| 1. |
- Edfors, Fredrik, et al.
(author)
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Enhanced validation of antibodies for research applications
- 2018
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In: Nature Communications. - : Nature Publishing Group. - 2041-1723. ; 9
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Journal article (peer-reviewed)abstract
- There is a need for standardized validation methods for antibody specificity and selectivity. Recently, five alternative validation pillars were proposed to explore the specificity of research antibodies using methods with no need for prior knowledge about the protein target. Here, we show that these principles can be used in a streamlined manner for enhanced validation of research antibodies in Western blot applications. More than 6,000 antibodies were validated with at least one of these strategies involving orthogonal methods, genetic knockdown, recombinant expression, independent antibodies, and capture mass spectrometry analysis. The results show a path forward for efforts to validate antibodies in an application-specific manner suitable for both providers and users.
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| 2. |
- Schwarz, Hubert, et al.
(author)
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Integrated continuous biomanufacturing on pilot scale for acid-sensitive monoclonal antibodies
- 2022
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In: Biotechnology and Bioengineering. - : Wiley. - 0006-3592 .- 1097-0290.
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Journal article (peer-reviewed)abstract
- In this study, we demonstrated the first, to our knowledge, integrated continuous bioprocess (ICB) designed for the production of acid-sensitive monoclonal antibodies, prone to aggregate at low pH, on pilot scale. A high cell density perfusion culture, stably maintained at 100 × 106 cells/ml, was integrated with the downstream process, consisting of a capture step with the recently developed Protein A ligand, ZCa; a solvent/detergent-based virus inactivation; and two ion-exchange chromatography steps. The use of a mild pH in the downstream process makes this ICB suitable for the purification of acid-sensitive monoclonal antibodies. Integration and automation of the downstream process were achieved using the Orbit software, and the same equipment and control system were used in initial small-scale trials and the pilot-scale downstream process. High recovery yields of around 90% and a productivity close to 1 g purified antibody/L/day were achieved, with a stable glycosylation pattern and efficient removal of impurities, such as host cell proteins and DNA. Finally, negligible levels of antibody aggregates were detected owing to the mild conditions used throughout the process. The present work paves the way for future industrial-scale integrated continuous biomanufacturing of all types of antibodies, regardless of acid stability.
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| 3. |
- Tegel, Hanna, et al.
(author)
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High throughput generation of a resource of the human secretome in mammalian cells
- 2020
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In: New Biotechnology. - : Elsevier BV. - 1871-6784 .- 1876-4347. ; 58, s. 45-54
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Journal article (peer-reviewed)abstract
- The proteins secreted by human tissues and blood cells, the secretome, are important both for the basic understanding of human biology and for identification of potential targets for future diagnosis and therapy. Here, a high-throughput mammalian cell factory is presented that was established to create a resource of recombinant full-length proteins covering the majority of those annotated as 'secreted' in humans. The full-length DNA sequences of each of the predicted secreted proteins were generated by gene synthesis, the constructs were transfected into Chinese hamster ovary (CHO) cells and the recombinant proteins were produced, purified and analyzed. Almost 1,300 proteins were successfully generated and proteins predicted to be secreted into the blood were produced with a success rate of 65%, while the success rates for the other categories of secreted proteins were somewhat lower giving an overall one-pass success rate of ca. 58%. The proteins were used to generate targeted proteomics assays and several of the proteins were shown to be active in a phenotypic assay involving pancreatic beta-cell dedifferentiation. Many of the proteins that failed during production in CHO cells could be rescued in human embryonic kidney (HEK 293) cells suggesting that a cell factory of human origin can be an attractive alternative for production in mammalian cells. In conclusion, a high-throughput protein production and purification system has been successfully established to create a unique resource of the human secretome.
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| 4. |
- Uhlén, Mathias, et al.
(author)
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The human secretome
- 2019
-
In: Science Signaling. - : American Association for the Advancement of Science (AAAS). - 1945-0877 .- 1937-9145. ; 12:609
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Journal article (peer-reviewed)abstract
- The proteins secreted by human cells (collectively referred to as the secretome) are important not only for the basic understanding of human biology but also for the identification of potential targets for future diagnostics and therapies. Here, we present a comprehensive analysis of proteins predicted to be secreted in human cells, which provides information about their final localization in the human body, including the proteins actively secreted to peripheral blood. The analysis suggests that a large number of the proteins of the secretome are not secreted out of the cell, but instead are retained intracellularly, whereas another large group of proteins were identified that are predicted to be retained locally at the tissue of expression and not secreted into the blood. Proteins detected in the human blood by mass spectrometry-based proteomics and antibody-based immuno-assays are also presented with estimates of their concentrations in the blood. The results are presented in an updated version 19 of the Human Protein Atlas in which each gene encoding a secretome protein is annotated to provide an open-access knowledge resource of the human secretome, including body-wide expression data, spatial localization data down to the single-cell and subcellular levels, and data about the presence of proteins that are detectable in the blood.
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| 5. |
- Hober, Andreas, et al.
(author)
-
Absolute Quantification of Apolipoproteins Following Treatment with Omega-3 Carboxylic Acids and Fenofibrate Using a High Precision Stable Isotope-labeled Recombinant Protein Fragments Based SRM Assay
- 2019
-
In: Molecular & Cellular Proteomics. - : AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC. - 1535-9476 .- 1535-9484. ; 18:12, s. 2433-2446
-
Journal article (peer-reviewed)abstract
- Stable isotope-labeled standard (SIS) peptides are used as internal standards in targeted proteomics to provide robust protein quantification, which is required in clinical settings. However, SIS peptides are typically added post trypsin digestion and, as the digestion efficiency can vary significantly between peptides within a protein, the accuracy and precision of the assay may be compromised. These drawbacks can be remedied by a new class of internal standards introduced by the Human Protein Atlas project, which are based on SIS recombinant protein fragments called SIS PrESTs. SIS PrESTs are added initially to the sample and SIS peptides are released on trypsin digestion. The SIS PrEST technology is promising for absolute quantification of protein biomarkers but has not previously been evaluated in a clinical setting. An automated and scalable solid phase extraction workflow for desalting and enrichment of plasma digests was established enabling simultaneous preparation of up to 96 samples. Robust high-precision quantification of 13 apolipoproteins was achieved using a novel multiplex SIS PrEST-based LC-SRM/MS Tier 2 assay in non-depleted human plasma. The assay exhibited inter-day coefficients of variation between 1.5% and 14.5% (median = 3.5%) and was subsequently used to investigate the effects of omega-3 carboxylic acids (OM3-CA) and fenofibrate on these 13 apolipoproteins in human plasma samples from a randomized placebo-controlled trial, EFFECT I (NCT02354976). No significant changes were observed in the OM3-CA arm, whereas treatment with fenofibrate significantly increased apoAII and reduced apoB, apoCI, apoE and apoCIV levels. The reduction in apoCIV following fenofibrate treatment is a novel finding. The study demonstrates that SIS PrESTs can facilitate the generation of robust multiplexed biomarker Tier 2 assays for absolute quantification of proteins in clinical studies. Applications of LC-SRM in clinical research are still limited. SIS PrEST are a novel class of standards added prior to trypsinization. We have developed a semi-automated sample preparation workflow and a SIS PrEST LC-SRM/MS Tier 2 assay for absolute quantification of 13 apolipoproteins in human plasma and applied it on clinical samples from the EFFECT I study. We demonstrate, for the first time, that SIS PrEST can be applied for exploratory biomarker research in clinical settings and capture drug effects.
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| 6. |
- Hober, Andreas, 1992-
(author)
-
Development of novel affinity enrichment strategies for clinical applications using selected reaction monitoring
- 2022
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Doctoral thesis (other academic/artistic)abstract
- Proteins are key components of any living organism and an essential part of life itself. They can provide cells with structure and perform life-sustaining intracellular reactions. As organisms grow more complex, this task expands even further. The proteins’ areas of responsibility suddenly also include communication and coordination between cells and throughout entire organisms, such as the human body. Everything that can be touched and felt on a living organism is composed of millions and millions of proteins tightly packed together. They are even the molecules responsible for propagating the signals that make up the sense of feeling. Understanding the role of proteins in the complex system of life is essential for understanding what makes up a healthy human and what causes disease. This knowledge makes up the foundation of modern medicine, and to further this knowledge, allowing for new treatments and preventative interventions, the study of proteins is crucial. The large-scale study of proteins, proteomics, is an extensive field of research where a vast toolbox of technologies has been implemented. The foundation for this toolbox is made up of mass spectrometry- and affinity-based technologies.In this thesis, both mass spectrometry-based proteomics and affinity-based proteomics will be explored. The first part, Paper I and Paper II, describe the use of selected reaction monitoring for measuring proteins of clinical relevance in human blood plasma. The second part, Paper III and Paper IV, highlight the importance of validating reagents used for affinity-based proteomics and how this can be achieved in a high throughput manner. Lastly, Paper V showcases how a combined strategy, relying on both affinity-based proteomics and mass spectrometry-based proteomics, can capitalize on the best properties of each technology and how this combined strategy can even be utilized for diagnostic purposes.
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| 7. |
- Hober, Andreas, 1992-, et al.
(author)
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Evaluation of an enhanced antibody-validation strategy for Western blot applications based on migration pattern recognition
-
Other publication (other academic/artistic)abstract
- The use of affinity reagents, such as antibodies, for studying specific molecules in complex backgrounds are some of the most powerful tools for researchers in molecular biology. However, all experiments performed using affinity reagents are directly affected by each reagent’s context-dependent ability to bind specifically to a target of interest. A growing issue with non-validated, or poorly validated affinity reagents, has been highlighted by the International Working Group for Antibody Validation (IWGAV). It has been suggested that antibodies should be evaluated in an application-specific manner since they can perform well in one application but fail to deliver reproducible results in another. One of the most commonly used antibody-based applications is the Western blot (WB) technology. When evaluating the result from a WB experiment, the initial measure used for determining whether or not the antibody binds the protein of interest is to determine the molecular weight of the protein detected by the antibody compared to a set of reference proteins. As WB relies on the SDS-PAGE for separating differently sized proteins, the comparison is actually based on protein migration during electrophoresis. It is, however, well known that the migration of a protein can differ significantly from how the reference proteins migrate. Here, we suggest a method for determining the actual migration patterns of proteins instead of relying on the theoretical molecular weight of the protein. Using this approach, called migration capture mass spectrometry (MS), a dataset containing the migration patterns of more than 39,000 protein products from more than 10,500 genes across eleven cell lines and tissues has been created. This migration capture MS approach has been validated using k-fold cross validation against 249 siRNA knockdown WBs showing that the method has a sensitivity of 96.4%, specificity of 87.4% and accuracy of 91.9%, which makes the dataset a useful resource that can facilitate antibody validation strategies in a fit-for-purpose manner. The data set has allowed the automatic evaluation of more than 12,000 antibodies in the Human Protein Atlas using the method.
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| 8. |
- Hober, Andreas, et al.
(author)
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Rapid and sensitive detection of SARS-CoV-2 infection using quantitative peptide enrichment LC-MS analysis
- 2021
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In: eLIFE. - : eLIFE SCIENCES PUBL LTD. - 2050-084X. ; 10
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Journal article (peer-reviewed)abstract
- Reliable, robust, large-scale molecular testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is essential for monitoring the ongoing coronavirus disease 2019 (COVID-19) pandemic. We have developed a scalable analytical approach to detect viral proteins based on peptide immuno-affinity enrichment combined with liquid chromatography-mass spectrometry (LC-MS). This is a multiplexed strategy, based on targeted proteomics analysis and read-out by LC-MS, capable of precisely quantifying and confirming the presence of SARS-CoV-2 in phosphate-buffered saline (PBS) swab media from combined throat/nasopharynx/saliva samples. The results reveal that the levels of SARS-CoV-2 measured by LC-MS correlate well with their correspondingreal-time polymerase chain reaction (RT-PCR) read-out (r = 0.79). The analytical workflow shows similar turnaround times as regular RT-PCR instrumentation with a quantitative read-out of viral proteins corresponding to cycle thresholds (Ct) equivalents ranging from 21 to 34. Using RT-PCR as a reference, we demonstrate that the LC-MS-based method has 100% negative percent agreement (estimated specificity) and 95% positive percent agreement (estimated sensitivity) when analyzing clinical samples collected from asymptomatic individuals with a Ct within the limit of detection of the mass spectrometer (Ct <= 30). These results suggest that a scalable analytical method based on LC-MS has a place in future pandemic preparedness centers to complement current virus detection technologies.
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| 9. |
- Hober, Andreas, 1992-, et al.
(author)
-
Targeted Proteomics Using Stable Isotope Labeled Protein Fragments Enables Precise and Robust Determination of Total Apolipoprotein(a) in Human Plasma
-
Other publication (other academic/artistic)abstract
- Lipoprotein(a), also known as Lp(a), is an LDL-like particle composed of apolipoprotein(a) (apo(a)) bound covalently to apolipoprotein B100. Plasma concentrations of Lp(a) are highly heritable and vary widely between individuals. Elevated plasma concentration of Lp(a) is considered as an independent, causal risk factor of cardiovascular disease (CVD). Targeted mass spectrometry (LC-SRM/MS) combined with stable isotope-labeled recombinant proteins provides robust and precise quantification of proteins in the blood, making LC-SRM/MS assays appealing for monitoring plasma proteins for clinical implications. This study presents a novel quantitative approach, based on proteotypic peptides, to determine the absolute concentration of apo(a) from two microliters of plasma and qualified according to guideline requirements for targeted proteomics assays. After optimization, assay parameters such as linearity, lower limits of quantification (LLOQ), intra-assay variability (CV: 4.7%) and inter-assay repeatability (CV: 7.8%) were determined and the LC-SRM/MS results were benchmarked against a commercially available immunoassay. In summary, the measurements of an apo(a) single copy specific peptide and a kringle 4 specific peptide allows for the determination of molar concentration and relative size of apo(a) in individuals.
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| 10. |
- Hober, Andreas, 1992-, et al.
(author)
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Targeted proteomics using stable isotope labeled protein fragments enables precise and robust determination of total apolipoprotein(a) in human plasma
- 2023
-
In: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 18:2 February
-
Journal article (peer-reviewed)abstract
- Lipoprotein(a), also known as Lp(a), is an LDL-like particle composed of apolipoprotein(a) (apo(a)) bound covalently to apolipoprotein B100. Plasma concentrations of Lp(a) are highly heritable and vary widely between individuals. Elevated plasma concentration of Lp(a) is considered as an independent, causal risk factor of cardiovascular disease (CVD). Targeted mass spectrometry (LC-SRM/MS) combined with stable isotope-labeled recombinant proteins provides robust and precise quantification of proteins in the blood, making LC-SRM/ MS assays appealing for monitoring plasma proteins for clinical implications. This study presents a novel quantitative approach, based on proteotypic peptides, to determine the absolute concentration of apo(a) from two microliters of plasma and qualified according to guideline requirements for targeted proteomics assays. After optimization, assay parameters such as linearity, lower limits of quantification (LLOQ), intra-assay variability (CV: 4.7%) and inter-assay repeatability (CV: 7.8%) were determined and the LC-SRM/MS results were benchmarked against a commercially available immunoassay. In summary, the measurements of an apo(a) single copy specific peptide and a kringle 4 specific peptide allow for the determination of molar concentration and relative size of apo(a) in individuals.
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| 11. |
- Jahn, Michael, et al.
(author)
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Protein allocation and utilization in the versatile chemolithoautotroph Cupriavidus necator
- 2021
-
In: eLIFE. - : eLIFE SCIENCES PUBL LTD. - 2050-084X. ; 10
-
Journal article (peer-reviewed)abstract
- Bacteria must balance the different needs for substrate assimilation, growth functions, and resilience in order to thrive in their environment. Of all cellular macromolecules, the bacterial proteome is by far the most important resource and its size is limited. Here, we investigated how the highly versatile 'knallgas' bacterium Cupriavidus necator reallocates protein resources when grown on different limiting substrates and with different growth rates. We determined protein quantity by mass spectrometry and estimated enzyme utilization by resource balance analysis modeling. We found that C. necator invests a large fraction of its proteome in functions that are hardly utilized. Of the enzymes that are utilized, many are present in excess abundance. One prominent example is the strong expression of CBB cycle genes such as Rubisco during growth on fructose. Modeling and mutant competition experiments suggest that CO2-reassimilation through Rubisco does not provide a fitness benefit for heterotrophic growth, but is rather an investment in readiness for autotrophy.
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| 12. |
- Johansson, Camilla, et al.
(author)
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Monitoring Biomarker Study in Becker Muscular Dystrophy using Data Independent Acquisition LC-MS/MS
-
Other publication (other academic/artistic)abstract
- Becker muscular dystrophy (BMD) is a rare and heterogenous form of dystrophinopathy caused by reduced expression of altered dystrophin protein. Gene therapies and exon-skipping therapies for the more severe form of dystrophinopathy, Duchenne muscular dystrophy (DMD), assumes that by promoting partial dystrophin expression in DMD patients, their disease progression could be reduced. Several studies have identified potential progression biomarkers for DMD and hypothesised in their usefulness in monitoring pharmacodynamic response in gene-therapy clinical trials. However, knowledge of progression changes of blood proteome in BMD is lacking. In this study, we aimed at exploring differences in proteomic changes between DMD and BMD in a prospective longitudinal 4-year study as well as explore what proteins relate to functional performance in BMD patients. Serum from 48 BMD patients and 19 DMD patients were analysed using Data Independent Acquisition Tandem Mass Spectrometry (DIA-MS). Linear mixed effects models identified 17 proteins with altered longitudinal signatures between DMD and BMD, among these CKM, PKM and ALDOA. Furthermore, bikunin (product of AMBP gene), C3 and IGHG2 were found related to functional performance in BMD patients.
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| 13. |
- Johansson, Camilla, 1993-, et al.
(author)
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Orthogonal proteomics methods warrant the development of Duchenne muscular dystrophy biomarkers
- 2023
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In: Clinical Proteomics. - : Springer Nature. - 1542-6416 .- 1559-0275. ; 20:1
-
Journal article (peer-reviewed)abstract
- BackgroundMolecular components in blood, such as proteins, are used as biomarkers to detect or predict disease states, guide clinical interventions and aid in the development of therapies. While multiplexing proteomics methods promote discovery of such biomarkers, their translation to clinical use is difficult due to the lack of substantial evidence regarding their reliability as quantifiable indicators of disease state or outcome. To overcome this challenge, a novel orthogonal strategy was developed and used to assess the reliability of biomarkers and analytically corroborate already identified serum biomarkers for Duchenne muscular dystrophy (DMD). DMD is a monogenic incurable disease characterized by progressive muscle damage that currently lacks reliable and specific disease monitoring tools.MethodsTwo technological platforms are used to detect and quantify the biomarkers in 72 longitudinally collected serum samples from DMD patients at 3 to 5 timepoints. Quantification of the biomarkers is achieved by detection of the same biomarker fragment either through interaction with validated antibodies in immuno-assays or through quantification of peptides by Parallel Reaction Monitoring Mass Spectrometry assay (PRM-MS).ResultsFive, out of ten biomarkers previously identified by affinity-based proteomics methods, were confirmed to be associated with DMD using the mass spectrometry-based method. Two biomarkers, carbonic anhydrase III and lactate dehydrogenase B, were quantified with two independent methods, sandwich immunoassays and PRM-MS, with Pearson correlations of 0.92 and 0.946 respectively. The median concentrations of CA3 and LDHB in DMD patients was elevated in comparison to those in healthy individuals by 35- and 3-fold, respectively. Levels of CA3 vary between 10.26 and 0.36 ng/ml in DMD patients whereas those of LDHB vary between 15.1 and 0.8 ng/ml.ConclusionsThese results demonstrate that orthogonal assays can be used to assess the analytical reliability of biomarker quantification assays, providing a means to facilitate the translation of biomarkers to clinical practice. This strategy also warrants the development of the most relevant biomarkers, markers that can be reliably quantified with different proteomics methods.
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| 14. |
- Kotol, David, et al.
(author)
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Absolute Quantification of Pan-Cancer Plasma Proteomes Reveals Unique Signature in Multiple Myeloma
- 2023
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In: Cancers. - : MDPI AG. - 2072-6694. ; 15:19
-
Journal article (peer-reviewed)abstract
- Mass spectrometry based on data-independent acquisition (DIA) has developed into a powerful quantitative tool with a variety of implications, including precision medicine. Combined with stable isotope recombinant protein standards, this strategy provides confident protein identification and precise quantification on an absolute scale. Here, we describe a comprehensive targeted proteomics approach to profile a pan-cancer cohort consisting of 1800 blood plasma samples representing 15 different cancer types. We successfully performed an absolute quantification of 253 proteins in multiplex. The assay had low intra-assay variability with a coefficient of variation below 20% (CV = 17.2%) for a total of 1013 peptides quantified across almost two thousand injections. This study identified a potential biomarker panel of seven protein targets for the diagnosis of multiple myeloma patients using differential expression analysis and machine learning. The combination of markers, including the complement C1 complex, JCHAIN, and CD5L, resulted in a prediction model with an AUC of 0.96 for the identification of multiple myeloma patients across various cancer patients. All these proteins are known to interact with immunoglobulins.
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| 15. |
- Kotol, David, et al.
(author)
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Longitudinal Plasma Protein Profiling Using Targeted Proteomics and Recombinant Protein Standards
- 2020
-
In: Journal of Proteome Research. - : American Chemical Society (ACS). - 1535-3893 .- 1535-3907. ; 19:12, s. 4815-4825
-
Journal article (peer-reviewed)abstract
- Spike-in of standards of known concentrations used in proteomics-based workflows is an attractive approach for both accurate and precise multiplexed protein quantification. Here, a quantitative method based on targeted proteomics analysis of plasma proteins using isotope-labeled recombinant standards originating from the Human Protein Atlas project has been established. The standards were individually quantified prior to being employed in the final multiplex assay. The assays are mainly directed toward actively secreted proteins produced in the liver, but may also originate from other parts of the human body. This study included 21 proteins classified by the FDA as either drug targets or approved clinical protein biomarkers. We describe the use of this multiplex assay for profiling a well-defined human cohort with sample collection spanning over a one-year period. Samples were collected at four different time points, which allowed for a longitudinal analysis to assess the variable plasma proteome within individuals. Two assays toward APOA1 and APOB had available clinical data, and the two assays were benchmarked against each other. The clinical assay is based on antibodies and shows high correlation between the two orthogonal methods, suggesting that targeted proteomics with highly parallel, multiplex analysis is an attractive alternative to antibody-based protein assays.
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| 16. |
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| 17. |
- Kotol, David, et al.
(author)
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Targeted proteomics analysis of plasma proteins using recombinant protein standards for addition only workflows
- 2021
-
In: BioTechniques. - : Future Science Ltd. - 0736-6205 .- 1940-9818. ; 71:3, s. 473-483
-
Journal article (peer-reviewed)abstract
- Targeted proteomics is an attractive approach for the analysis of blood proteins. Here, we describe a novel analytical platform based on isotope-labeled recombinant protein standards stored in a chaotropic agent and subsequently dried down to allow storage at ambient temperature. This enables a straightforward protocol suitable for robotic workstations. Plasma samples to be analyzed are simply added to the dried pellet followed by enzymatic treatment and mass spectrometry analysis. Here, we show that this approach can be used to precisely (coefficient of variation <10%) determine the absolute concentrations in human plasma of hundred clinically relevant protein targets, spanning four orders of magnitude, using simultaneous analysis of 292 peptides. The use of this next-generation analytical platform for high-throughput clinical proteome profiling is discussed.
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| 18. |
- Li, Xiangyu, et al.
(author)
-
Discovery of Functional Alternatively Spliced PKM Transcripts in Human Cancers
- 2021
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In: Cancers. - : MDPI AG. - 2072-6694. ; 13:2, s. 1-23
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Journal article (peer-reviewed)abstract
- Simple Summary Pyruvate kinase muscle type (PKM) is a key enzyme in glycolysis and is a mediator of the Warburg effect in tumors. The association of PKM with survival of cancer patients is controversial. In this study, we investigated the associations of the alternatively spliced transcripts of PKM with cancer patients' survival outcomes and explained the conflicts in previous studies. We discovered three poorly studied alternatively spliced PKM transcripts that exhibited opposite prognostic indications in different human cancers based on integrative systems analysis. We also detected their protein products and explored their potential biological functions based on in-vitro experiments. Our analysis demonstrated that alternatively spliced transcripts of not only PKM but also other genes should be considered in cancer studies, since it may enable the discovery and targeting of the right protein product for development of the efficient treatment strategies. Pyruvate kinase muscle type (PKM) is a key enzyme in glycolysis and plays an important oncological role in cancer. However, the association of PKM expression and the survival outcome of patients with different cancers is controversial. We employed systems biology methods to reveal prognostic value and potential biological functions of PKM transcripts in different human cancers. Protein products of transcripts were shown and detected by western blot and mass spectrometry analysis. We focused on different transcripts of PKM and investigated the associations between their mRNA expression and the clinical survival of the patients in 25 different cancers. We find that the transcripts encoding PKM2 and three previously unstudied transcripts, namely ENST00000389093, ENST00000568883, and ENST00000561609, exhibited opposite prognostic indications in different cancers. Moreover, we validated the prognostic effect of these transcripts in an independent kidney cancer cohort. Finally, we revealed that ENST00000389093 and ENST00000568883 possess pyruvate kinase enzymatic activity and may have functional roles in metabolism, cell invasion, and hypoxia response in cancer cells. Our study provided a potential explanation to the controversial prognostic indication of PKM, and could invoke future studies focusing on revealing the biological and oncological roles of these alternative spliced variants of PKM.
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| 19. |
- Löfgren, Lars, et al.
(author)
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Patient-Centric Quantitative Microsampling for Accurate Determination of Urine Albumin to Creatinine Ratio (UACR) in a Clinical Setting
- 2024
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In: The Journal of Applied Laboratory Medicine. - : Oxford University Press (OUP). - 2576-9456 .- 2475-7241. ; 9:2, s. 329-341
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Journal article (peer-reviewed)abstract
- Background: Developing and implementing new patient-centric strategies for drug trials lowers the barrier to participation for some patients by reducing the need to travel to research sites. In early chronic kidney disease (CKD) trials, albuminuria is the key measure for determining treatment effect prior to pivotal kidney outcome trials. Methods: To facilitate albuminuria sample collection outside of a clinical research site, we developed 2 quantitative microsampling methods to determine the urinary albumin to creatinine ratio (UACR). Readout was performed by LC-MS/MS. Results: For the Mitra device the within-batch precision (CV%) was 2.8% to 4.6% and the between-batch precision was 5.3% to 6.1%. Corresponding data for the Capitainer device were 4.0% to 8.6% and 6.7% to 9.0%, respectively. The storage stability at room temperature for 3 weeks was 98% to 103% for both devices. The recovery for the Mitra and Capitainer devices was 104% (SD 7.0%) and 95 (SD 7.4%), respectively. The inter-assay comparison of UACR assessment generated results that were indistinguishable regardless of microsampling technique. The accuracy based on LC-MS/MS vs analysis of neat urine using a clinical chemistry analyzer was assessed in a clinical setting, resulting in 102 ± 8.0% for the Mitra device and 95 ± 10.0% for the Capitainer device. Conclusions: Both UACR microsampling measurements exhibit excellent accuracy and precision compared to a clinical chemistry analyzer using neat urine. We applied our patient-centric sampling strategy to subjects with heart failure in a clinical setting. Precise UACR measurements using quantitative microsampling at home would be beneficial in clinical drug development for kidney therapies.
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| 20. |
- Saghaleyni, Rasool, 1987, et al.
(author)
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Enhanced metabolism and negative regulation of ER stress support higher erythropoietin production in HEK293 cells
- 2022
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In: Cell Reports. - : Elsevier BV. - 2211-1247. ; 39:11
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Journal article (peer-reviewed)abstract
- Recombinant protein production can cause severe stress on cellular metabolism, resulting in limited titer and product quality. To investigate cellular and metabolic characteristics associated with these limitations, we compare HEK293 clones producing either erythropoietin (EPO) (secretory) or GFP (non-secretory) protein at different rates. Transcriptomic and functional analyses indicate significantly higher metabolism and oxidative phosphorylation in EPO producers compared with parental and GFP cells. In addition, ribosomal genes exhibit specific expression patterns depending on the recombinant protein and the production rate. In a clone displaying a dramatically increased EPO secretion, we detect higher gene expression related to negative regulation of endoplasmic reticulum (ER) stress, including upregulation of ATF6B, which aids EPO production in a subset of clones by overexpression or small interfering RNA (siRNA) knockdown. Our results offer potential target pathways and genes for further development of the secretory power in mammalian cell factories.
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| 21. |
- Uhlén, Mathias, et al.
(author)
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A genome-wide transcriptomic analysis of protein-coding genes in human blood cells
- 2019
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In: Science. - : American Association for the Advancement of Science. - 0036-8075 .- 1095-9203. ; 366:6472, s. 1471-
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Journal article (peer-reviewed)abstract
- Blood is the predominant source for molecular analyses in humans, both in clinical and research settings. It is the target for many therapeutic strategies, emphasizing the need for comprehensive molecular maps of the cells constituting human blood. In this study, we performed a genome-wide transcriptomic analysis of protein-coding genes in sorted blood immune cell populations to characterize the expression levels of each individual gene across the blood cell types. All data are presented in an interactive, open-access Blood Atlas as part of the Human Protein Atlas and are integrated with expression profiles across all major tissues to provide spatial classification of all protein-coding genes. This allows for a genome-wide exploration of the expression profiles across human immune cell populations and all major human tissues and organs.
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| 22. |
- von Witting, Emma, et al.
(author)
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ADAPT as a single-domain bispecific scaffold capable of albumin-associated haf-life extension for therapeutic applications
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Other publication (other academic/artistic)abstract
- Albumin-binding fusion partners are frequently used as a means for the in vivo half-life extension of small therapeutic molecules that would normally be cleared very rapidly from circulation. However, in applications where small size is key, fusion to an additional molecule can be disadvantageous. ABD-Derived Affinity ProTeins (ADAPTs) are a type of scaffold proteins based on one of the albumin binding domains of streptococcal Protein G, with newly introduced binding specificities against numerous targets. Here we engineered this scaffold further and showed that this domain, as small as 6 kDa, can harbor two distinct binding surfaces and utilize them to interact with two targets simultaneously. These novel ADAPTs were developed to bind to both serum albumin as well as another clinically relevant target, thus circumventing the need for an albumin binding fusion partner. To accomplish this, we designed a novel phage display library and used it to successfully select for single-domain bispecific binders towards a panel of targets: TNFa, PSA (Prostate Specific Antigen), CRP (C-reactive protein), renin, angiogenin and insulin. Apart from successfully identifying bispecific binders for all targets, we also demonstrated the formation of the ternary complex of the ADAPT together with albumin and each of the four targets TNFa, PSA, angiogenin and insulin. This simultaneous binding of albumin and other targets presents an opportunity to combine the advantages of small molecules with those of larger ones allowing for lower cost of goods and non-invasive administration routes while still maintaining a sufficient in vivo half-life.
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| 23. |
- von Witting, Emma, et al.
(author)
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Small Bispecific Affinity Proteins for Simultaneous Target Binding and Albumin-Associated Half-Life Extension
- 2021
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In: Molecular Pharmaceutics. - : American Chemical Society (ACS). - 1543-8384 .- 1543-8392. ; 18:1, s. 328-337
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Journal article (peer-reviewed)abstract
- Albumin-binding fusion partners are frequently used as a means for the in vivo half-life extension of small therapeutic molecules that would normally be cleared very rapidly from circulation. However, in applications where small size is key, fusion to an additional molecule can be disadvantageous. Albumin-derived affinity proteins (ADAPTs) are a new type of scaffold proteins based on one of the albumin-binding domains of streptococcal protein G, with engineered binding specificities against numerous targets. Here, we engineered this scaffold further and showed that this domain, as small as 6 kDa, can harbor two distinct binding surfaces and utilize them to interact with two targets simultaneously. These novel ADAPTs were developed to possess affinity toward both serum albumin as well as another clinically relevant target, thus circumventing the need for an albumin-binding fusion partner. To accomplish this, we designed a phage display library and used it to successfully select for single-domain bispecific binders toward a panel of targets: TNFα, prostate-specific antigen (PSA), C-reactive protein (CRP), renin, angiogenin, myeloid-derived growth factor (MYDGF), and insulin. Apart from successfully identifying bispecific binders for all targets, we also demonstrated the formation of the ternary complex consisting of the ADAPT together with albumin and each of the five targets, TNFα, PSA, angiogenin, MYDGF, and insulin. This simultaneous binding of albumin and other targets presents an opportunity to combine the advantages of small molecules with those of larger ones allowing for lower cost of goods and noninvasive administration routes while still maintaining a sufficient in vivo half-life.
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