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Komuczki D, Dutra G, Gstöttner C, Dominguez-Vega E, Jungbauer A, Satzer P. Media on-demand: Continuous reconstitution of a chemically defined media directly from solids. Biotechnol Bioeng 2021; 118:3382-3394. [PMID: 33656168 PMCID: PMC8451748 DOI: 10.1002/bit.27738] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/26/2021] [Accepted: 02/19/2021] [Indexed: 12/15/2022]
Abstract
Chemically defined media are reconstituted batchwise and stored in hold tanks until use. To avoid large hold tanks and batchwise production of media, we developed continuous on‐demand reconstitutions directly from solids consisting of a hopper and a screw conveyor capable of feeding dry powdered media with the required precision ±5% at low dosing rates of 0.171 g min−1. A commercially available dry powdered cell culture medium was continuously fed over a duration of 12 h into a mixer which was connected to a UV‐cell for monitoring and the media were compared to a batchwise production. A comparable amino acid, carbohydrate, and osmolality profile to a batchwise reconstitution could be obtained. Cell cultivation showed comparable performance of batch and continuous reconstitution for two CHO cell lines producing the antibodies adalimumab and trastuzumab on a small and benchtop scale. In‐depth analysis of the produced antibodies showed the same glycosylation pattern, other posttranslational profiles such as methionine oxidation and deamidation compared to batchwise reconstitution. Therefore, we conclude a continuous reconstitution of the medium results in the same quality of the product. A continuous on‐demand media reconstitution will impact the supply chain and significantly reduce the floor space necessary for preparation and storage.
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Affiliation(s)
- Daniel Komuczki
- Department of Biotechnology, Institute of Bioprocess Science and Engineering, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Gregory Dutra
- Department of Biotechnology, Institute of Bioprocess Science and Engineering, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Christoph Gstöttner
- Center for Proteomics and Metabolomics, Leiden University Medical Center, Leiden, Netherlands
| | - Elena Dominguez-Vega
- Center for Proteomics and Metabolomics, Leiden University Medical Center, Leiden, Netherlands
| | - Alois Jungbauer
- Department of Biotechnology, Institute of Bioprocess Science and Engineering, University of Natural Resources and Life Sciences, Vienna, Austria.,Austrian Centre of Industrial Biotechnology, Vienna, Austria
| | - Peter Satzer
- Department of Biotechnology, Institute of Bioprocess Science and Engineering, University of Natural Resources and Life Sciences, Vienna, Austria.,Austrian Centre of Industrial Biotechnology, Vienna, Austria
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2
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Hellwig M. Analysis of Protein Oxidation in Food and Feed Products. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:12870-12885. [PMID: 32237708 DOI: 10.1021/acs.jafc.0c00711] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Food and feed proteins are subject to oxidation reactions during production, processing, and storage. Several individual oxidized amino acids have been described in model systems and food; however, protein oxidation in food is still mostly assessed by the analysis of protein carbonylation. In the present review, the chemistry of protein oxidation and its implications for protein functionality, food flavor, and nutritional physiology are briefly summarized. Limitations of generic methods targeting redox-relevant functional groups and properties of typical reaction products, such as the determination of protein carbonyls and fluorescence spectroscopy, are presented. Methods for the quantitation of individual oxidation products of susceptible amino acids, such as cysteine, methionine, phenylalanine, tyrosine, and tryptophan, are reported. Special regard is paid to limitations resulting from the required hydrolysis procedures and unintended formation of the analytes during sample pretreatment. If available, results from food analysis obtained by different methods are compared. Suggestions and requirements for future works on protein oxidation in food and nutrition are given.
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Affiliation(s)
- Michael Hellwig
- Chair of Food Chemistry, Technische Universität Dresden, D-01062 Dresden, Germany
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3
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Metabonomic study of the intervention effects of Parthenolide on anti-thyroid cancer activity. J Chromatogr B Analyt Technol Biomed Life Sci 2020; 1150:122179. [PMID: 32506011 DOI: 10.1016/j.jchromb.2020.122179] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 05/01/2020] [Accepted: 05/18/2020] [Indexed: 12/12/2022]
Abstract
Thyroid cancer is the most common endocrine malignant tumor in the world, and its incidence is increasing. Although the mortality rate of thyroid cancer is low, its persistence/recurrence rate is high. In addition, some patients with thyroid cancer fail to respond to radiation. Therefore, it is urgent need to develop a novel treatment for thyroid cancer. Parthenolide (PTL), a traditional Chinese medicine Tanacetum parthenium extract, has shown encouraging effects in anti-tumor, anti-inflammatory and anti-malaria. However, it is unclear whether PTL has an anti-thyroid cancer effect and its possible mechanism of action. In the recent years, metabonomics has been widely used in tumors research to explore the pharmacological mechanism of drugs, but few studies used metabonomics to investigate the pharmacological effects of PTL in thyroid tumors. In order to comprehensively reveal the mechanism and effects of PTL on anti-thyroid tumors, metabonomics combined cell biological research methods were conducted. The results showed that PTL promote apoptosis of thyroid cancer cells (TPC-1) in a concentration-dependent manner. The metabolic differences between the PTL group and the control group were compared by metabonomics, and 31 potential metabolites were identified. These metabolites were mainly involved in the tricarboxylic acid cycle, amino acid metabolism, choline metabolism and lipid metabolism. These results implied that PTL may inhibit the proliferation and development of thyroid carcinoma by accelerating oxidation emergency response, inhibiting adenosine triphosphate (ATP) synthesis and metabolic imbalance. The results of this study revealed that PTL can be an effective and potential drug for the treatment of thyroid cancer.
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4
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Wang Z, Matthews H. Translational incorporation of modified phenylalanines and tyrosines during cell-free protein synthesis. RSC Adv 2020; 10:11013-11023. [PMID: 35495348 PMCID: PMC9050441 DOI: 10.1039/d0ra00655f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 03/09/2020] [Indexed: 01/22/2023] Open
Abstract
Inherent promiscuity of bacterial translation is demonstrated by mass spectrometric quantification of the translational incorporation of ring-substituted phenylalanines and tyrosines bearing fluoro-, hydroxyl-, methyl-, chloro- and nitro-groups in an E. coli-derived cell-free system. Competitive studies using the cell-free system show that the aminoacyl-tRNA synthetases (aaRS) have at least two orders of magnitude higher specificity for the native substrate over these structural analogues, which correlates with studies on the purified synthetase. E. coli wild-type translational machinery utilizes a range of nonproteinogenic amino acids for protein synthesis with incorporation levels greater than 95%.![]()
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Affiliation(s)
- Zhongqiang Wang
- Key Laboratory of Biocatalysis & Chiral Drug Synthesis of Guizhou Province
- Generic Drug Research Center of Guizhou Province
- School of Pharmacy
- Zunyi Medical University
- Zunyi
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5
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Zer H, Mizrahi H, Malchenko N, Avin-Wittenberg T, Klipcan L, Ostersetzer-Biran O. The Phytotoxicity of Meta-Tyrosine Is Associated With Altered Phenylalanine Metabolism and Misincorporation of This Non-Proteinogenic Phe-Analog to the Plant's Proteome. FRONTIERS IN PLANT SCIENCE 2020; 11:140. [PMID: 32210982 PMCID: PMC7069529 DOI: 10.3389/fpls.2020.00140] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 01/29/2020] [Indexed: 05/10/2023]
Abstract
Plants produce a myriad of specialized (secondary) metabolites that are highly diverse chemically, and exhibit distinct biological functions. Here, we focus on meta-tyrosine (m-tyrosine), a non-proteinogenic byproduct that is often formed by a direct oxidation of phenylalanine (Phe). Some plant species (e.g., Euphorbia myrsinites and Festuca rubra) produce and accumulate high levels of m-tyrosine in their root-tips via enzymatic pathways. Upon its release to soil, the Phe-analog, m-tyrosine, affects early post-germination development (i.e., altered root development, cotyledon or leaf chlorosis, and retarded growth) of nearby plant life. However, the molecular basis of m-tyrosine-mediated (phyto)toxicity remains, to date, insufficiently understood and are still awaiting their functional characterization. It is anticipated that upon its uptake, m-tyrosine impairs key metabolic processes, or affects essential cellular activities in the plant. Here, we provide evidences that the phytotoxic effects of m-tyrosine involve two distinct molecular pathways. These include reduced steady state levels of several amino acids, and in particularly altered biosynthesis of the phenylalanine (Phe), an essential α-amino acid, which is also required for the folding and activities of proteins. In addition, proteomic studies indicate that m-tyrosine is misincorporated in place of Phe, mainly into the plant organellar proteomes. These data are supported by analyses of adt mutants, which are affected in Phe-metabolism, as well as of var2 mutants, which lack FtsH2, a major component of the chloroplast FtsH proteolytic machinery, which show higher sensitivity to m-tyrosine. Plants treated with m-tyrosine show organellar biogenesis defects, reduced respiration and photosynthetic activities and growth and developmental defect phenotypes.
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Affiliation(s)
- Hagit Zer
- Department of Plant and Environmental Sciences, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Hila Mizrahi
- Department of Plant and Environmental Sciences, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Nikol Malchenko
- Department of Plant and Environmental Sciences, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Tamar Avin-Wittenberg
- Department of Plant and Environmental Sciences, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Liron Klipcan
- Institute of Plant Sciences, the Gilat Research Center, Agricultural Research Organization (ARO), Negev, Israel
- *Correspondence: Liron Klipcan, ; Oren Ostersetzer-Biran,
| | - Oren Ostersetzer-Biran
- Department of Plant and Environmental Sciences, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
- *Correspondence: Liron Klipcan, ; Oren Ostersetzer-Biran,
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6
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Ipson BR, Green RA, Wilson JT, Watson JN, Faull KF, Fisher AL. Tyrosine aminotransferase is involved in the oxidative stress response by metabolizing meta-tyrosine in Caenorhabditis elegans. J Biol Chem 2019; 294:9536-9554. [PMID: 31043480 PMCID: PMC6579467 DOI: 10.1074/jbc.ra118.004426] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 04/24/2019] [Indexed: 12/11/2022] Open
Abstract
Under oxidative stress conditions, hydroxyl radicals can oxidize the phenyl ring of phenylalanine, producing the abnormal tyrosine isomer meta-tyrosine (m-tyrosine). m-Tyrosine levels are commonly used as a biomarker of oxidative stress, and its accumulation has recently been reported to adversely affect cells, suggesting a direct role for m-tyrosine in oxidative stress effects. We found that the Caenorhabditis elegans ortholog of tyrosine aminotransferase (TATN-1)-the first enzyme involved in the metabolic degradation of tyrosine-is up-regulated in response to oxidative stress and directly activated by the oxidative stress-responsive transcription factor SKN-1. Worms deficient in tyrosine aminotransferase activity displayed increased sensitivity to multiple sources of oxidative stress. Biochemical assays revealed that m-tyrosine is a substrate for TATN-1-mediated deamination, suggesting that TATN-1 also metabolizes m-tyrosine. Consistent with a toxic effect of m-tyrosine and a protective function of TATN-1, tatn-1 mutant worms exhibited delayed development, marked reduction in fertility, and shortened lifespan when exposed to m-tyrosine. A forward genetic screen identified a mutation in the previously uncharacterized gene F01D4.5-homologous with human transcription factor 20 (TCF20) and retinoic acid-induced 1 (RAI1)-that suppresses the adverse phenotypes observed in m-tyrosine-treated tatn-1 mutant worms. RNA-Seq analysis of F01D4.5 mutant worms disclosed a significant reduction in the expression of specific isoforms of genes encoding ribosomal proteins, suggesting that alterations in protein synthesis or ribosome structure could diminish the adverse effects of m-tyrosine. Our findings uncover a critical role for tyrosine aminotransferase in the oxidative stress response via m-tyrosine metabolism.
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Affiliation(s)
- Brett R Ipson
- From the Department of Cell Systems and Anatomy
- the Center for Healthy Aging, and
| | - Rebecca A Green
- the Ludwig Institute for Cancer Research, San Diego, La Jolla, California 92093
| | | | | | - Kym F Faull
- the Pasarow Mass Spectrometry Laboratory, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, UCLA, Los Angeles, California 90095, and
| | - Alfred L Fisher
- the Center for Healthy Aging, and
- the Division of Geriatrics, Gerontology, and Palliative Medicine, Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229
- Geriatric Research, Education and Clinical Center (GRECC), South Texas Veterans Affairs Healthcare System, San Antonio, Texas 78229
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7
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Wong HE, Huang CJ, Zhang Z. Amino acid misincorporation in recombinant proteins. Biotechnol Adv 2017; 36:168-181. [PMID: 29107148 DOI: 10.1016/j.biotechadv.2017.10.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 09/12/2017] [Accepted: 10/24/2017] [Indexed: 11/26/2022]
Abstract
Proteins provide the molecular basis for cellular structure, catalytic activity, signal transduction, and molecular transport in biological systems. Recombinant protein expression is widely used to prepare and manufacture novel proteins that serve as the foundation of many biopharmaceutical products. However, protein translation bioprocesses are inherently prone to low-level errors. These sequence variants caused by amino acid misincorporation have been observed in both native and recombinant proteins. Protein sequence variants impact product quality, and their presence can be exacerbated through cellular stress, overexpression, and nutrient starvation. Therefore, the cell line selection process, which is used in the biopharmaceutical industry, is not only directed towards maximizing productivity, but also focuses on selecting clones which yield low sequence variant levels, thereby proactively avoiding potentially inauspicious patient safety and efficacy outcomes. Here, we summarize a number of hallmark studies aimed at understanding the mechanisms of amino acid misincorporation, as well as exacerbating factors, and mitigation strategies. We also describe key advances in analytical technologies in the identification and quantification of sequence variants, and some practical considerations when using LC-MS/MS for detecting sequence variants.
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Affiliation(s)
- H Edward Wong
- Process Development, Amgen Inc., 1 Amgen Center Drive, Thousand Oaks, CA 91320, United States
| | - Chung-Jr Huang
- Process Development, Amgen Inc., 1 Amgen Center Drive, Thousand Oaks, CA 91320, United States
| | - Zhongqi Zhang
- Process Development, Amgen Inc., 1 Amgen Center Drive, Thousand Oaks, CA 91320, United States.
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8
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Translational fidelity and mistranslation in the cellular response to stress. Nat Microbiol 2017; 2:17117. [PMID: 28836574 DOI: 10.1038/nmicrobiol.2017.117] [Citation(s) in RCA: 115] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 06/20/2017] [Indexed: 11/08/2022]
Abstract
Faithful translation of mRNA into the corresponding polypeptide is a complex multistep process, requiring accurate amino acid selection, transfer RNA (tRNA) charging and mRNA decoding on the ribosome. Key players in this process are aminoacyl-tRNA synthetases (aaRSs), which not only catalyse the attachment of cognate amino acids to their respective tRNAs, but also selectively hydrolyse incorrectly activated non-cognate amino acids and/or misaminoacylated tRNAs. This aaRS proofreading provides quality control checkpoints that exclude non-cognate amino acids during translation, and in so doing helps to prevent the formation of an aberrant proteome. However, despite the intrinsic need for high accuracy during translation, and the widespread evolutionary conservation of aaRS proofreading pathways, requirements for translation quality control vary depending on cellular physiology and changes in growth conditions, and translation errors are not always detrimental. Recent work has demonstrated that mistranslation can also be beneficial to cells, and some organisms have selected for a higher degree of mistranslation than others. The aims of this Review Article are to summarize the known mechanisms of protein translational fidelity and explore the diversity and impact of mistranslation events as a potentially beneficial response to environmental and cellular stress.
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9
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Moghal A, Hwang L, Faull K, Ibba M. Multiple Quality Control Pathways Limit Non-protein Amino Acid Use by Yeast Cytoplasmic Phenylalanyl-tRNA Synthetase. J Biol Chem 2016; 291:15796-805. [PMID: 27226603 DOI: 10.1074/jbc.m116.726828] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Indexed: 11/06/2022] Open
Abstract
Non-protein amino acids, particularly isomers of the proteinogenic amino acids, present a threat to proteome integrity if they are mistakenly inserted into proteins. Quality control during aminoacyl-tRNA synthesis reduces non-protein amino acid incorporation by both substrate discrimination and proofreading. For example phenylalanyl-tRNA synthetase (PheRS) proofreads the non-protein hydroxylated phenylalanine derivative m-Tyr after its attachment to tRNA(Phe) We now show in Saccharomyces cerevisiae that PheRS misacylation of tRNA(Phe) with the more abundant Phe oxidation product o-Tyr is limited by kinetic discrimination against o-Tyr-AMP in the transfer step followed by o-Tyr-AMP release from the synthetic active site. This selective rejection of a non-protein aminoacyl-adenylate is in addition to known kinetic discrimination against certain non-cognates in the activation step as well as catalytic hydrolysis of mispaired aminoacyl-tRNA(Phe) species. We also report an unexpected resistance to cytotoxicity by a S. cerevisiae mutant with ablated post-transfer editing activity when supplemented with o-Tyr, cognate Phe, or Ala, the latter of which is not a substrate for activation by this enzyme. Our phenotypic, metabolomic, and kinetic analyses indicate at least three modes of discrimination against non-protein amino acids by S. cerevisiae PheRS and support a non-canonical role for SccytoPheRS post-transfer editing in response to amino acid stress.
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Affiliation(s)
- Adil Moghal
- From the Ohio State Biochemistry Program, Department of Microbiology, The Ohio State University, Columbus, Ohio 43210 and
| | - Lin Hwang
- Pasarow Mass Spectrometry Laboratory, Semel Institute of Neuroscience and Human Behavior, University of California, Los Angeles, California 90095
| | - Kym Faull
- Pasarow Mass Spectrometry Laboratory, Semel Institute of Neuroscience and Human Behavior, University of California, Los Angeles, California 90095
| | - Michael Ibba
- From the Ohio State Biochemistry Program, Department of Microbiology, The Ohio State University, Columbus, Ohio 43210 and
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10
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Salazar A, Keusgen M, von Hagen J. Amino acids in the cultivation of mammalian cells. Amino Acids 2016; 48:1161-71. [PMID: 26832172 PMCID: PMC4833841 DOI: 10.1007/s00726-016-2181-8] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2016] [Accepted: 01/18/2016] [Indexed: 11/29/2022]
Abstract
Amino acids are crucial for the cultivation of mammalian cells. This importance of amino acids was realized soon after the development of the first cell lines, and a solution of a mixture of amino acids has been supplied to cultured cells ever since. The importance of amino acids is further pronounced in chemically defined mammalian cell culture media, making the consideration of their biological and chemical properties necessary. Amino acids concentrations have been traditionally adjusted to their cellular consumption rates. However, since changes in the metabolic equilibrium of amino acids can be caused by changes in extracellular concentrations, metabolomics in conjunction with flux balance analysis is being used in the development of culture media. The study of amino acid transporters is also gaining importance since they control the intracellular concentrations of these molecules and are influenced by conditions in cell culture media. A better understanding of the solubility, stability, dissolution kinetics, and interactions of these molecules is needed for an exploitation of these properties in the development of dry powdered chemically defined media for mammalian cells. Due to the complexity of these mixtures however, this has proven to be challenging. Studying amino acids in mammalian cell culture media will help provide a better understanding of how mammalian cells in culture interact with their environment. It would also provide insight into the chemical behavior of these molecules in solutions of complex mixtures, which is important in the understanding of the contribution of individual amino acids to protein structure.
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Affiliation(s)
- Andrew Salazar
- Institute of Pharmaceutical Chemistry, University of Marburg, 35032, Marburg, Germany.
- Biopharm Materials & Technologies R&D, Merck Lifescience, 64293, Darmstadt, Germany.
| | - Michael Keusgen
- Institute of Pharmaceutical Chemistry, University of Marburg, 35032, Marburg, Germany
| | - Jörg von Hagen
- Biopharm Materials & Technologies R&D, Merck Lifescience, 64293, Darmstadt, Germany
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11
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Ipson BR, Fisher AL. Roles of the tyrosine isomers meta-tyrosine and ortho-tyrosine in oxidative stress. Ageing Res Rev 2016; 27:93-107. [PMID: 27039887 DOI: 10.1016/j.arr.2016.03.005] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 03/20/2016] [Accepted: 03/30/2016] [Indexed: 12/11/2022]
Abstract
The damage to cellular components by reactive oxygen species, termed oxidative stress, both increases with age and likely contributes to age-related diseases including Alzheimer's disease, atherosclerosis, diabetes, and cataract formation. In the setting of oxidative stress, hydroxyl radicals can oxidize the benzyl ring of the amino acid phenylalanine, which then produces the abnormal tyrosine isomers meta-tyrosine or ortho-tyrosine. While elevations in m-tyrosine and o-tyrosine concentrations have been used as a biological marker of oxidative stress, there is emerging evidence from bacterial, plant, and mammalian studies demonstrating that these isomers, particularly m-tyrosine, directly produce adverse effects to cells and tissues. These new findings suggest that the abnormal tyrosine isomers could in fact represent mediators of the effects of oxidative stress. Consequently the accumulation of m- and o-tyrosine may disrupt cellular homeostasis and contribute to disease pathogenesis, and as result, effective defenses against oxidative stress can encompass not only the elimination of reactive oxygen species but also the metabolism and ultimately the removal of the abnormal tyrosine isomers from the cellular amino acid pool. Future research in this area is needed to clarify the biologic mechanisms by which the tyrosine isomers damage cells and disrupt the function of tissues and organs and to identify the metabolic pathways involved in removing the accumulated isomers after exposure to oxidative stress.
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Affiliation(s)
- Brett R Ipson
- MD/PhD Program, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States; Department of Cell and Structural Biology, Graduate School of Biomedical Sciences, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States; Center for Healthy Aging, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States
| | - Alfred L Fisher
- Center for Healthy Aging, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States; Department of Medicine, Division of Geriatrics, Gerontology, and Palliative Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States; GRECC, South Texas VA Health Care System, San Antonio, TX, United States.
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12
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Kartvelishvili E, Peretz M, Tworowski D, Moor N, Safro M. Chimeric human mitochondrial PheRS exhibits editing activity to discriminate nonprotein amino acids. Protein Sci 2015; 25:618-26. [PMID: 26645192 DOI: 10.1002/pro.2855] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 11/10/2015] [Indexed: 11/11/2022]
Abstract
Mitochondria are considered as the primary source of reactive oxygen species (ROS) in nearly all eukaryotic cells during respiration. The harmful effects of these compounds range from direct neurotoxicity to incorporation into proteins producing aberrant molecules with multiple physiological problems. Phenylalanine exposure to ROS produces multiple oxidized isomers: tyrosine, Levodopa, ortho-Tyr, meta-Tyr (m-Tyr), and so on. Cytosolic phenylalanyl-tRNA synthetase (PheRS) exerts control over the translation accuracy, hydrolyzing misacylated products, while monomeric mitochondrial PheRS lacks the editing activity. Recently we showed that "teamwork" of cytosolic and mitochondrial PheRSs cannot prevent incorporation of m-Tyr and l-Dopa into proteins. Here, we present human mitochondrial chimeric PheRS with implanted editing module taken from EcPheRS. The monomeric mitochondrial chimera possesses editing activity, while in bacterial and cytosolic PheRSs this type of activity was detected for the (αβ)2 architecture only. The fusion protein catalyzes aminoacylation of tRNA(Phe) with cognate phenylalanine and effectively hydrolyzes the noncognate aminoacyl-tRNAs: Tyr-tRNA(Phe) and m-Tyr-tRNA(Phe) .
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Affiliation(s)
| | - Moshe Peretz
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Dmitry Tworowski
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Nina Moor
- Institute of Chemical Biology and Fundamental Medicine, Novosibirsk, 630090, Russia
| | - Mark Safro
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, 76100, Israel
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13
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Zhang S, Bartkowiak L, Nabiswa B, Mishra P, Fann J, Ouellette D, Correia I, Regier D, Liu J. Identifying low-level sequence variants via next generation sequencing to aid stable CHO cell line screening. Biotechnol Prog 2015; 31:1077-85. [DOI: 10.1002/btpr.2119] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 05/04/2015] [Indexed: 01/07/2023]
Affiliation(s)
- Sheng Zhang
- Process Sciences Cell Culture, Abbvie Bioresearch Center; 100 Research Drive Worcester MA 01605
| | - Lisa Bartkowiak
- Process Sciences Cell Culture, Abbvie Bioresearch Center; 100 Research Drive Worcester MA 01605
| | - Bernard Nabiswa
- Process Sciences Cell Culture, Abbvie Bioresearch Center; 100 Research Drive Worcester MA 01605
| | - Pratibha Mishra
- Process Sciences Cell Culture, Abbvie Bioresearch Center; 100 Research Drive Worcester MA 01605
| | - John Fann
- Process Sciences Cell Culture, Abbvie Bioresearch Center; 100 Research Drive Worcester MA 01605
| | - David Ouellette
- Process Sciences Analytics, Abbvie Bioresearch Center; 100 Research Drive Worcester MA 01605
| | - Ivan Correia
- Process Sciences Analytics, Abbvie Bioresearch Center; 100 Research Drive Worcester MA 01605
| | - Dean Regier
- Protein Science, Abbvie Bioresearch Center; 100 Research Drive Worcester MA 01605
| | - Junjian Liu
- Protein Science, Abbvie Bioresearch Center; 100 Research Drive Worcester MA 01605
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