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ackground: Depression and anxiety are two of the most prevalent and disabling mental disorders worldwide, both in the general population and in outpatient clinical settings. Objective: This study aimed to analyze the psychometric properties of the Patient Health Questionnaire-4 (PHQ-4) based on network analysis metrics. Methods: A total of 911 Paraguayans (23.71% women and 76.29% men; mean age 31.25 years, SD = 10.63), selected by non-probabilistic convenience sampling, participated in the study. Network analysis was used to evaluate the internal structure, reliability, and measurement invariance between men and women. Results: The results revealed that the PHQ-4 is a unidimensional measure through Exploratory Graph Analysis (EGA). Reliability, through structural consistency, identified that 100% of the time, only a single dimension was obtained, and all items remained stable, as they were always replicated within the empirical dimension. The unidimensional structure has shown evidence of configural invariance; therefore, the network structure functioned equally among the different sex groups. Conclusion: The PHQ-4 presented optimal preliminary evidence of validity based on its internal structure, reliability, and invariance between sexes. Therefore, it may be useful as an accurate and brief measure of anxiety and depressive symptoms in the Paraguayan context., Horizon 2020 Framework Programme

Therapeutic proteins are becoming increasingly important. They are desirable, as they typically possess low adverse effects and higher specificity compared to the traditional, small molecule drugs. But they are also more complex and involve different intricate and expensive development and production processes. Through new technologies in protein and cell line development, more efficient and safer drugs can be readily available and at a lower cost. This thesis gives an overview of how protein therapeutics are developed and produced. It explores strategies to improve the efficacy and safety of protein drugs and how to improve production yields. In the present investigation, two papers present new methods for high-throughput cloning and site-directed mutagenesis using solid-phase immobilization of DNA fragments. These methods were designed to generate new drug candidates with swiftness and ease. Three papers show the development of a new cell line screening system that combines droplet microfluidics and the split-GFP reporter system. This combination allows for relative quantification of secreted recombinant proteins between individual cells and provides a tool for the selection of the best-producing clones for final production from a heterologous cell pool. The final paper explores the possibility to produce proteins at a higher cell density by examining how the metabolome and proteome of a perfusion bioreactor evolve as the cell density reaches exceptionally high levels. The consistent goal of all of these studies is to expedite the development and improve the production of therapeutic proteins, to assist the discovery of new drugs and to bring down production and development costs. Engineered proteins can be used to cure previously incurable diseases or give current medications a higher efficacy. Lower production and development costs can make the treatments available to more people., QC 20180507

Therapeutic proteins are becoming increasingly important. They are desirable, as they typically possess low adverse effects and higher specificity compared to the traditional, small molecule drugs. But they are also more complex and involve different intricate and expensive development and production processes. Through new technologies in protein and cell line development, more efficient and safer drugs can be readily available and at a lower cost. This thesis gives an overview of how protein therapeutics are developed and produced. It explores strategies to improve the efficacy and safety of protein drugs and how to improve production yields. In the present investigation, two papers present new methods for high-throughput cloning and site-directed mutagenesis using solid-phase immobilization of DNA fragments. These methods were designed to generate new drug candidates with swiftness and ease. Three papers show the development of a new cell line screening system that combines droplet microfluidics and the split-GFP reporter system. This combination allows for relative quantification of secreted recombinant proteins between individual cells and provides a tool for the selection of the best-producing clones for final production from a heterologous cell pool. The final paper explores the possibility to produce proteins at a higher cell density by examining how the metabolome and proteome of a perfusion bioreactor evolve as the cell density reaches exceptionally high levels. The consistent goal of all of these studies is to expedite the development and improve the production of therapeutic proteins, to assist the discovery of new drugs and to bring down production and development costs. Engineered proteins can be used to cure previously incurable diseases or give current medications a higher efficacy. Lower production and development costs can make the treatments available to more people., QC 20180507

Therapeutic proteins are becoming increasingly important. They are desirable, as they typically possess low adverse effects and higher specificity compared to the traditional, small molecule drugs. But they are also more complex and involve different intricate and expensive development and production processes. Through new technologies in protein and cell line development, more efficient and safer drugs can be readily available and at a lower cost. This thesis gives an overview of how protein therapeutics are developed and produced. It explores strategies to improve the efficacy and safety of protein drugs and how to improve production yields. In the present investigation, two papers present new methods for high-throughput cloning and site-directed mutagenesis using solid-phase immobilization of DNA fragments. These methods were designed to generate new drug candidates with swiftness and ease. Three papers show the development of a new cell line screening system that combines droplet microfluidics and the split-GFP reporter system. This combination allows for relative quantification of secreted recombinant proteins between individual cells and provides a tool for the selection of the best-producing clones for final production from a heterologous cell pool. The final paper explores the possibility to produce proteins at a higher cell density by examining how the metabolome and proteome of a perfusion bioreactor evolve as the cell density reaches exceptionally high levels. The consistent goal of all of these studies is to expedite the development and improve the production of therapeutic proteins, to assist the discovery of new drugs and to bring down production and development costs. Engineered proteins can be used to cure previously incurable diseases or give current medications a higher efficacy. Lower production and development costs can make the treatments available to more people., QC 20180507

Therapeutic proteins are becoming increasingly important. They are desirable, as they typically possess low adverse effects and higher specificity compared to the traditional, small molecule drugs. But they are also more complex and involve different intricate and expensive development and production processes. Through new technologies in protein and cell line development, more efficient and safer drugs can be readily available and at a lower cost. This thesis gives an overview of how protein therapeutics are developed and produced. It explores strategies to improve the efficacy and safety of protein drugs and how to improve production yields. In the present investigation, two papers present new methods for high-throughput cloning and site-directed mutagenesis using solid-phase immobilization of DNA fragments. These methods were designed to generate new drug candidates with swiftness and ease. Three papers show the development of a new cell line screening system that combines droplet microfluidics and the split-GFP reporter system. This combination allows for relative quantification of secreted recombinant proteins between individual cells and provides a tool for the selection of the best-producing clones for final production from a heterologous cell pool. The final paper explores the possibility to produce proteins at a higher cell density by examining how the metabolome and proteome of a perfusion bioreactor evolve as the cell density reaches exceptionally high levels. The consistent goal of all of these studies is to expedite the development and improve the production of therapeutic proteins, to assist the discovery of new drugs and to bring down production and development costs. Engineered proteins can be used to cure previously incurable diseases or give current medications a higher efficacy. Lower production and development costs can make the treatments available to more people., QC 20180507

Therapeutic proteins are becoming increasingly important. They are desirable, as they typically possess low adverse effects and higher specificity compared to the traditional, small molecule drugs. But they are also more complex and involve different intricate and expensive development and production processes. Through new technologies in protein and cell line development, more efficient and safer drugs can be readily available and at a lower cost. This thesis gives an overview of how protein therapeutics are developed and produced. It explores strategies to improve the efficacy and safety of protein drugs and how to improve production yields. In the present investigation, two papers present new methods for high-throughput cloning and site-directed mutagenesis using solid-phase immobilization of DNA fragments. These methods were designed to generate new drug candidates with swiftness and ease. Three papers show the development of a new cell line screening system that combines droplet microfluidics and the split-GFP reporter system. This combination allows for relative quantification of secreted recombinant proteins between individual cells and provides a tool for the selection of the best-producing clones for final production from a heterologous cell pool. The final paper explores the possibility to produce proteins at a higher cell density by examining how the metabolome and proteome of a perfusion bioreactor evolve as the cell density reaches exceptionally high levels. The consistent goal of all of these studies is to expedite the development and improve the production of therapeutic proteins, to assist the discovery of new drugs and to bring down production and development costs. Engineered proteins can be used to cure previously incurable diseases or give current medications a higher efficacy. Lower production and development costs can make the treatments available to more people., QC 20180507

Our increasing understanding of disease mechanisms coupled with technological advances has facilitated the generation of pharmaceutical proteins, which are able to address yet unmet medical needs. Diseases that were fatal in the past can now be treated with novel biological medications improving and prolonging life for many patients. Pharmaceutical protein production is, however, a complex undertaking, which is by no means problem-free. The demand for more complex proteins and the realization of the importance of post-translational modifications have led to an increasing use of mammalian cells for protein expression. Despite improvements in design and production, the costs required for the development of pharmaceutical proteins still are far greater than those for conventional, small molecule drugs. To render such treatments affordable for healthcare suppliers and assist in the implementation of precision medicine, further progress is needed. In five papers this thesis describes strategies and methods that can help to advance the development and manufacturing of pharmaceutical proteins. Two platforms for antibody engineering have been developed and evaluated, one of which allows for efficient screening of antibody libraries whilst the second enables the straightforward generation of bispecific antibodies. Moreover, a method for epitope mapping has been devised and applied to map the therapeutic antibody eculizumab’s epitope on its target protein. In a second step it was shown how this epitope information can be used to stratify patients and, thus, contribute to the realization of precision medicine. The fourth project focuses on the cell line development process during pharmaceutical protein production. A platform is described combining split-GFP and fluorescence-activated droplet sorting, which allows for the efficient selection of highly secreting cells from a heterogeneous cell pool. In an accompanying study, the split-GFP probe was improved to enable shorter ass, QC 20170828

Our increasing understanding of disease mechanisms coupled with technological advances has facilitated the generation of pharmaceutical proteins, which are able to address yet unmet medical needs. Diseases that were fatal in the past can now be treated with novel biological medications improving and prolonging life for many patients. Pharmaceutical protein production is, however, a complex undertaking, which is by no means problem-free. The demand for more complex proteins and the realization of the importance of post-translational modifications have led to an increasing use of mammalian cells for protein expression. Despite improvements in design and production, the costs required for the development of pharmaceutical proteins still are far greater than those for conventional, small molecule drugs. To render such treatments affordable for healthcare suppliers and assist in the implementation of precision medicine, further progress is needed. In five papers this thesis describes strategies and methods that can help to advance the development and manufacturing of pharmaceutical proteins. Two platforms for antibody engineering have been developed and evaluated, one of which allows for efficient screening of antibody libraries whilst the second enables the straightforward generation of bispecific antibodies. Moreover, a method for epitope mapping has been devised and applied to map the therapeutic antibody eculizumab’s epitope on its target protein. In a second step it was shown how this epitope information can be used to stratify patients and, thus, contribute to the realization of precision medicine. The fourth project focuses on the cell line development process during pharmaceutical protein production. A platform is described combining split-GFP and fluorescence-activated droplet sorting, which allows for the efficient selection of highly secreting cells from a heterogeneous cell pool. In an accompanying study, the split-GFP probe was improved to enable shorter ass, QC 20170828

Our increasing understanding of disease mechanisms coupled with technological advances has facilitated the generation of pharmaceutical proteins, which are able to address yet unmet medical needs. Diseases that were fatal in the past can now be treated with novel biological medications improving and prolonging life for many patients. Pharmaceutical protein production is, however, a complex undertaking, which is by no means problem-free. The demand for more complex proteins and the realization of the importance of post-translational modifications have led to an increasing use of mammalian cells for protein expression. Despite improvements in design and production, the costs required for the development of pharmaceutical proteins still are far greater than those for conventional, small molecule drugs. To render such treatments affordable for healthcare suppliers and assist in the implementation of precision medicine, further progress is needed. In five papers this thesis describes strategies and methods that can help to advance the development and manufacturing of pharmaceutical proteins. Two platforms for antibody engineering have been developed and evaluated, one of which allows for efficient screening of antibody libraries whilst the second enables the straightforward generation of bispecific antibodies. Moreover, a method for epitope mapping has been devised and applied to map the therapeutic antibody eculizumab’s epitope on its target protein. In a second step it was shown how this epitope information can be used to stratify patients and, thus, contribute to the realization of precision medicine. The fourth project focuses on the cell line development process during pharmaceutical protein production. A platform is described combining split-GFP and fluorescence-activated droplet sorting, which allows for the efficient selection of highly secreting cells from a heterogeneous cell pool. In an accompanying study, the split-GFP probe was improved to enable shorter ass, QC 20170828

Our increasing understanding of disease mechanisms coupled with technological advances has facilitated the generation of pharmaceutical proteins, which are able to address yet unmet medical needs. Diseases that were fatal in the past can now be treated with novel biological medications improving and prolonging life for many patients. Pharmaceutical protein production is, however, a complex undertaking, which is by no means problem-free. The demand for more complex proteins and the realization of the importance of post-translational modifications have led to an increasing use of mammalian cells for protein expression. Despite improvements in design and production, the costs required for the development of pharmaceutical proteins still are far greater than those for conventional, small molecule drugs. To render such treatments affordable for healthcare suppliers and assist in the implementation of precision medicine, further progress is needed. In five papers this thesis describes strategies and methods that can help to advance the development and manufacturing of pharmaceutical proteins. Two platforms for antibody engineering have been developed and evaluated, one of which allows for efficient screening of antibody libraries whilst the second enables the straightforward generation of bispecific antibodies. Moreover, a method for epitope mapping has been devised and applied to map the therapeutic antibody eculizumab’s epitope on its target protein. In a second step it was shown how this epitope information can be used to stratify patients and, thus, contribute to the realization of precision medicine. The fourth project focuses on the cell line development process during pharmaceutical protein production. A platform is described combining split-GFP and fluorescence-activated droplet sorting, which allows for the efficient selection of highly secreting cells from a heterogeneous cell pool. In an accompanying study, the split-GFP probe was improved to enable shorter ass, QC 20170828

Our increasing understanding of disease mechanisms coupled with technological advances has facilitated the generation of pharmaceutical proteins, which are able to address yet unmet medical needs. Diseases that were fatal in the past can now be treated with novel biological medications improving and prolonging life for many patients. Pharmaceutical protein production is, however, a complex undertaking, which is by no means problem-free. The demand for more complex proteins and the realization of the importance of post-translational modifications have led to an increasing use of mammalian cells for protein expression. Despite improvements in design and production, the costs required for the development of pharmaceutical proteins still are far greater than those for conventional, small molecule drugs. To render such treatments affordable for healthcare suppliers and assist in the implementation of precision medicine, further progress is needed. In five papers this thesis describes strategies and methods that can help to advance the development and manufacturing of pharmaceutical proteins. Two platforms for antibody engineering have been developed and evaluated, one of which allows for efficient screening of antibody libraries whilst the second enables the straightforward generation of bispecific antibodies. Moreover, a method for epitope mapping has been devised and applied to map the therapeutic antibody eculizumab’s epitope on its target protein. In a second step it was shown how this epitope information can be used to stratify patients and, thus, contribute to the realization of precision medicine. The fourth project focuses on the cell line development process during pharmaceutical protein production. A platform is described combining split-GFP and fluorescence-activated droplet sorting, which allows for the efficient selection of highly secreting cells from a heterogeneous cell pool. In an accompanying study, the split-GFP probe was improved to enable shorter ass, QC 20170828

The genomes of diverse organisms are predicted to contain 20 – 30% membrane protein encoding genes and more than half of all therapeutics target membrane proteins. However, only 2% of crystal structures deposited in the protein data bank represent integral membrane proteins. This reflects the difficulties in studying them using standard biochemical and crystallographic methods. The first problem frequently encountered when investigating membrane proteins is their low natural abundance, which is insufficient for biochemical and structural studies. The aim of my thesis was to provide a simple method to improve the production of recombinant proteins. One of the most commonly used methods to increase protein yields is codon optimization of the entire coding sequence. However, our data show that subtle synonymous codon substitutions in the 5’ region can be more efficient. This is consistent with the view that protein yields under normal conditions are more dependent on translation initiation than elongation. mRNA secondary structures around the 5’ region are in large part responsible for this effect although rare codons, as well as other factors, also contribute. We developed a PCR based method to optimize the 5’ region for increased protein production in Escherichia coli. For those proteins produced in sufficient quantities several additional hurdles remain before high quality crystals can be obtained. A second aim of my thesis work was to provide a simple method for topology mapping membrane proteins. A topology map provides information about the orientation of transmembrane regions and the location of protein domains in relation to the membrane, which can give information on structure-function relationships. To this end we explored the split-GFP system in which GFP is split between the 10th and 11th β-strands. This results in one large and one small fragment, both of which are non-fluorescent but can re-anneal and regain fluorescence if localized to the same cellular, At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 2: Manuscript.

The genomes of diverse organisms are predicted to contain 20 – 30% membrane protein encoding genes and more than half of all therapeutics target membrane proteins. However, only 2% of crystal structures deposited in the protein data bank represent integral membrane proteins. This reflects the difficulties in studying them using standard biochemical and crystallographic methods. The first problem frequently encountered when investigating membrane proteins is their low natural abundance, which is insufficient for biochemical and structural studies. The aim of my thesis was to provide a simple method to improve the production of recombinant proteins. One of the most commonly used methods to increase protein yields is codon optimization of the entire coding sequence. However, our data show that subtle synonymous codon substitutions in the 5’ region can be more efficient. This is consistent with the view that protein yields under normal conditions are more dependent on translation initiation than elongation. mRNA secondary structures around the 5’ region are in large part responsible for this effect although rare codons, as well as other factors, also contribute. We developed a PCR based method to optimize the 5’ region for increased protein production in Escherichia coli. For those proteins produced in sufficient quantities several additional hurdles remain before high quality crystals can be obtained. A second aim of my thesis work was to provide a simple method for topology mapping membrane proteins. A topology map provides information about the orientation of transmembrane regions and the location of protein domains in relation to the membrane, which can give information on structure-function relationships. To this end we explored the split-GFP system in which GFP is split between the 10th and 11th β-strands. This results in one large and one small fragment, both of which are non-fluorescent but can re-anneal and regain fluorescence if localized to the same cellular, At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 2: Manuscript.

The genomes of diverse organisms are predicted to contain 20 – 30% membrane protein encoding genes and more than half of all therapeutics target membrane proteins. However, only 2% of crystal structures deposited in the protein data bank represent integral membrane proteins. This reflects the difficulties in studying them using standard biochemical and crystallographic methods. The first problem frequently encountered when investigating membrane proteins is their low natural abundance, which is insufficient for biochemical and structural studies. The aim of my thesis was to provide a simple method to improve the production of recombinant proteins. One of the most commonly used methods to increase protein yields is codon optimization of the entire coding sequence. However, our data show that subtle synonymous codon substitutions in the 5’ region can be more efficient. This is consistent with the view that protein yields under normal conditions are more dependent on translation initiation than elongation. mRNA secondary structures around the 5’ region are in large part responsible for this effect although rare codons, as well as other factors, also contribute. We developed a PCR based method to optimize the 5’ region for increased protein production in Escherichia coli. For those proteins produced in sufficient quantities several additional hurdles remain before high quality crystals can be obtained. A second aim of my thesis work was to provide a simple method for topology mapping membrane proteins. A topology map provides information about the orientation of transmembrane regions and the location of protein domains in relation to the membrane, which can give information on structure-function relationships. To this end we explored the split-GFP system in which GFP is split between the 10th and 11th β-strands. This results in one large and one small fragment, both of which are non-fluorescent but can re-anneal and regain fluorescence if localized to the same cellular, At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 2: Manuscript.

A topology map of a membrane protein defines the location of transmembrane helices and the orientation of soluble domains relative to the membrane. In the absence of a high-resolution structure, a topology map is an essential guide for studying structurefunction relationships. Although these maps can be predicted directly from amino acid sequence, the predictions are more accurate if combined with experimental data, which are usually obtained by fusing a reporter protein to the C-terminus of the protein. However, as reporter proteins are large, they cannot be used to report on the cytoplasmic/periplasmic location of the N-terminus of a protein. Here, we show that the bimolecular split-green fluorescent protein complementation system can overcome this limitation and can be used to determine the location of both the N- and C-termini of inner membrane proteins in Escherichia coli., AuthorCount:6

Proteins are complex structures and years of research have been spent on attempts to understand their complexity. The non-covalent interactions involved in protein folding are: hydrophobic effect, electrostatic interactions, van der Waals interactions and hydrogen bonding. It has been of great interest to address the importance of each of those interactions in proteins. While hydrophobic effect is believed to play the major role in protein folding, Coulombic interactions are of importance in for example protein function, specificity, kinetics and avoidance of unspecific association. Proteins, which are usually folded under native conditions, may also enter other conformations, for example amyloid structures, upon changes in the intrinsic and extrinsic factors. The general objective of this thesis was to study the interplay of the non-covalent interactions in protein folding, assembly and aggregation processes. We found a correlation between stability and assembly of mutants of monellin which implies that the same non-covalent interactions govern the two processes. We also found that the net charge of monellin is important in order to bind to its receptor. In order to stabilize the protein PGB1, we used the split GFP method and selected mutants with elevated melting temperatures by as much as 12˚C. Another series of monellin mutants revealed a correlation between stability and aggregation lag time. In the same study a correlation between predicted aggregation propensity and aggregation lag time was found. We also investigated how terminal extensions of the amino acid sequence affected the aggregation properties of Alzheimer´s β-peptide (Aβ) and found that addition of non-aggregating sequence decreases the aggregation rate of this peptide.

Protein structure and stability are inherent in the amino acid sequence and governed by non-covalent interactions. The cooperation between forces is, however, perplexing and not well understood. In order to elucidate and predict protein folding and stability, detailed studies of non-covalent interactions are required. Presented in this thesis are detailed studies on electrostatic interactions in proteins and their contribution to protein stability for PGB1, the protein G B1 domain from Streptococcus sp. Electrostatic interactions were investigated both by means of thermal and chemical denaturation at various pH and salt concentrations using CD spectroscopy and differential scanning calorimetry, and by site-specific pKa-value determination using heteronuclear NMR spectroscopy. Investigations of electrostatic interactions both in the folded and unfolded states of the protein were conducted. The results show strong electrostatic coupling between charges in the native protein that was not efficiently screened by salt. In the unfolded state most charge-charge interactions were reduced. Novel methods in analyzing NMR titration data are introduced and used to reveal electrostatic coupling. Moreover, the relative contribution of pKa-shift arising from direct Coulomb interactions, hydrogen bonding and desolvation was elucidated. Using experimentally determined pKa-values of the folded and unfolded states the pH dependent stability could be accurately calculated and compared to denaturation studies. This thesis moreover contains results from research aiming at stabilizing proteins. The same non-covalent interactions govern the stability of an intact protein chain and the affinity between fragments of the chain, which is made use of in the novel method. Reconstituting fragments of a protein were cloned into a split-GFP system where assembly of fused fragments was visualized by green fluorescence. It was shown that the fluorescence intensity correlated to the affinity between f