such, synonymous mutations inevitably contribute to the pathogenesis of complex human diseases. Yet, fundamental questions remain unresolved regarding the impact of silent mutations in human disorders. In the present review we describe developments in this area concentrating on mechanisms by which synonymous mutations may affect protein function and human health. PURPOSE This synopsis illustrates the significance of synonymous mutations in disease pathogenesis. We review the different steps of gene expression affected by silent mutations, and assess the benefits and possible harmful effects of codon optimization applied in the development of therapeutic biologics. PHYSIOLOGICAL AND MEDICAL RELEVANCE Understanding mechanisms by which synonymous mutations contribute to complex diseases such as cancer, neurodegeneration and genetic disorders, including the limitations of codon-optimized biologics, provides insight concerning interpretation of silent variants and future molecular therapies.
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156
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Yilmaz G, Arslanyolu M. Efficient expression of codon-adapted affinity tagged super folder green fluorescent protein for synchronous protein localization and affinity purification studies in Tetrahymena thermophila. BMC Biotechnol 2015; 15:22. [PMID: 25887423 PMCID: PMC4432788 DOI: 10.1186/s12896-015-0137-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 03/18/2015] [Indexed: 11/20/2022] Open
Abstract
Background A superior Green Fluorescent Protein (GFP) mutant, known as superfolder GFP (sfGFP), is more soluble, faster folding, and is the brightest of the known GFP mutants. This study aimed to create a codon-adapted sfGFP tag (TtsfGFP) for simultaneous protein localization and affinity purification in Tetrahymena thermophila. Results In vivo fluorescence spectroscopic analyses of clones carrying a codon-adapted and 6 × His tagged TtsfGFP cassette showed approximately 2–4-fold increased fluorescence emission compared with the control groups at 3 h. Fluorescence microscopy also revealed that TtsfGFP reached its emission maxima at 100 min, which was much earlier than controls expressing EGFP and sfGFP (240 min). A T. thermophila ATP-dependent DNA ligase domain containing hypothetical gene (H) was cloned into the 3' end of 6 × His-TtsfGFP to assess the affinity/localization dual tag feature. Fluorescence microscopy of the 6 × His-TtsfGFP-H clone confirmed its localization in the macro- and micronucleus of vegetative T. thermophila. Simultaneous affinity purification of TtsfGFP and TtsfGFP-H with Ni-NTA beads was feasible, as shown by Ni-NTA purified proteins analysis by SDS-PAGE and western blotting. Conclusions We successfully codon adapted the N-terminal 6 × His-TtsfGFP tag and showed that it could be used for protein localization and affinity purification simultaneously in T. thermophila. We believe that this dual tag will advance T. thermophila studies by providing strong visual traceability of the target protein in vivo and in vitro during recombinant production of heterologous and homologous proteins. Electronic supplementary material The online version of this article (doi:10.1186/s12896-015-0137-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Gürkan Yilmaz
- Graduate School of Science, Department of Advance Technologies, Biotechnology Program, Anadolu University, Yunusemre Campus, Eskisehir, Turkey.
| | - Muhittin Arslanyolu
- Department of Biology, Faculty of Science, Anadolu University, Yunusemre Campus, Eskisehir, Turkey.
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Abstract
X-ray crystallography remains the most robust method to determine protein structure at the atomic level. However, the bottlenecks of protein expression and purification often discourage further study. In this chapter, we address the most common problems encountered at these stages. Based on our experiences in expressing and purifying antimicrobial efflux proteins, we explain how a pure and homogenous protein sample can be successfully crystallized by the vapor diffusion method. We present our current protocols and methodologies for this technique. Case studies show step-by-step how we have overcome problems related to expression and diffraction, eventually producing high-quality membrane protein crystals for structural determinations. It is our hope that a rational approach can be made of the often anecdotal process of membrane protein crystallization.
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Abstract
Owing to the degeneracy of the genetic code, a protein sequence can be encoded by many different synonymous mRNA coding sequences. Synonymous codon usage was once thought to be functionally neutral, but evidence now indicates it is shaped by evolutionary selection and affects other aspects of protein biogenesis beyond specifying the amino acid sequence of the protein. Synonymous rare codons, once thought to have only negative impacts on the speed and accuracy of translation, are now known to play an important role in diverse functions, including regulation of cotranslational folding, covalent modifications, secretion, and expression level. Mutations altering synonymous codon usage are linked to human diseases. However, much remains unknown about the molecular mechanisms connecting synonymous codon usage to efficient protein biogenesis and proper cell physiology. Here we review recent literature on the functional effects of codon usage, including bioinformatics approaches aimed at identifying general roles for synonymous codon usage.
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159
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mRNA secondary structure engineering of Thermobifida fusca endoglucanase (Cel6A) for enhanced expression in Escherichia coli. World J Microbiol Biotechnol 2015; 31:499-506. [PMID: 25617066 DOI: 10.1007/s11274-015-1806-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 01/19/2015] [Indexed: 01/21/2023]
Abstract
The sequence and structure of mRNA plays an important role in solubility and expression of the translated protein. To divulge the role of mRNA secondary structure and its thermodynamics in the expression level of the recombinant endoglucanase in Escherichia coli, 5'-end of the mRNA was thermodynamically optimized. Molecular engineering was done by introducing two silent synonymous mutations at positions +5 (UCU with UCC) and +7 (UUC with UUU) of the 5'-end of mRNA to relieve hybridization with ribosomal binding site. Two variants of glycoside hydrolase family six endoglucanase, wild type (cel6A.wt) and mutant (cel6A.mut) from Thermobifida fusca were expressed and characterized in E. coli using T7 promoter-based expression vector; pET22b(+). Enhanced expression level of engineered construct (Cel6A.mut) with ∆G = -2.7 kcal mol(-1)was observed. It showed up to ~45 % higher expression as compared to the wild type construct (Cel6A.wt) having ∆G = -7.8 kcal mol(-1) and ~25 % expression to the total cell proteins. Heterologous protein was purified by heating the recombinant E. coli BL21 (DE3) CodonPlus at 60 °C. The optimum pH for enzyme activity was six and optimum temperature was 60 °C. Maximum activity was observed 4.5 Umg(-1) on CMC. Hydrolytic activity was also observed on insoluble substrates, i.e. RAC (2.8 Umg(-1)), alkali treated bagass (1.7 Umg(-1)), filter paper (1.2 Umg(-1)) and BMCC (0.3 Umg(-1)). Metal ions affect endoglucanase activity in different ways. Only Fe(2+) exhibited 20.8 % stimulatory effects on enzyme activity. Enzyme activity was profoundly inhibited by Hg2(+) (91.8 %).
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Abstract
UNLABELLED Arenaviruses have a significant impact on public health and pose a credible biodefense threat, but the development of safe and effective arenavirus vaccines has remained elusive, and currently, no Food and Drug Administration (FDA)-licensed arenavirus vaccines are available. Here, we explored the use of a codon deoptimization (CD)-based approach as a novel strategy to develop live-attenuated arenavirus vaccines. We recoded the nucleoprotein (NP) of the prototypic arenavirus lymphocytic choriomeningitis virus (LCMV) with the least frequently used codons in mammalian cells, which caused lower LCMV NP expression levels in transfected cells that correlated with decreased NP activity in cell-based functional assays. We used reverse-genetics approaches to rescue a battery of recombinant LCMVs (rLCMVs) encoding CD NPs (rLCMV/NP(CD)) that showed attenuated growth kinetics in vitro. Moreover, experiments using the well-characterized mouse model of LCMV infection revealed that rLCMV/NP(CD1) and rLCMV/NP(CD2) were highly attenuated in vivo but, upon a single immunization, conferred complete protection against a subsequent lethal challenge with wild-type (WT) recombinant LCMV (rLCMV/WT). Both rLCMV/NP(CD1) and rLCMV/NP(CD2) were genetically and phenotypically stable during serial passages in FDA vaccine-approved Vero cells. These results provide proof of concept of the safety, efficacy, and stability of a CD-based approach for developing live-attenuated vaccine candidates against human-pathogenic arenaviruses. IMPORTANCE Several arenaviruses cause severe hemorrhagic fever in humans and pose a credible bioterrorism threat. Currently, no FDA-licensed vaccines are available to combat arenavirus infections, while antiarenaviral therapy is limited to the off-label use of ribavirin, which is only partially effective and is associated with side effects. Here, we describe the generation of recombinant versions of the prototypic arenavirus LCMV encoding codon-deoptimized viral nucleoproteins (rLCMV/NP(CD)). We identified rLCMV/NP(CD1) and rLCMV/NP(CD2) to be highly attenuated in vivo but able to confer protection against a subsequent lethal challenge with wild-type LCMV. These viruses displayed an attenuated phenotype during serial amplification passages in cultured cells. Our findings support the use of this approach for the development of safe, stable, and protective live-attenuated arenavirus vaccines.
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Borisov OV, Alvarez M, Carroll JA, Brown PW. Sequence Variants and Sequence Variant Analysis in Biotherapeutic Proteins. ACS SYMPOSIUM SERIES 2015. [DOI: 10.1021/bk-2015-1201.ch002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Oleg V. Borisov
- Novavax, Inc., Gaithersburg, Maryland 20878, United States
- Roche Group Member, Genentech, Inc., South San Francisco, California 94080, United States
- Pfizer Worldwide Research & Development, Chesterfield, Missouri 63017, United States
| | - Melissa Alvarez
- Novavax, Inc., Gaithersburg, Maryland 20878, United States
- Roche Group Member, Genentech, Inc., South San Francisco, California 94080, United States
- Pfizer Worldwide Research & Development, Chesterfield, Missouri 63017, United States
| | - James A. Carroll
- Novavax, Inc., Gaithersburg, Maryland 20878, United States
- Roche Group Member, Genentech, Inc., South San Francisco, California 94080, United States
- Pfizer Worldwide Research & Development, Chesterfield, Missouri 63017, United States
| | - Paul W. Brown
- Novavax, Inc., Gaithersburg, Maryland 20878, United States
- Roche Group Member, Genentech, Inc., South San Francisco, California 94080, United States
- Pfizer Worldwide Research & Development, Chesterfield, Missouri 63017, United States
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Arya R, Sabir JSM, Bora RS, Saini KS. Optimization of culture parameters and novel strategies to improve protein solubility. Methods Mol Biol 2015; 1258:45-63. [PMID: 25447858 DOI: 10.1007/978-1-4939-2205-5_3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The production of recombinant proteins, in soluble form in a prokaryotic expression system, still remains a challenge for the biotechnologist. Innovative strategies have been developed to improve protein solubility in various protein overexpressing hosts. In this chapter, we would focus on methods currently available and amenable to "desired modifications," such as (a) the use of molecular chaperones; (b) the optimization of culture conditions; (c) the reengineering of a variety of host strains and vectors with affinity tags; and (d) optimal promoter strengths. All these parameters are evaluated with the primary objective of increasing the solubilization of recombinant protein(s) during overexpression in Escherichia coli.
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Affiliation(s)
- Ranjana Arya
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110067, India
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163
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Yang X, Luo X, Cai X. Analysis of codon usage pattern in Taenia saginata based on a transcriptome dataset. Parasit Vectors 2014; 7:527. [PMID: 25440955 PMCID: PMC4268816 DOI: 10.1186/s13071-014-0527-1] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Accepted: 11/06/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Codon usage bias is an important evolutionary feature in a genome and has been widely documented in many genomes. Analysis of codon usage bias has significance for mRNA translation, design of transgenes, new gene discovery, and studies of molecular biology and evolution, etc. However, the information about synonymous codon usage pattern of T. saginata genome remains unclear. T. saginata is a food-borne zoonotic cestode which infects approximataely 50 million humans worldwide, and causes significant health problems to the host and considerable socio-economic losses as a consequence. In this study, synonymous codon usage in T. saginata were examined. METHODS Total RNA was isolated from T. saginata cysticerci and 91,487 unigenes were generated using Illumina sequencing technology. After filtering, the final sequence collection containing 11,399 CDSs was used for our analysis. RESULTS Neutrality analysis showed that the T. saginata had a wide GC3 distribution and a significant correlation was observed between GC12 and GC3. NC-plot showed most of genes on or close to the expected curve, but only a few points with low-ENC values were below it, suggesting that mutational bias plays a major role in shaping codon usage. The Parity Rule 2 plot (PR2) analysis showed that GC and AT were not used proportionally. We also identified twenty-three optimal codons in the T. saginata genome, all of which were ended with a G or C residue. These results suggest that mutational and selection forces are probably driving factors of codon usage bias in T. saginata genome. Meanwhile, other factors such as protein length, gene expression, GC content of genes, the hydropathicity of each protein also influence codon usage. CONCLUSIONS Here, we systematically analyzed the codon usage pattern and identified factors shaping in codon usage bias in T. saginata. Currently, no complete nuclear genome is available for codon usage analysis at the genome level in T. saginata. This is the first report to investigate codon biology in T. sagninata. Such information does not only bring about a new perspective for understanding the mechanisms of biased usage of synonymous codons but also provide useful clues for molecular genetic engineering and evolutionary studies.
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Affiliation(s)
- Xing Yang
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, PR China. .,College of Veterinary Medicine, Jilin University, Changchun, 130000, PR China.
| | - Xuenong Luo
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, PR China.
| | - Xuepeng Cai
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, PR China. .,College of Veterinary Medicine, Jilin University, Changchun, 130000, PR China.
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165
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Fang J, Zou L, Zhou X, Cheng B, Fan J. Synonymous rare arginine codons and tRNA abundance affect protein production and quality of TEV protease variant. PLoS One 2014; 9:e112254. [PMID: 25426854 PMCID: PMC4245098 DOI: 10.1371/journal.pone.0112254] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Accepted: 08/10/2014] [Indexed: 11/27/2022] Open
Abstract
It has been identified that a TEV protease (TEVp) variant, TEVp5M, displays improved solubility. Here, we constructed fifteen TEVp5M variants with one or more of six rare arginine codons in the coding sequence replaced with abundant E. coli arginine codons. These codon variants expressed in either E. coli BL21 (DE3) or Rossetta (DE3) showed different solubility and activity. Supply of rare tRNAs increased the tendency of certain codon variants to form insoluble aggregates at early induction stage, as determined by the fused S-tag. About 32% increase in soluble protein production of M5 variant with four synonymously mutated arginine codons was identified in Rossetta (DE3) cells using GFP fusion reporter, comparable to that of TEVp5M. After purification, two other codon variants from both E. coli strains exhibited less activity than TEVp5M on cleaving the native or modified recognition sequence incorporated between GST and E. coli diaminopropionate ammonialyase by enzyme-coupled assay, whereas purified M5 variant showed activity similar to the TEVp5M. Supply of rare tRNAs caused the decrease of activity of TEVp5M and M5 by about 21%. Our results revealed that engineering of highly soluble TEVp variants can be achieved by the combined mutations of amino acid residues and optimization of specific rare codons, whereas simple augment of rare tRNAs abundance resulted in partial loss of activity.
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Affiliation(s)
- Jie Fang
- Key Laboratory of Crop Biology of Anhui Province, School of Life Science, Anhui Agricultural University, Hefei, Anhui, PR China
| | - Lingling Zou
- Key Laboratory of Crop Biology of Anhui Province, School of Life Science, Anhui Agricultural University, Hefei, Anhui, PR China
| | - Xuan Zhou
- Key Laboratory of Crop Biology of Anhui Province, School of Life Science, Anhui Agricultural University, Hefei, Anhui, PR China
| | - Beijiu Cheng
- Key Laboratory of Crop Biology of Anhui Province, School of Life Science, Anhui Agricultural University, Hefei, Anhui, PR China
| | - Jun Fan
- Key Laboratory of Crop Biology of Anhui Province, School of Life Science, Anhui Agricultural University, Hefei, Anhui, PR China
- * E-mail:
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Itkonen JM, Urtti A, Bird LE, Sarkhel S. Codon optimization and factorial screening for enhanced soluble expression of human ciliary neurotrophic factor in Escherichia coli. BMC Biotechnol 2014; 14:92. [PMID: 25394427 PMCID: PMC4237735 DOI: 10.1186/s12896-014-0092-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Accepted: 10/21/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Neurotrophic factors influence survival, differentiation, proliferation and death of neuronal cells within the central nervous system. Human ciliary neurotrophic factor (hCNTF) has neuroprotective properties and is also known to influence energy balance. Consequently, hCNTF has potential therapeutic applications in neurodegenerative, obesity and diabetes related disorders. Clinical and biological applications of hCNTF necessitate a recombinant expression system to produce large amounts of functional protein in soluble form. Earlier attempts to express hCNTF in Escherichia coli (E. coli) were limited by low amounts and the need to refold from inclusion bodies. RESULTS In this report, we describe a strategy to effectively identify constructs and conditions for soluble expression of hCNTF in E. coli. Small-scale expression screening with soluble fusion tags identified many conditions that yielded soluble expression. Codon optimized 6-His-hCNTF construct showed soluble expression in all the conditions tested. Large-scale culture of the 6-His-hCNTF construct yielded high (10 - 20 fold) soluble expression (8 - 9 fold) as compared to earlier published reports. Functional activity of recombinant 6-His-hCNTF produced was confirmed by its binding to hCNTF receptor (hCNTFRα) with an EC50 = 36 nM. CONCLUSION Our results highlight the combination of codon optimization and screening soluble fusion tags as a successful strategy for high yielding soluble expression of hCNTF in E. coli. Codon optimization of the hCNTF sequence seems to be sufficient for soluble expression of hCNTF. The combined approach of codon optimization and soluble fusion tag screen can be an effective strategy for soluble expression of pharmaceutical proteins in E. coli.
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167
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Expression and in vitro functional analyses of recombinant Gam1 protein. Protein Expr Purif 2014; 105:47-53. [PMID: 25450237 DOI: 10.1016/j.pep.2014.10.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Revised: 10/01/2014] [Accepted: 10/03/2014] [Indexed: 01/28/2023]
Abstract
Gam1, an early gene product of an avian adenovirus, is essential for viral replication. Gam1 is the first viral protein found to globally inhibit cellular SUMOylation, a critical posttranslational modification that alters the function and cellular localization of proteins. The interaction details at the interface between Gam1 and its cellular targets remain unclear due to the lack of structural information. Although Gam1 has been previously characterized, the purity of the protein was not suitable for structural investigations. In the present study, the gene of Gam1 was cloned and expressed in various bacterial expression systems to obtain pure and soluble recombinant Gam1 protein for in vitro functional and structural studies. While Gam1 was insoluble in most expression systems tested, it became soluble when it was expressed as a fusion protein with trigger factor (TF), a ribosome associated bacterial chaperone, under the control of a cold shock promoter. Careful optimization indicates that both low temperature induction and the chaperone function of TF play critical roles in increasing Gam1 solubility. Soluble Gam1 was purified to homogeneity through sequential chromatography techniques. Monomeric Gam1 was obtained via size exclusion chromatography and analyzed by dynamic light scattering. The SUMOylation inhibitory function of the purified Gam1 was confirmed in an in vitro assay. These results have built the foundation for further structural investigations that will broaden our understanding of Gam1's roles in viral replication.
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168
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Baeshen NA, Baeshen MN, Sheikh A, Bora RS, Ahmed MMM, Ramadan HAI, Saini KS, Redwan EM. Cell factories for insulin production. Microb Cell Fact 2014; 13:141. [PMID: 25270715 PMCID: PMC4203937 DOI: 10.1186/s12934-014-0141-0] [Citation(s) in RCA: 140] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2014] [Accepted: 09/16/2014] [Indexed: 12/17/2022] Open
Abstract
The rapid increase in the number of diabetic patients globally and exploration of alternate insulin delivery methods such as inhalation or oral route that rely on higher doses, is bound to escalate the demand for recombinant insulin in near future. Current manufacturing technologies would be unable to meet the growing demand of affordable insulin due to limitation in production capacity and high production cost. Manufacturing of therapeutic recombinant proteins require an appropriate host organism with efficient machinery for posttranslational modifications and protein refolding. Recombinant human insulin has been produced predominantly using E. coli and Saccharomyces cerevisiae for therapeutic use in human. We would focus in this review, on various approaches that can be exploited to increase the production of a biologically active insulin and its analogues in E. coli and yeast. Transgenic plants are also very attractive expression system, which can be exploited to produce insulin in large quantities for therapeutic use in human. Plant-based expression system hold tremendous potential for high-capacity production of insulin in very cost-effective manner. Very high level of expression of biologically active proinsulin in seeds or leaves with long-term stability, offers a low-cost technology for both injectable as well as oral delivery of proinsulin.
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Affiliation(s)
- Nabih A Baeshen
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah, 21589, Saudi Arabia.
| | - Mohammed N Baeshen
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah, 21589, Saudi Arabia.
| | - Abdullah Sheikh
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah, 21589, Saudi Arabia.
| | - Roop S Bora
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah, 21589, Saudi Arabia.
| | - Mohamed Morsi M Ahmed
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah, 21589, Saudi Arabia. .,Nucleic Acids Research Department, Genetic Engineering and Biotechnology Research Institute (GEBRI), City for Scientific Research and Technology Applications, Alexandria, Egypt.
| | - Hassan A I Ramadan
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah, 21589, Saudi Arabia. .,Cell Biology Department, Genetic Engineering and Biotechnology Division, National Research Centre, Tahrir St. Dokki, Cairo, 12311, Egypt.
| | - Kulvinder Singh Saini
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah, 21589, Saudi Arabia.
| | - Elrashdy M Redwan
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah, 21589, Saudi Arabia. .,Protein Research Department, Genetic Engineering and Biotechnology Research Institute, City for Scientific Research and Applied Technology, New Borg AL-Arab, Alexandria, Egypt.
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169
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Sharma SK, Suresh MR, Wuest FR. Improved soluble expression of a single-chain antibody fragment in E. coli for targeting CA125 in epithelial ovarian cancer. Protein Expr Purif 2014; 102:27-37. [DOI: 10.1016/j.pep.2014.07.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Revised: 07/17/2014] [Accepted: 07/21/2014] [Indexed: 11/28/2022]
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170
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Pelchovich G, Nadejda S, Dana A, Tuller T, Bravo IG, Gophna U. Ribosomal mutations affecting the translation of genes that use non-optimal codons. FEBS J 2014; 281:3701-18. [PMID: 24966114 DOI: 10.1111/febs.12892] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Revised: 06/10/2014] [Accepted: 06/23/2014] [Indexed: 01/26/2023]
Abstract
Genes that are laterally acquired by a new host species often contain codons that are non-optimal to the tRNA repertoire of the new host, which may lead to insufficient translational levels. Inefficient translation can be overcome by different mechanisms, such as incremental amelioration of the coding sequence, compensatory mutations in the regulatory sequences leading to increased transcription or increase in gene copy number. However, there is also a possibility that ribosomal mutations can improve the expression of such genes. To test this hypothesis, we examined the effects of point mutations in the endogenous ribosomal proteins S12 and S5 in Escherichia coli, which are known to be involved in the decoding of the mRNA, on the efficiency of translation of exogenous genes that use non-optimal codons, in vivo. We show that an S12 mutant in E. coli is able to express exogenous genes, with non-optimal codons, to higher levels than the wild-type, and explore the mechanisms underlying this phenomenon in this mutant. Our results suggest that the transient emergence of mutants that allow efficient expression of exogenous genes with non-optimal codons could also increase the chances of fixation of laterally transferred genes.
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Affiliation(s)
- Gidi Pelchovich
- Department of Molecular Microbiology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Israel
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171
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Shi T, Wang Y, Wang Z, Wang G, Liu D, Fu J, Chen T, Zhao X. Deregulation of purine pathway in Bacillus subtilis and its use in riboflavin biosynthesis. Microb Cell Fact 2014; 13:101. [PMID: 25023436 PMCID: PMC4223553 DOI: 10.1186/s12934-014-0101-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Accepted: 07/06/2014] [Indexed: 11/15/2022] Open
Abstract
Background Purine nucleotides are essential metabolites for living organisms because they are involved in many important processes, such as nucleic acid synthesis, energy supply, and biosynthesis of several amino acids and riboflavin. Owing to the pivotal roles of purines in cell physiology, the pool of intracellular purine nucleotides must be maintained under strict control, and hence the de novo purine biosynthetic pathway is tightly regulated by transcription repression and inhibition mechanism. Deregulation of purine pathway is essential for this pathway engineering in Bacillus subtilis. Results Deregulation of purine pathway was attempted to improve purine nucleotides supply, based on a riboflavin producer B. subtilis strain with modification of its rib operon. To eliminate transcription repression, the pur operon repressor PurR and the 5’-UTR of pur operon containing a guanine-sensing riboswitch were disrupted. Quantitative RT-PCR analysis revealed that the relative transcription levels of purine genes were up-regulated about 380 times. Furthermore, site-directed mutagenesis was successfully introduced into PRPP amidotransferase (encoded by purF) to remove feedback inhibition by homologous alignment and analysis. Overexpression of the novel mutant PurF (D293V, K316Q and S400W) significantly increased PRPP amidotransferase activity and triggered a strong refractory effect on purine nucleotides mediated inhibition. Intracellular metabolite target analysis indicated that the purine nucleotides supply in engineered strains was facilitated by a stepwise gene-targeted deregulation. With these genetic manipulations, we managed to enhance the metabolic flow through purine pathway and consequently increased riboflavin production 3-fold (826.52 mg/L) in the purF-VQW mutant strain. Conclusions A sequential optimization strategy was applied to deregulate the rib operon and purine pathway of B. subtilis to create genetic diversities and to improve riboflavin production. Based on the deregulation of purine pathway at transcription and metabolic levels, an extended application is recommended for the yield of products, like inosine, guanosine, adenosine and folate which are directly stemming from purine pathway in B. subtilis.
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172
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Harris RP, Kilby PM. Amino acid misincorporation in recombinant biopharmaceutical products. Curr Opin Biotechnol 2014; 30:45-50. [PMID: 24922333 DOI: 10.1016/j.copbio.2014.05.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Accepted: 05/16/2014] [Indexed: 11/28/2022]
Abstract
Microbial and mammalian host systems have been used extensively for the production of protein biotherapeutics. Generally these systems rely on the production of a specific gene sequence encoding one therapeutic product. Analysis of these protein products over many years has proven that this was not always the case, with multiple species of the intended product being produced due to amino acid misincorporation or mistranslation during biosynthesis of the protein. This review is the first to give a comprehensive overview of the occurrence and analysis of these misincorporations. Furthermore, using the latest data on misincorporation in native human proteins we explore potential considerations for producing a specification for misincorporation for the development of a human biotherapeutic protein product in a production environment.
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Affiliation(s)
- Robert P Harris
- Syngenta, Jealott's Hill International Research Centre, Bracknell, Berks RG42 6EY, UK.
| | - Peter M Kilby
- Syngenta, Jealott's Hill International Research Centre, Bracknell, Berks RG42 6EY, UK
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173
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High-Level Expression, Purification, and Characterization of the Recombinant Grass Carp Pituitary Adenylate Cyclase-Activating Polypeptide. Biosci Biotechnol Biochem 2014; 72:1550-7. [DOI: 10.1271/bbb.80057] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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174
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Shin MC, Zhao J, Zhang J, Huang Y, He H, Wang M, Min KA, Yang VC. Recombinant TAT-gelonin fusion toxin: synthesis and characterization of heparin/protamine-regulated cell transduction. J Biomed Mater Res A 2014; 103:409-419. [PMID: 24733757 DOI: 10.1002/jbm.a.35188] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2014] [Accepted: 03/31/2014] [Indexed: 11/05/2022]
Abstract
Protein toxins, such as gelonin, are highly desirable anti-cancer drug candidates due to their unparalleled potency and repetitive reaction mechanism in inhibiting protein translation. However, for its potential application in cancer therapy, there remains the cell membrane barrier that allows permeation of only small molecules, which must be overcome. To address this challenge, we conjugated gelonin with a protein transduction domain (PTD), the TAT peptide, via genetic recombination. The chimeric TAT-gelonin fusion protein (TAT-Gel) retained equipotent N-glycosidase activity yet displayed greater cell uptake than unmodified recombinant gelonin (rGel), thereby yielding a significantly augmented cytotoxic activity. Remarkably, TAT-Gel displayed up to 177-fold lower IC₅₀ (avg. 54.3 nM) than rGel (avg. IC₅₀ : 3640 nM) in tested cell lines. This enhanced cytotoxicity, however, also raised potential toxicity concerns due to the non-selectivity of PTD in its mediated cell transduction. To solve this problem, we investigated the plausibility of regulating the cell transduction of TAT-Gel via a reversible masking using heparin and protamine. Here, we demonstrated, both in vitro and in vivo, that the cell transduction of TAT-Gel can be completely curbed with heparin and yet this heparin block can be efficiently reversed by the addition of protamine. This reversible tight regulation of the cell transduction of TAT-Gel by heparin and protamine sheds light of possible application of TAT-Gel in achieving a highly effective yet safe drug therapy for the treatment of tumors.
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Affiliation(s)
- Meong Cheol Shin
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnosis, School of Pharmacy, Tianjin Medical University, Tianjin 300070, China.,Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, 428 Church St., Ann Arbor, MI 48109, USA
| | - Jingwen Zhao
- Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, China
| | - Jian Zhang
- Biomedical Polymers Laboratory, and Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application, Department of Polymer Science and Engineering, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, 215123, China
| | - Yongzhuo Huang
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 501 Hai-ke Rd, Shanghai 201203, China
| | - Huining He
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnosis, School of Pharmacy, Tianjin Medical University, Tianjin 300070, China
| | - Mei Wang
- College of Pharmacy, Xinjiang Medical University, 393 Xinyi Road, Urumqi 830011, China
| | - Kyoung Ah Min
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, 428 Church St., Ann Arbor, MI 48109, USA
| | - Victor C Yang
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnosis, School of Pharmacy, Tianjin Medical University, Tianjin 300070, China.,Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, 428 Church St., Ann Arbor, MI 48109, USA
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175
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Rosano GL, Ceccarelli EA. Recombinant protein expression in Escherichia coli: advances and challenges. Front Microbiol 2014; 5:172. [PMID: 24860555 PMCID: PMC4029002 DOI: 10.3389/fmicb.2014.00172] [Citation(s) in RCA: 1299] [Impact Index Per Article: 129.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 03/29/2014] [Indexed: 12/28/2022] Open
Abstract
Escherichia coli is one of the organisms of choice for the production of recombinant proteins. Its use as a cell factory is well-established and it has become the most popular expression platform. For this reason, there are many molecular tools and protocols at hand for the high-level production of heterologous proteins, such as a vast catalog of expression plasmids, a great number of engineered strains and many cultivation strategies. We review the different approaches for the synthesis of recombinant proteins in E. coli and discuss recent progress in this ever-growing field.
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Affiliation(s)
- Germán L Rosano
- Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas Rosario, Argentina ; Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario Rosario, Argentina
| | - Eduardo A Ceccarelli
- Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas Rosario, Argentina ; Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario Rosario, Argentina
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176
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Characterization and reactivity of broiler chicken sera to selected recombinant Campylobacter jejuni chemotactic proteins. Arch Microbiol 2014; 196:375-83. [DOI: 10.1007/s00203-014-0969-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 02/09/2014] [Accepted: 02/24/2014] [Indexed: 10/25/2022]
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177
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Liu X, Deng R, Wang J, Wang X. COStar: A D-star Lite-based dynamic search algorithm for codon optimization. J Theor Biol 2014; 344:19-30. [DOI: 10.1016/j.jtbi.2013.11.022] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Revised: 11/24/2013] [Accepted: 11/26/2013] [Indexed: 01/29/2023]
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178
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Tanaka M, Tokuoka M, Gomi K. Effects of codon optimization on the mRNA levels of heterologous genes in filamentous fungi. Appl Microbiol Biotechnol 2014; 98:3859-67. [PMID: 24682479 DOI: 10.1007/s00253-014-5609-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Revised: 02/07/2014] [Accepted: 02/10/2014] [Indexed: 10/25/2022]
Abstract
Filamentous fungi, particularly Aspergillus species, have recently attracted attention as host organisms for recombinant protein production. Because the secretory yields of heterologous proteins are generally low compared with those of homologous proteins or proteins from closely related fungal species, several strategies to produce substantial amounts of recombinant proteins have been conducted. Codon optimization is a powerful tool for improving the production levels of heterologous proteins. Although codon optimization is generally believed to improve the translation efficiency of heterologous genes without affecting their mRNA levels, several studies have indicated that codon optimization causes an increase in the steady-state mRNA levels of heterologous genes in filamentous fungi. However, the mechanism that determines the low mRNA levels when native heterologous genes are expressed was poorly understood. We recently showed that the transcripts of heterologous genes are polyadenylated prematurely within the coding region and that the heterologous gene transcripts can be stabilized significantly by codon optimization, which is probably attributable to the prevention of premature polyadenylation in Aspergillus oryzae. In this review, we describe the detailed mechanism of premature polyadenylation and the rapid degradation of mRNA transcripts derived from heterologous genes in filamentous fungi.
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Affiliation(s)
- Mizuki Tanaka
- Department of Bioindustrial Informatics and Genomics, Laboratory of Bioindustrial Genomics, Graduate School of Agricultural Science, Tohoku University, 1-1 Tsutsumidori-Amamiyamachi, Aoba-ku, Sendai, 981-8555, Japan,
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179
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Hung YF, Valdau O, Schünke S, Stern O, Koenig BW, Willbold D, Hoffmann S. Recombinant production of the amino terminal cytoplasmic region of dengue virus non-structural protein 4A for structural studies. PLoS One 2014; 9:e86482. [PMID: 24466115 PMCID: PMC3900556 DOI: 10.1371/journal.pone.0086482] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Accepted: 12/09/2013] [Indexed: 01/17/2023] Open
Abstract
Background Dengue virus (DENV) is a mosquito-transmitted positive single strand RNA virus belonging to the Flaviviridae family. DENV causes dengue fever, currently the world's fastest-spreading tropical disease. Severe forms of the disease like dengue hemorrhagic fever and dengue shock syndrome are life-threatening. There is no specific treatment and no anti-DENV vaccines. Our recent data suggests that the amino terminal cytoplasmic region of the dengue virus non-structural protein 4A (NS4A) comprising amino acid residues 1 to 48 forms an amphipathic helix in the presence of membranes. Its amphipathic character was shown to be essential for viral replication. NMR-based structure-function analysis of the NS4A amino terminal region depends on its milligram-scale production and labeling with NMR active isotopes. Methodology/Principal Findings This report describes the optimization of a uniform procedure for the expression and purification of the wild type NS4A(1-48) peptide and a peptide derived from a replication-deficient mutant NS4A(1-48; L6E, M10E) with disrupted amphipathic nature. A codon-optimized, synthetic gene for NS4A(1-48) was expressed as a fusion with a GST-GB1 dual tag in E. coli. Tobacco etch virus (TEV) protease mediated cleavage generated NS4A(1-48) peptides without any artificial overhang. Using the described protocol up to 4 milligrams of the wild type or up to 5 milligrams of the mutant peptide were obtained from a one-liter culture. Isotopic labeling of the peptides was achieved and initial NMR spectra were recorded. Conclusions/Significance Small molecules targeting amphipathic helices in the related Hepatitis C virus were shown to inhibit viral replication, representing a new class of antiviral drugs. These findings highlight the need for an efficient procedure that provides large quantities of the amphipathic helix containing NS4A peptides. The double tag strategy presented in this manuscript answers these needs yielding amounts that are sufficient for comprehensive biophysical and structural studies, which might reveal new drug targets.
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Affiliation(s)
- Yu-Fu Hung
- Institut für Physikalische Biologie, Heinrich-Heine-Universität, Düsseldorf, Germany
| | - Olga Valdau
- Institute of Complex Systems, Structural Biochemistry (ICS-6), Forschungszentrum Jülich, Jülich, Germany
| | - Sven Schünke
- Institute of Complex Systems, Structural Biochemistry (ICS-6), Forschungszentrum Jülich, Jülich, Germany
| | - Omer Stern
- Department Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Bernd W. Koenig
- Institute of Complex Systems, Structural Biochemistry (ICS-6), Forschungszentrum Jülich, Jülich, Germany
- Institut für Physikalische Biologie, Heinrich-Heine-Universität, Düsseldorf, Germany
| | - Dieter Willbold
- Institute of Complex Systems, Structural Biochemistry (ICS-6), Forschungszentrum Jülich, Jülich, Germany
- Institut für Physikalische Biologie, Heinrich-Heine-Universität, Düsseldorf, Germany
| | - Silke Hoffmann
- Institute of Complex Systems, Structural Biochemistry (ICS-6), Forschungszentrum Jülich, Jülich, Germany
- * E-mail:
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180
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Bhardwaj A. Investigating the role of site specific synonymous variation in disease association studies. Mitochondrion 2014; 16:83-8. [PMID: 24434286 DOI: 10.1016/j.mito.2013.12.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Revised: 12/15/2013] [Accepted: 12/24/2013] [Indexed: 02/05/2023]
Abstract
Synonymous codon changes may not always be neutral indicating their significance in disease association studies, which is almost always overlooked. Synonymous substitutions may affect protein-folding rates leading to protein misfolding and aggregation. Genome wide analysis of 2301 mitochondrial genomes is performed to evaluate the significance of synonymous codons in disease association studies. The analysis revealed usage of rare codons at several sites in mitochondrial genes with rare codon usage higher for hydrophobic amino acids. The analysis suggests that variation data in association studies should be analyzed using site-specific codon usage values to infer the potential phenotypic impact of synonymous changes.
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Affiliation(s)
- Anshu Bhardwaj
- Open Source Drug Discovery Unit, Council of Scientific and Industrial Research (CSIR), Delhi 110001, India.
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181
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Guimaraes JC, Rocha M, Arkin AP, Cambray G. D-Tailor: automated analysis and design of DNA sequences. ACTA ACUST UNITED AC 2014; 30:1087-1094. [PMID: 24398007 PMCID: PMC3982154 DOI: 10.1093/bioinformatics/btt742] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Accepted: 12/17/2013] [Indexed: 11/30/2022]
Abstract
Motivation: Current advances in DNA synthesis, cloning and sequencing technologies afford high-throughput implementation of artificial sequences into living cells. However, flexible computational tools for multi-objective sequence design are lacking, limiting the potential of these technologies. Results: We developed DNA-Tailor (D-Tailor), a fully extendable software framework, for property-based design of synthetic DNA sequences. D-Tailor permits the seamless integration of multiple sequence analysis tools into a generic Monte Carlo simulation that evolves sequences toward any combination of rationally defined properties. As proof of principle, we show that D-Tailor is capable of designing sequence libraries comprising all possible combinations among three different sequence properties influencing translation efficiency in Escherichia coli. The capacity to design artificial sequences that systematically sample any given parameter space should support the implementation of more rigorous experimental designs. Availability: Source code is available for download at https://sourceforge.net/projects/dtailor/ Contact:aparkin@lbl.gov or cambray.guillaume@gmail.com Supplementary information:Supplementary data are available at Bioinformatics online (D-Tailor Tutorial).
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Affiliation(s)
- Joao C Guimaraes
- Department of Bioengineering, California Institute for Quantitative Biosciences, University of California, Berkeley, CA, 94720, USA, Computer Science and Technology Center, School of Engineering, University of Minho, Campus de Gualtar, Braga, Portugal and Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA Department of Bioengineering, California Institute for Quantitative Biosciences, University of California, Berkeley, CA, 94720, USA, Computer Science and Technology Center, School of Engineering, University of Minho, Campus de Gualtar, Braga, Portugal and Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA Department of Bioengineering, California Institute for Quantitative Biosciences, University of California, Berkeley, CA, 94720, USA, Computer Science and Technology Center, School of Engineering, University of Minho, Campus de Gualtar, Braga, Portugal and Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Miguel Rocha
- Department of Bioengineering, California Institute for Quantitative Biosciences, University of California, Berkeley, CA, 94720, USA, Computer Science and Technology Center, School of Engineering, University of Minho, Campus de Gualtar, Braga, Portugal and Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Adam P Arkin
- Department of Bioengineering, California Institute for Quantitative Biosciences, University of California, Berkeley, CA, 94720, USA, Computer Science and Technology Center, School of Engineering, University of Minho, Campus de Gualtar, Braga, Portugal and Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA Department of Bioengineering, California Institute for Quantitative Biosciences, University of California, Berkeley, CA, 94720, USA, Computer Science and Technology Center, School of Engineering, University of Minho, Campus de Gualtar, Braga, Portugal and Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA Department of Bioengineering, California Institute for Quantitative Biosciences, University of California, Berkeley, CA, 94720, USA, Computer Science and Technology Center, School of Engineering, University of Minho, Campus de Gualtar, Braga, Portugal and Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Guillaume Cambray
- Department of Bioengineering, California Institute for Quantitative Biosciences, University of California, Berkeley, CA, 94720, USA, Computer Science and Technology Center, School of Engineering, University of Minho, Campus de Gualtar, Braga, Portugal and Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
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182
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Bacterial co-expression of the α and β protomers of human l-asparaginase-3: Achieving essential N-terminal exposure of a catalytically critical threonine located in the β-subunit. Protein Expr Purif 2014; 93:1-10. [DOI: 10.1016/j.pep.2013.10.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Revised: 10/11/2013] [Accepted: 10/14/2013] [Indexed: 02/06/2023]
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183
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Abstract
Protein combinatorial libraries have become a platform technology for exploring protein sequence space for novel molecules for use in research, synthetic biology, biotechnology, and medicine. To expedite the isolation of proteins with novel/desired functions using screens and selections, high-quality approaches that generate protein libraries rich in folded and soluble structures are desirable for this goal. The binary patterning approach is a protein library design method that incorporates elements of both rational design and combinatorial diversity to specify the arrangement of polar and nonpolar amino acid residues in the context of a desired, folded tertiary structure template. An overview of the considerations necessary to design and construct binary patterned libraries of de novo and natural proteins is presented.
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Affiliation(s)
- Luke H Bradley
- Departments of Anatomy and Neurobiology, Molecular and Cellular Biochemistry, and the Center of Structural Biology, University of Kentucky College of Medicine, MN225 Chandler Medical Center, 800 Rose Street, Lexington, KY, 40536-0298, USA,
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184
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Indiveri C, Galluccio M, Scalise M, Pochini L. Strategies of bacterial over expression of membrane transporters relevant in human health: the successful case of the three members of OCTN subfamily. Mol Biotechnol 2013; 54:724-36. [PMID: 22843325 PMCID: PMC3636443 DOI: 10.1007/s12033-012-9586-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The OCTN subfamily includes OCTN1, 2, and 3 which are structurally and functionally related. These transporters are involved in maintenance of the carnitine homeostasis, which is essential in mammals for fatty acid β-oxidation, VLDL assembly, post-translational modifications, and other essential functions. Indeed, defects of these transporters lead to severe pathologies. OCTN1 and OCTN2 are expressed in many human tissues, while OCTN3 gene has been identified only in mouse and rat. The transporters mediate transport of carnitine and other substrates with different efficiencies and mechanisms. In order to over express the three proteins, a screening of many combinations of E. coli strains with plasmid constructs has been conducted. Only Rosetta(DE3) or Rosettagami2(DE3) gave significant expression. Higher protein amounts were firstly obtained with pET-41a(+) or pGEX-4T1 carrying fusion protein tags which required additional purification passages. Vectors carrying only a 6His tag, suitable for single passage purification, were preferred even though they lead to lower initial expression levels. Expressions were then increased optimizing several critical parameters. hOCTN1 was obtained with pH6EX3 in RosettaGami2(DE3)pLysS. hOCTN2 and mOCTN3 were obtained using pET-21a(+) in Rosetta(DE3). In particular, hOCTN2 was expressed only after codon bias, substituting the second triplet CGG with AAA (R2K mutant). The best growth conditions for hOCTN1 and mOCTN3 were 28 °C and 6 h of induction, while 4 h of induction for hOCTN2R2K. The proteins collected in the insoluble fraction of cell lysates, solubilized with sarkosyl, were purified by Ni-chelating chromatography. Final yield was 2.0, 3.0, or 3.5 mg/l of cell culture for mOCTN3, hOCTN1, or hOCTN2R2K. The data indicated that, in spite of the close evolutionary relations, several factors play different critical roles in bacterial expression of the three proteins, thus general criteria cannot be underlined. However, the strategy of dealing with related proteins revealed to be finally successful for over expressing all the three subfamily members.
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Affiliation(s)
- Cesare Indiveri
- Department of Cell Biology, University of Calabria, Arcavacata di Rende, Italy.
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185
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Pybus LP, James DC, Dean G, Slidel T, Hardman C, Smith A, Daramola O, Field R. Predicting the expression of recombinant monoclonal antibodies in Chinese hamster ovary cells based on sequence features of the CDR3 domain. Biotechnol Prog 2013; 30:188-97. [DOI: 10.1002/btpr.1839] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Revised: 10/27/2013] [Indexed: 11/11/2022]
Affiliation(s)
- Leon P. Pybus
- ChELSI Institute; Dept. of Chemical and Biological Engineering; University of Sheffield; Mappin Street, Sheffield S1 3JD U.K
| | - David C. James
- ChELSI Institute; Dept. of Chemical and Biological Engineering; University of Sheffield; Mappin Street, Sheffield S1 3JD U.K
| | - Greg Dean
- MedImmune Ltd.; Granta Park Cambridge CB21 6GH U.K
| | - Tim Slidel
- MedImmune Ltd.; Granta Park Cambridge CB21 6GH U.K
| | | | - Andrew Smith
- MedImmune Ltd.; Granta Park Cambridge CB21 6GH U.K
| | | | - Ray Field
- MedImmune Ltd.; Granta Park Cambridge CB21 6GH U.K
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186
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Eschenfeldt WH, Makowska-Grzyska M, Stols L, Donnelly M, Jedrzejczak R, Joachimiak A. New LIC vectors for production of proteins from genes containing rare codons. JOURNAL OF STRUCTURAL AND FUNCTIONAL GENOMICS 2013; 14:135-44. [PMID: 24057978 PMCID: PMC3933008 DOI: 10.1007/s10969-013-9163-9] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Accepted: 09/03/2013] [Indexed: 11/28/2022]
Abstract
In the effort to produce proteins coded by diverse genomes, structural genomics projects often must express genes containing codons that are rare in the production strain. To address this problem, genes expressing tRNAs corresponding to those codons are typically coexpressed from a second plasmid in the host strain, or from genes incorporated into production plasmids. Here we describe the modification of a series of LIC pMCSG vectors currently used in the high-throughput (HTP) production of proteins to include crucial tRNA genes covering rare codons for Arg (AGG/AGA) and Ile (AUA). We also present variants of these new vectors that allow analysis of ligand binding or co-expression of multiple proteins introduced through two independent LIC steps. Additionally, to accommodate the cloning of multiple large proteins, the size of the plasmids was reduced by approximately one kilobase through the removal of non-essential DNA from the base vector. Production of proteins from core vectors of this series validated the desired enhanced capabilities: higher yields of proteins expressed from genes with rare codons occurred in most cases, biotinylated derivatives enabled detailed automated ligand binding analysis, and multiple proteins introduced by dual LIC cloning were expressed successfully and in near balanced stoichiometry, allowing tandem purification of interacting proteins.
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Affiliation(s)
- William H. Eschenfeldt
- Midwest Center for Structural Genomics, Biosciences Division, Argonne National Laboratory, Argonne, Illinois 60439
| | - Magdalena Makowska-Grzyska
- Center for Structural Genomics of Infectious Diseases, Computational Institute, University of Chicago, Chicago, Illinois 60667
| | - Lucy Stols
- Midwest Center for Structural Genomics, Biosciences Division, Argonne National Laboratory, Argonne, Illinois 60439
| | - Mark Donnelly
- Midwest Center for Structural Genomics, Biosciences Division, Argonne National Laboratory, Argonne, Illinois 60439
| | - Robert Jedrzejczak
- Midwest Center for Structural Genomics, Biosciences Division, Argonne National Laboratory, Argonne, Illinois 60439
| | - Andrzej Joachimiak
- Midwest Center for Structural Genomics, Biosciences Division, Argonne National Laboratory, Argonne, Illinois 60439
- Center for Structural Genomics of Infectious Diseases, Computational Institute, University of Chicago, Chicago, Illinois 60667
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187
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Van Zyl LJ, Taylor MP, Eley K, Tuffin M, Cowan DA. Engineering pyruvate decarboxylase-mediated ethanol production in the thermophilic host Geobacillus thermoglucosidasius. Appl Microbiol Biotechnol 2013; 98:1247-59. [DOI: 10.1007/s00253-013-5380-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Revised: 10/30/2013] [Accepted: 11/02/2013] [Indexed: 11/25/2022]
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188
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Bardliving CL, Lowe AJ, Huang CJ, Manley L, Ritter G, Old L, Batt CA. Process development and production of cGMP grade Melan-A for cancer vaccine clinical trials. Protein Expr Purif 2013; 92:171-82. [PMID: 24045055 DOI: 10.1016/j.pep.2013.09.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Revised: 08/30/2013] [Accepted: 09/02/2013] [Indexed: 11/18/2022]
Abstract
Melan-A is a cancer testis antigen commonly found in melanoma, and has been shown to stimulate the body's immune response against cancerous cells. We have developed and executed a process utilizing current good manufacturing practices (cGMP) to produce the 6 times-His tagged protein in C41DE3 Escherichia coli for use in Phase I clinical trials. Approximately 11 g of purified Melan-A were produced from a 20 L fed-batch fermentation. Purification was achieved through a three column process utilizing immobilized metal affinity, anion exchange, and cation exchange chromatography with a buffer system optimized for low-solubility, high LPS binding capacity proteins. The host cell proteins, residual DNA, and endotoxin concentration were well below limits for a prescribed dose with a final purity level of 91%.
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Affiliation(s)
- Cameron L Bardliving
- Department of Biomedical Engineering, Cornell University, Ithaca, NY 14853, USA.
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189
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Kim MS, Jang JH, Kim YW. Overproduction of a thermostable 4-α-glucanotransferase by codon optimization at N-terminus region. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2013; 93:2683-2690. [PMID: 23620355 DOI: 10.1002/jsfa.6084] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2012] [Revised: 11/28/2012] [Accepted: 01/29/2013] [Indexed: 06/02/2023]
Abstract
BACKGROUND 4-α-Glucanotransferases are useful enzymes to modify starch owing to their transglycosylation activity. In this study, codon optimizations were conducted to overproduce a thermostable 4-α-glucanotransferase from Thermus thermophilus (TTαGT). RESULTS Two variants, termed TTαGT-P4CCG and TTαGT-mut6, were constructed, which have the optimized codon at the first rare codon and optimized codons at all six chosen rare codons at the N-terminus of TTαGT, respectively. In the Escherichia coli system, the expression of both optimized genes was enhanced by about 100-fold relative to that of the original gene, whereas all six mutated codons contributed to the overall enhancement of TTαGT production in Bacillus subtilis. On the basis of the αGTase activity of the crude cell extracts, relative activities of 1:2.9:5.8 were determined for TTαGT, TTαGT-P4CCG and TTαGT-mut6, respectively, in B. subtilis. In addition, the activity of TTαGT-mut6 from B. subtilis grown without antibiotics was as much as that with the antibiotics. Finally, after heat treatment, the specific activity of TTαGT-mut6 from B. subtilis was 1.5-fold greater than that from E. coli. CONCLUSION The codon-optimized TTαGT that was produced in a GRAS microorganism, B. subtilis, without the selection antibiotics is potentially useful in the food industry as a food-grade enzyme.
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Affiliation(s)
- Min-Su Kim
- Department of Food and Biotechnology, Korea University, 2511 Sejong-Ro, Sejong, 339-700, Korea
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190
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Liu Z, Feng T, Ji Q, Cong P, Chen Y, He Z. Introduction of silent mutations in a codon-optimized xylanase (xynB) results in enhanced protein expression in HEK293A cells. Biotechnol Lett 2013; 35:2105-11. [PMID: 23974494 DOI: 10.1007/s10529-013-1311-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Accepted: 07/25/2013] [Indexed: 10/26/2022]
Abstract
Xylanase is used extensively to improve feed conversion rates to enhance the performance of poultry and pigs. By expressing xylanase in simple-stomached animals, new breeds of genetically modified animals with enhanced feed conversion rates may be obtained. However, expression of heterologous proteins derived from lower organisms in mammalian cells is usually inefficient. When common codons of a ''one amino acid-one codon"-optimized xylanase from Streptomyces olivaceoviridis were replaced with rare codons, xylanase expression in human embryonic kidney 293A cells increased by 1.4- to 2.3-fold as determined by flow cytometry, western blot and enzymatic activity assay. Quantitative RT-PCR assay indicated that the enhanced expression could not be attributed to altered mRNA levels. This study provides an alternative strategy for improving expression levels of heterologous proteins in mammalian cells, which is potentially helpful for generating genetically modified animals with enhanced feed conversion ability.
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Affiliation(s)
- Zhiguo Liu
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510006, China,
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191
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Kopanic JL, Al-Mugotir M, Zach S, Das S, Grosely R, Sorgen PL. An Escherichia coli strain for expression of the connexin45 carboxyl terminus attached to the 4th transmembrane domain. Front Pharmacol 2013; 4:106. [PMID: 23986705 PMCID: PMC3750199 DOI: 10.3389/fphar.2013.00106] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Accepted: 08/07/2013] [Indexed: 11/26/2022] Open
Abstract
A major problem for structural characterization of membrane proteins, such as connexins, by nuclear magnetic resonance (NMR) occurs at the initial step of the process, the production of sufficient amounts of protein. This occurs because proteins must be expressed in minimal based media. Here, we describe an expression system for membrane proteins that significantly improves yield by addressing two common problems, cell toxicity caused by protein translation and codon bias between genomes. This work provides researchers with a cost-effective tool for NMR and other biophysical studies, to use when faced with little-to-no expression of eukaryotic membrane proteins in Escherichia coli expression systems.
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Affiliation(s)
- Jennifer L Kopanic
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center Omaha, NE, USA
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192
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Shin MC, Zhang J, David AE, Trommer WE, Kwon YM, Min KA, Kim JH, Yang VC. Chemically and biologically synthesized CPP-modified gelonin for enhanced anti-tumor activity. J Control Release 2013; 172:169-178. [PMID: 23973813 DOI: 10.1016/j.jconrel.2013.08.016] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Revised: 08/08/2013] [Accepted: 08/12/2013] [Indexed: 12/15/2022]
Abstract
The ineffectiveness of small molecule drugs against cancer has generated significant interest in more potent macromolecular agents. Gelonin, a plant-derived toxin that inhibits protein translation, has attracted much attention in this regard. Due to its inability to internalize into cells, however, gelonin exerts only limited tumoricidal effect. To overcome this cell membrane barrier, we modified gelonin, via both chemical conjugation and genetic recombination methods, with low molecular weight protamine (LMWP), a cell-penetrating peptide (CPP) which was shown to efficiently ferry various cargoes into cells. Results confirmed that gelonin-LMWP chemical conjugate (cG-L) and recombinant gelonin-LMWP chimera (rG-L) possessed N-glycosidase activity equivalent to that of unmodified recombinant gelonin (rGel); however, unlike rGel, both gelonin-LMWPs were able to internalize into cells. Cytotoxicity studies further demonstrated that cG-L and rG-L exhibited significantly improved tumoricidal effects, with IC50 values being 120-fold lower than that of rGel. Moreover, when tested against a CT26 s.c. xenograft tumor mouse model, significant inhibition of tumor growth was observed with rG-L doses as low as 2 μg/tumor, while no detectable therapeutic effects were seen with rGel at 10-fold higher doses. Overall, this study demonstrated the potential of utilizing CPP-modified gelonin as a highly potent anticancer drug to overcome limitations of current chemotherapeutic agents.
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Affiliation(s)
- Meong Cheol Shin
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnosis, School of Pharmacy, Tianjin Medical University, Tianjin 300070, China; Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, 428 Church St., Ann Arbor, 48109, USA
| | - Jian Zhang
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnosis, School of Pharmacy, Tianjin Medical University, Tianjin 300070, China; Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, 428 Church St., Ann Arbor, 48109, USA
| | - Allan E David
- Department of Chemical Engineering, Auburn University, Auburn, AL 36849, USA
| | - Wolfgang E Trommer
- Department of Chemistry, TU Kaiserslautern, P.O. Box 3049, D-67653 Kaiserslautern, Germany
| | - Young Min Kwon
- Department of Pharmaceutical Sciences, College of Pharmacy, Nova Southeastern University, 3200 S. University Dr., Ft. Lauderdale, FL 33328, USA
| | - Kyoung Ah Min
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, 428 Church St., Ann Arbor, 48109, USA
| | - Jin H Kim
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, 428 Church St., Ann Arbor, 48109, USA
| | - Victor C Yang
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnosis, School of Pharmacy, Tianjin Medical University, Tianjin 300070, China; Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, 428 Church St., Ann Arbor, 48109, USA.
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193
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Tillman GE, Simmons M, Garrish JK, Seal BS. Expression of a Clostridium perfringens genome-encoded putative N-acetylmuramoyl-L-alanine amidase as a potential antimicrobial to control the bacterium. Arch Microbiol 2013; 195:675-81. [PMID: 23934074 DOI: 10.1007/s00203-013-0916-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Revised: 07/19/2013] [Accepted: 07/21/2013] [Indexed: 02/01/2023]
Abstract
Clostridium perfringens is a gram-positive, spore-forming anaerobic bacterium that plays a substantial role in non-foodborne human, animal, and avian diseases as well as human foodborne disease. Previously discovered C. perfringens bacteriophage lytic enzyme amino acid sequences were utilized to identify putative prophage lysins or autolysins by BLAST analyses encoded by the genomes of C. perfringens isolates. A predicted N-acetylmuramoyl-L-alanine amidase or MurNAc-LAA (also known as peptidoglycan aminohydrolase, NAMLA amidase, NAMLAA, amidase 3, and peptidoglycan amidase; EC 3.5.1.28) was identified that would hydrolyze the amide bond between N-acetylmuramoyl and L-amino acids in certain cell wall glycopeptides. The gene encoding this protein was subsequently cloned from genomic DNA of a C. perfringens isolate by polymerase chain reaction, and the gene product (PlyCpAmi) was expressed to determine if it could be utilized as an antimicrobial to control the bacterium. By spot assay, lytic zones were observed for the purified amidase and the E. coli expression host cellular lysate containing the amidase gene. Turbidity reduction and plate counts of C. perfringens cultures were significantly reduced by the expressed protein and observed morphologies for cells treated with the amidase appeared vacuolated, non-intact, and injured compared to the untreated cells. Among a variety of C. perfringens strains, there was little gene sequence heterogeneity that varied from 1 to 21 nucleotide differences. The results further demonstrate that it is possible to discover lytic proteins encoded in the genomes of bacteria that could be utilized to control bacterial pathogens.
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Affiliation(s)
- Glenn E Tillman
- Poultry Microbiological Safety Research Unit, Richard B. Russell Agricultural Research Center, Agricultural Research Service, USDA, Athens, GA, 30605, USA
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194
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Caspeta L, Lara AR, Pérez NO, Flores N, Bolívar F, Ramírez OT. Enhancing thermo-induced recombinant protein production in Escherichia coli by temperature oscillations and post-induction nutrient feeding strategies. J Biotechnol 2013; 167:47-55. [DOI: 10.1016/j.jbiotec.2013.06.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Revised: 05/30/2013] [Accepted: 06/03/2013] [Indexed: 11/15/2022]
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195
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Gilabert-Oriol R, Thakur M, Weise C, Dernedde J, von Mallinckrodt B, Fuchs H, Weng A. Small structural differences of targeted anti-tumor toxins result in strong variation of protein expression. Protein Expr Purif 2013; 91:54-60. [PMID: 23867360 DOI: 10.1016/j.pep.2013.07.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Accepted: 07/08/2013] [Indexed: 10/26/2022]
Abstract
Targeted anti-tumor toxins consist of a toxic functional moiety that is chemically linked or recombinantly fused to a cell-directing ligand. Ribosome-inactivating proteins (RIPs), especially type I RIPs such as saporin or dianthin, are commonly used as toxin components. Although expression of type I RIP-based fusion proteins is well reported, the achievement of higher protein yields in heterologous expression systems through innovative strategies is of major interest. In the present study, the targeted toxins (his)saporin-EGF (SE) and (his)dianthin-EGF (DE) were expressed as fusion proteins under identical expression conditions. However, the total amount of DE was nearly two-times higher than SE. The identity of the heterologously expressed targeted toxins was confirmed by mass spectrometric studies. Their biological specific activity, monitored in real time, was almost equal. Sequence alignment shows 84% identity and a structural comparison revealed five major differences, two of which affect the secondary structure resulting in a loop (SE) to β-strand (DE) conversion and one introduces a gap in SE (after position 57). In conclusion, these structural variations resulted in different protein expression levels while codon usage and toxicity to bacteria were excluded as a cause. Minor structural differences identified in this study may be considered responsible for the protection of DE from bacterial proteases and therefore may serve as a lead to modify certain domains in type I RIP-based targeted toxins.
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Affiliation(s)
- Roger Gilabert-Oriol
- Institut Für Laboratoriumsmedizin, Klinische Chemie und Pathobiochemie, Charité - Universitätsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm 30, D-12200 Berlin, Germany
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196
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Directed evolution study unveiling key sequence factors that affect translation efficiency in Escherichia coli. J Biosci Bioeng 2013; 116:540-5. [PMID: 23790548 DOI: 10.1016/j.jbiosc.2013.05.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Revised: 05/08/2013] [Accepted: 05/08/2013] [Indexed: 11/23/2022]
Abstract
Synonymous mutations in protein coding genes significantly impact translation efficiency. We synthesized a pair of genes encoding green fluorescent protein that were separated by 160 synonymous mutations to investigate key factors that affect translation efficiency. One sequence was optimized for Escherichia coli (GFP(Eco)) and the other for Bacillus subtilis (GFP(Bsu)). When the genes were expressed in E. coli, GFP(Eco) fluoresced 12-fold stronger than GFP(Bsu), confirming the suboptimal nature of the GFP(Bsu) gene. We then employed directed evolution to improve the expression of GFP(Bsu). Random mutagenesis and DNA shuffling was used to generate mutant libraries, which were screened for fluorescence. A variant showing 6-fold fluorescence enhancement was identified, which contained a single mutation (G10A) in a rare codon for Gly-4. However, the substitution generated another type of rare codon, AGA, for Arg, suggesting that the improvement was caused by a factor other than the rare codon. We next applied saturation mutagenesis to Gly-4. The darkest variant contained a GGG codon (GFP(Bsu)-G) for Gly-4. Taking the location of the mutation into account, we hypothesized that destabilization of the mRNA secondary structure around the initiation codon improved the expression. We then randomized the nucleotide triplet in 5'-untranslated region (5'UTR) of GFP(Bsu), which is complementary to the Gly-4 codon. A variant showing 6-fold fluorescence enhancement was identified, which exhibited a destabilized secondary structure. When this 5'UTR sequence was combined with GFP(Bsu)-G, 22-fold fluorescent improvement was achieved. Collectively, the stability of the mRNA secondary structure around the initiation codon predominantly affected the translation efficiency.
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197
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Johnston C, Douarre PE, Soulimane T, Pletzer D, Weingart H, MacSharry J, Coffey A, Sleator RD, O'Mahony J. Codon optimisation to improve expression of a Mycobacterium avium ssp. paratuberculosis-specific membrane-associated antigen by Lactobacillus salivarius. Pathog Dis 2013; 68:27-38. [PMID: 23620276 DOI: 10.1111/2049-632x.12040] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Revised: 03/11/2013] [Accepted: 03/20/2013] [Indexed: 01/15/2023] Open
Abstract
Subunit and DNA-based vaccines against Mycobacterium avium ssp. paratuberculosis (MAP) attempt to overcome inherent issues associated with whole-cell formulations. However, these vaccines can be hampered by poor expression of recombinant antigens from a number of disparate hosts. The high G+C content of MAP invariably leads to a codon bias throughout gene expression. To investigate if the codon bias affects recombinant MAP antigen expression, the open reading frame of a MAP-specific antigen MptD (MAP3733c) was codon optimised for expression against a Lactobacillus salivarius host. Of the total 209 codons which constitute MAP3733c, 172 were modified resulting in a reduced G+C content from 61% for the native gene to 32.7% for the modified form. Both genes were placed under the transcriptional control of the PnisA promoter; allowing controlled heterologous expression in L. salivarius. Expression was monitored using fluorescence microscopy and microplate fluorometry via GFP tags translationally fused to the C-termini of the two MptD genes. A > 37-fold increase in expression was observed for the codon-optimised MAP3733synth variant over the native gene. Due to the low cost and improved expression achieved, codon optimisation significantly improves the potential of L. salivarius as an oral vaccine stratagem against Johne's disease.
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Affiliation(s)
- Christopher Johnston
- Department of Biological Sciences, Cork Institute of Technology, Bishopstown, Cork, Ireland
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198
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Li C, Chen Z, Meng C, Li L, Liu G. High yield expression of duck hepatitis A virus VP1 protein in Escherichia coli, and production and characterization of polyclonal antibody. J Virol Methods 2013; 191:69-75. [PMID: 23583731 DOI: 10.1016/j.jviromet.2013.04.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Revised: 03/25/2013] [Accepted: 04/04/2013] [Indexed: 10/26/2022]
Abstract
VP1 protein, the capsid protein of duck hepatitis A virus (DHAV), contains critical epitopes for inducing a protective immune response. Due to its low-level expression in Escherichia coli (E. coli), the function of this protein is poorly characterized. In this study, a codon-optimized VP1 gene was chemically synthesized in terms of the codon usage bias in E. coli and subcloned into pET32a (+) to increase its expression. The recombinant VP1 fusion protein was purified from inclusion body by Ni(2+) affinity chromatography His-Bind Resin and used to raise the rabbit anti-DHAV-VP1 polyclonal antibody. The expression of the codon-optimized VP1 gene in E. coli was significantly increased when compared to the wild-type VP1 gene, having an at least 17-fold increase. Western blot analysis showed that the recombinant protein was recognized by the rabbit anti-DHAV polyclonal antibody. Western blot also demonstrated that the rabbit anti-DHAV-VP1 polyclonal antibody could recognize the purified VP1 fusion protein specifically, and in the indirect immunofluorescent assays (IFA), the antibody was able to probe the VP1 protein in DHAV-1 infected cells. In conclusion, codon optimization increased dramatically DHAV VP1 expression in E. coli and the His-tagged VP1 fusion protein showed good antigenicity and immunogenicity.
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Affiliation(s)
- Chuanfeng Li
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, China
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199
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Charneski CA, Hurst LD. Positively charged residues are the major determinants of ribosomal velocity. PLoS Biol 2013; 11:e1001508. [PMID: 23554576 PMCID: PMC3595205 DOI: 10.1371/journal.pbio.1001508] [Citation(s) in RCA: 200] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Accepted: 02/01/2013] [Indexed: 11/18/2022] Open
Abstract
Both for understanding mechanisms of disease and for the design of transgenes, it is important to understand the determinants of ribosome velocity, as changes in the rate of translation are important for protein folding, error attenuation, and localization. While there is great variation in ribosomal occupancy along even a single transcript, what determines a ribosome's occupancy is unclear. We examine this issue using data from a ribosomal footprinting assay in yeast. While codon usage is classically considered a major determinant, we find no evidence for this. By contrast, we find that positively charged amino acids greatly retard ribosomes downstream from where they are encoded, consistent with the suggestion that positively charged residues interact with the negatively charged ribosomal exit tunnel. Such slowing is independent of and greater than the average effect owing to mRNA folding. The effect of charged amino acids is additive, with ribosomal occupancy well-predicted by a linear fit to the density of positively charged residues. We thus expect that a translated poly-A tail, encoding for positively charged lysines regardless of the reading frame, would act as a sandtrap for the ribosome, consistent with experimental data.
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Affiliation(s)
| | - Laurence D. Hurst
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
- * E-mail:
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200
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Proline availability regulates proline-4-hydroxylase synthesis and substrate uptake in proline-hydroxylating recombinant Escherichia coli. Appl Environ Microbiol 2013; 79:3091-100. [PMID: 23455348 DOI: 10.1128/aem.03640-12] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Microbial physiology plays a crucial role in whole-cell biotransformation, especially for redox reactions that depend on carbon and energy metabolism. In this study, regio- and enantio-selective proline hydroxylation with recombinant Escherichia coli expressing proline-4-hydroxylase (P4H) was investigated with respect to its interconnectivity to microbial physiology and metabolism. P4H production was found to depend on extracellular proline availability and on codon usage. Medium supplementation with proline did not alter p4h mRNA levels, indicating that P4H production depends on the availability of charged prolyl-tRNAs. Increasing the intracellular levels of soluble P4H did not result in an increase in resting cell activities above a certain threshold (depending on growth and assay temperature). Activities up to 5-fold higher were reached with permeabilized cells, confirming that host physiology and not the intracellular level of active P4H determines the achievable whole-cell proline hydroxylation activity. Metabolic flux analysis revealed that tricarboxylic acid cycle fluxes in growing biocatalytically active cells were significantly higher than proline hydroxylation rates. Remarkably, a catalysis-induced reduction of substrate uptake was observed, which correlated with reduced transcription of putA and putP, encoding proline dehydrogenase and the major proline transporter, respectively. These results provide evidence for a strong interference of catalytic activity with the regulation of proline uptake and metabolism. In terms of whole-cell biocatalyst efficiency, proline uptake and competition of P4H with proline catabolism are considered the most critical factors.
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