ברצוננו להודות לקרן קנדית עבור חדשנות, פיתוח קולומביה הבריטית קרן ידע, לבין המכון הקנדי לבריאות מחקר (CIHR) לתמיכה בעבודה זו. MT נתמך על ידי מענק ממרכז טולה היסוד במימון עבור גיוון התפתחות חיידקים (CMDE).

<ol>
	<li>Cereghino, G. P., Cregg, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Applications+of+yeast+in+biotechnology:+protein+production+and+genetic+analysis.">Applications of yeast in biotechnology: protein production and genetic analysis.</a> Curr Opin Biotechnol. 10, 422-427 (1999).</li><li>Cregg, J. M., Barringer, K. J., Hessler, A. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pichia+pastoris+as+a+Host+System+for+Transformations.">Pichia pastoris as a Host System for Transformations.</a> Mol. Cell. Biol. 5, 3376-3385 (1985).</li><li>Cregg, J. M., Cereghino, J. L., Shi, J., Higgins, D. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recombinant+protein+expression+in+Pichia+pastoris.">Recombinant protein expression in Pichia pastoris.</a> Mol Biotechnol. 16, 23-52 (2000).</li><li>Cereghino, G. P., Cereghino, J. L., Ilgen, C., Cregg, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Production+of+recombinant+proteins+in+fermenter+cultures+of+the+yeast+Pichia+pastoris.">Production of recombinant proteins in fermenter cultures of the yeast Pichia pastoris.</a> Curr Opin Biotechnol. 4, 329-332 (2002).</li></ol>

ביטוי חלבון באמצעות pastoris methylotrophic Pichia שמרים כמערכת המארחת מתואר בפרוטוקול זה. חלבון יכול להיות מופרש לתוך המדיום בהתאם וקטור שיבוט בשימוש. הפרשת חלבון רקומביננטי הופך את טיהור הבאים קל. עם זאת, התנאים המוצג יכול להיות מותאם במיוחד הביטוי של חלבונים שונים ושינויים בתנאים פעמים הביטוי עלול לגרום רמות חלבון מוגברת. וקטור להשתמש בפרוטוקול זה יש את התכונה של epitope c-myc ו נוגדן לכך epitope ניתן לרכוש. זה מאפשר ניתוח של חלבונים אשר יש נוגדנים לא זמין עדיין. התכונה התג שלו וקטור של ההורה מאפשר טיהור חלבון על שרף מתכת chelating ויש גם נוגדן עבור המקטע תג שלו של וקטור זמין. כפי שמתואר בפרוטוקול זה, ביטוי החלבון pastoris Pichia הוא רב שלבי, תהליך אשר צריך להיות מתוכנן היטב ומוכן. זמן של שבועיים עד שלושה שבועות נדרש לבצע את כל השלבים אך למעט שיבוט של לבנות את עם הגן של עניין. הבסיס לשינוי מוצלח תוך פ pastoris גבוה יעיל שינוי המוסמכת שמרים תאים מבנה לינארית אשר יכול להשתלב בגנום שמרים. ניתוח המערבי כתם וטיהור שלו תג הם יישומים כדי לקבוע את רמת הביטוי של חלבון רקומביננטי הם השלבים הבאים יש לבצע לאחר פרוטוקול זה.

expression of recombinant proteins in the methylotrophic yeast pichia pastoris

ביטוי החלבון על pastoris Pichia חיידקים אוקריוטים לארח מציעה את האפשרות לייצר כמויות גדולות של חלבון רקומביננטי במערכת ביטוי מהירה וקלה לשימוש. בתור מיקרואורגניזם חד תאיים P. pastoris קל לתפעל גדל במהירות על מדיה זולה בצפיפויות גבוהות התא. להיות eukaryote, פ pastoris הוא מסוגל לבצע רבים שלאחר translational שינויים שבוצעו על ידי התאים האיקריוטים גבוהה את החלבונים רקומביננטי שהושגו לעבור קיפול חלבונים, עיבוד פרוטאוליטי, היווצרות קשר דיסולפיד glycosylation ו [1]. כפי שמרים פ methylotrophic pastoris מסוגל חילוף חומרים מתנול כמקור פחמן הבלעדי. האמרגן חזק מונואמין אלכוהול, AOX1, מוסדר בחוזקה המושרה על ידי מתנול הוא משמש הביטוי של הגן של עניין. לפיכך, הביטוי של חלבון זר יכול להיגרם על ידי הוספת מתנול עד בינוני הצמיחה [2, 3]. יתרון חשוב נוסף הוא הפרשת חלבון רקומביננטי לתוך מדיום גידול, תוך שימוש ברצף אות למקד את החלבון זרים מסלול הפרשה של pastoris פ. רק עם רמות נמוכות של חלבון אנדוגני המופרש לתקשורת על ידי שמרים עצמו ולא חלבונים להוסיף התקשורת, חלבון Heterologous בונה את רוב החלבון הכולל במדיום ומקל על הצעדים הבאים טיהור חלבון [3, 4]. וקטור משמש כאן (pPICZαA) מכיל את מקדם AOX1 לביטוי מוסדר היטב מתנול-Induced, של הגן של ריבית; האות α-factor עבור הפרשת הפרשת חלבון רקומביננטי, גן עמידות Zeocin לבחירה בשני E. coli ו Pichia ו פפטיד C-מסוף המכיל את c-myc epitope ו (6xHis) polyhistidine תג זיהוי וטיהור של חלבון רקומביננטי. אנחנו גם מראים ניתוח כתם המערבי של חלבון רקומביננטי באמצעות נוגדנים ספציפיים נגד myc-HRP הכרה epitope c-myc על וקטור האב.

Watch this Scientific Journal Video about Expression of Recombinant Proteins in the Methylotrophic Yeast Pichia pastoris at JoVE.com

Expression of Recombinant Proteins in the Methylotrophic Yeast Pichia pastoris

הפרוטוקול מתאר ביטוי חלבון באמצעות שמרים methylotrophic<em&gt; Pichia pastoris</em&gt;. הכנת תאים שמרים electrocompetent, טרנספורמציה של וקטור עם הגן של עניין אל<em&gt; פ &#39; pastoris</em&gt; ו-DNA טיהור שמרים מבוצעות גם. ניתוח המערבי כתם וטיהור חלבונים בונים את הצעדים האחרונים בפרוטוקול זה ביטוי חלבון.

ביטוי של חלבונים רקומביננטי השמרים Methylotrophic Pichia pastoris</em

Protein expression in the microbial eukaryotic host Pichia pastoris offers the possibility to generate high amounts of recombinant protein in a fast and ...

expression-recombinant-proteins-methylotrophic-yeast-pichia

Nanyang Technological University

Research

JoVE Journal

Biology

Expression of Recombinant Proteins in the Methylotrophic Yeast Pichia pastoris

45.9K Views.  University of British Columbia - UBC. הפרוטוקול מתאר ביטוי חלבון באמצעות שמרים methylotrophic Pichia pastoris. הכנת תאים שמרים electrocompetent, טרנספורמציה של וקטור עם הגן של עניין אל פ ' pastoris ו-DNA טיהור שמרים מבוצעות גם. ניתוח המערבי כתם וטיהור חלבונים בונים את הצעדים האחרונים בפרוטוקול זה ביטוי חלבון....

Video: Expression of Recombinant Proteins in the Methylotrophic Yeast Pichia pastoris

Staining of Proteins in Gels with Coomassie G-250 without Organic Solvent and Acetic Acid

In classical protein staining protocols using Coomassie Brilliant Blue (CBB), solutions with high contents of toxic and flammable organic solvents (Methanol, Ethanol or 2-Propanol) and acetic acid are used for fixation, staining and destaining of proteins in a gel after SDS-PAGE. To speed up the procedure, heating the staining solution in the microwave oven for a short time is frequently used. This usually results in evaporation of toxic or hazardous Methanol, Ethanol or 2-Propanol and a strong smell of acetic acid in the lab which should be avoided due to safety considerations. In a protocol originally published in two patent applications by E.M. Wondrak (US2001046709 (A1), US6319720 (B1)), an alternative composition of the staining solution is described in which no organic solvent or acid is used. The CBB is dissolved in bidistilled water (60-80mg of CBB G-250 per liter) and 35 mM HCl is added as the only other compound in the staining solution. The CBB staning of the gel is done after SDS-PAGE and thorough washing of the gel in bidistilled water. By heating the gel during the washing and staining steps, the process can be finished faster and no toxic or hazardous compunds are evaporating. The staining of proteins occurs already within 1 minute after heating the gel in staining solution and is fully developed after 15-30 min with a slightly blue background that is destained completely by prolonged washing of the stained gel in bidistilled water, without affecting the stained protein bands.

A short protocol for protein staining with Coomassie Brilliant Blue (CBB) G-250 in polyacrylamide gels is described without using organic solvents or acetic acid as in the classical staining procedures with CBB.

הכתמה של חלבונים עם ג&#39;ל Coomassie G-250 ללא חומצה אצטית ממס אורגני

In classical protein staining protocols using Coomassie Brilliant Blue (CBB), solutions with high contents of toxic and flammable organic solvents ...

Identification of Growth Inhibition Phenotypes Induced by Expression of Bacterial Type III Effectors in Yeast

Many Gram-negative pathogenic bacteria use a type III secretion system to translocate a suite of effector proteins into the cytosol of host cells. Within the cell, type III effectors subvert host cellular processes to suppress immune responses and promote pathogen growth. Numerous type III effectors of plant and animal bacterial pathogens have been identified to date, yet only a few of them are well characterized. Understanding the functions of these effectors has been undermined by a combination of functional redundancy in the effector repertoire of a given bacterial strain, the subtle effects that they may exert to increase virulence, roles that are possibly specific to certain infection stages, and difficulties in genetically manipulating certain pathogens. Expression of type III effectors in the budding yeast Saccharomyces cerevisiae may allow circumventing these limitations and aid to the functional characterization of effector proteins. Because type III effectors often target cellular processes that are conserved between yeast and other eukaryotes, their expression in yeast may result in growth inhibition phenotypes that can be exploited to elucidate effector functions and targets. Additional advantages to using yeast for functional studies of bacterial effectors include their genetic tractability, information on predicted functions of the vast majority of their ORFs, and availability of numerous tools and resources for both genome-wide and small-scale experiments. Here we discuss critical factors for designing a yeast system for the expression of bacterial type III effector proteins. These include an appropriate promoter for driving expression of the effector gene(s) of interest, the copy number of the effector gene, the epitope tag used to verify protein expression, and the yeast strain. We present procedures to induce expression of effectors in yeast and to verify their expression by immunoblotting. In addition, we describe a spotting assay on agar plates for the identification of effector-induced growth inhibition phenotypes. The use of this protocol may be extended to the study of pathogenicity factors delivered into the host cell by any pathogen and translocation mechanism.

In this video, we describe a procedure for the expression of bacterial type III effectors in yeast and the identification of effector-induced growth inhibition phenotypes. Such phenotypes can be subsequently exploited to elucidate effector functions and targets.

זיהוי של פנוטיפים עיכוב גדילה מושרה על ידי הבעת effectors סוג חיידקית השלישי שמרים

Many Gram-negative pathogenic bacteria use a type III secretion system to translocate a suite of effector proteins into the cytosol of host cells. Within ...

In vitro Reconstitution of the Active T. castaneum Telomerase

Efforts to isolate the catalytic subunit of telomerase, TERT, in sufficient quantities for structural studies, have been met with limited success for more than a decade. Here, we present methods for the isolation of the recombinant Tribolium castaneum TERT (TcTERT) and the reconstitution of the active T. castaneum telomerase ribonucleoprotein (RNP) complex in vitro.
Telomerase is a specialized reverse transcriptase1 that adds short DNA repeats, called telomeres, to the 3' end of linear chromosomes2 that serve to protect them from end-to-end fusion and degradation. Following DNA replication, a short segment is lost at the end of the chromosome3 and without telomerase, cells continue dividing until eventually reaching their Hayflick Limit4. Additionally, telomerase is dormant in most somatic cells5 in adults, but is active in cancer cells6 where it promotes cell immortality7.
The minimal telomerase enzyme consists of two core components: the protein subunit (TERT), which comprises the catalytic subunit of the enzyme and an integral RNA component (TER), which contains the template TERT uses to synthesize telomeres8,9. Prior to 2008, only structures for individual telomerase domains had been solved10,11. A major breakthrough in this field came from the determination of the crystal structure of the active12, catalytic subunit of T. castaneum telomerase, TcTERT1.
Here, we present methods for producing large quantities of the active, soluble TcTERT for structural and biochemical studies, and the reconstitution of the telomerase RNP complex in vitro for telomerase activity assays. An overview of the experimental methods used is shown in Figure 1.

In vitro Reconstitution of the Active T. castaneum Telomerase

Efforts to isolate the catalytic subunit of telomerase, TERT, in sufficient quantities for structural studies, have been met with limited success for more than a decade. Here, we present methods for the isolation of the recombinant Tribolium castaneum TERT (TcTERT) and the reconstitution of the active T. castaneum telomerase ribonucleoprotein (RNP) complex in vitro.

ב הכינון במבחנה של ט פעילים castaneum שהטלומרז

Efforts to isolate the catalytic subunit of telomerase, TERT, in sufficient quantities for structural studies, have been met with limited success for more ...

High-throughput Purification of Affinity-tagged Recombinant Proteins

X-ray crystallography is the method of choice for obtaining a detailed view of the structure of proteins. Such studies need to be complemented by further biochemical analyses to obtain detailed insights into structure/function relationships. Advances in oligonucleotide- and gene synthesis technology make large-scale mutagenesis strategies increasingly feasible, including the substitution of target residues by all 19 other amino acids. Gain- or loss-of-function phenotypes then allow systematic conclusions to be drawn, such as the contribution of particular residues to catalytic activity, protein stability and/or protein-protein interaction specificity.
In order to attribute the different phenotypes to the nature of the mutation - rather than to fluctuating experimental conditions - it is vital to purify and analyse the proteins in a controlled and reproducible manner. High-throughput strategies and the automation of manual protocols on robotic liquid-handling platforms have created opportunities to perform such complex molecular biological procedures with little human intervention and minimal error rates1-5.
Here, we present a general method for the purification of His-tagged recombinant proteins in a high-throughput manner. In a recent study, we applied this method to a detailed structure-function investigation of TFIIB, a component of the basal transcription machinery. TFIIB is indispensable for promoter-directed transcription in vitro and is essential for the recruitment of RNA polymerase into a preinitiation complex6-8. TFIIB contains a flexible linker domain that penetrates the active site cleft of RNA polymerase9-11. This linker domain confers two biochemically quantifiable activities on TFIIB, namely (i) the stimulation of the catalytic activity during the 'abortive' stage of transcript initiation, and (ii) an additional contribution to the specific recruitment of RNA polymerase into the preinitiation complex4,5,12 . We exploited the high-throughput purification method to generate single, double and triple substitution and deletions mutations within the TFIIB linker and to subsequently analyse them in functional assays for their stimulation effect on the catalytic activity of RNA polymerase4. Altogether, we generated, purified and analysed 381 mutants - a task which would have been time-consuming and laborious to perform manually. We produced and assayed the proteins in multiplicates which allowed us to appreciate any experimental variations and gave us a clear idea of the reproducibility of our results.
This method serves as a generic protocol for the purification of His-tagged proteins and has been successfully used to purify other recombinant proteins. It is currently optimised for the purification of 24 proteins but can be adapted to purify up to 96 proteins.

We describe a method for the affinity-tagged purification of recombinant proteins using liquid-handling robotics. This method is generally applicable to the small-scale purification of soluble His-tagged proteins in a high-throughput format.

טיהור תפוקה גבוהה של חלבונים רקומביננטי זיקה מתויגת-

X-ray crystallography is the method of choice for obtaining a detailed view of the structure of proteins. Such studies need to be complemented by further ...

Efficient Agroinfiltration of Plants for High-level Transient Expression of Recombinant Proteins

Mammalian cell culture is the major platform for commercial production of human vaccines and therapeutic proteins. However, it cannot meet the increasing worldwide demand for pharmaceuticals due to its limited scalability and high cost. Plants have shown to be one of the most promising alternative pharmaceutical production platforms that are robust, scalable, low-cost and safe. The recent development of virus-based vectors has allowed rapid and high-level transient expression of recombinant proteins in plants. To further optimize the utility of the transient expression system, we demonstrate a simple, efficient and scalable methodology to introduce target-gene containing Agrobacterium into plant tissue in this study. Our results indicate that agroinfiltration with both syringe and vacuum methods have resulted in the efficient introduction of Agrobacterium into leaves and robust production of two fluorescent proteins; GFP and DsRed. Furthermore, we demonstrate the unique advantages offered by both methods. Syringe infiltration is simple and does not need expensive equipment. It also allows the flexibility to either infiltrate the entire leave with one target gene, or to introduce genes of multiple targets on one leaf. Thus, it can be used for laboratory scale expression of recombinant proteins as well as for comparing different proteins or vectors for yield or expression kinetics. The simplicity of syringe infiltration also suggests its utility in high school and college education for the subject of biotechnology. In contrast, vacuum infiltration is more robust and can be scaled-up for commercial manufacture of pharmaceutical proteins. It also offers the advantage of being able to agroinfiltrate plant species that are not amenable for syringe infiltration such as lettuce and Arabidopsis. Overall, the combination of syringe and vacuum agroinfiltration provides researchers and educators a simple, efficient, and robust methodology for transient protein expression. It will greatly facilitate the development of pharmaceutical proteins and promote science education.

Plants offer a novel system for the production of pharmaceutical proteins on a commercial scale that is more scalable, cost-efficient and safe than current expression paradigms. In this study, we report a simple and convenient, yet scalable approach to introduce target-gene containing Agrobacterium tumefaciens into plants for protein transient expression.

Agroinfiltration היעילה של צמחים לביטוי חולף ברמה גבוהה של חלבונים רקומביננטי

Mammalian cell culture is the major platform for commercial production of human vaccines and therapeutic proteins. However, it cannot meet the increasing ...

Temporal Quantification of MAPK Induced Expression in Single Yeast Cells

The quantification of gene expression at the single cell level uncovers novel regulatory mechanisms obscured in measurements performed at the population level. Two methods based on microscopy and flow cytometry are presented to demonstrate how such data can be acquired. The expression of a fluorescent reporter induced upon activation of the high osmolarity glycerol MAPK pathway in yeast is used as an example. The specific advantages of each method are highlighted. Flow cytometry measures a large number of cells (10,000) and provides a direct measure of the dynamics of protein expression independent of the slow maturation kinetics of the fluorescent protein. Imaging of living cells by microscopy is by contrast limited to the measurement of the matured form of the reporter in fewer cells. However, the data sets generated by this technique can be extremely rich thanks to the combinations of multiple reporters and to the spatial and temporal information obtained from individual cells. The combination of these two measurement methods can deliver new insights on the regulation of protein expression by signaling pathways.

Two complementary methods based on flow cytometry and microscopy are presented which enable the quantification, at the single cell level, of the dynamics of gene expression induced by the activation of a MAPK pathway in yeast.

כימות זמניות של ביטוי MAPK מושרה בתאי שמרים יחיד

The quantification of gene expression at the  single cell level uncovers novel regulatory mechanisms obscured in measurements  performed at the population ...

High Throughput Quantitative Expression Screening and Purification Applied to Recombinant Disulfide-rich Venom Proteins Produced in E. coli

Escherichia coli (E. coli) is the most widely used expression system for the production of recombinant proteins for structural and functional studies. However, purifying proteins is sometimes challenging since many proteins are expressed in an insoluble form. When working with difficult or multiple targets it is therefore recommended to use high throughput (HTP) protein expression screening on a small scale (1-4&#160;ml cultures) to quickly identify conditions for soluble expression. To cope with the various structural genomics programs of the lab, a quantitative (within a range of 0.1-100 mg/L culture of recombinant protein) and HTP protein expression screening protocol was implemented and validated on thousands of proteins. The protocols were automated with the use of a liquid handling robot but can also be performed manually without specialized equipment.
Disulfide-rich venom proteins are gaining increasing recognition for their potential as therapeutic drug leads. They can be highly potent and selective, but their complex disulfide bond networks make them challenging to produce. As a member of the FP7 European Venomics project (<a href="http://www.venomics.eu">www.venomics.eu</a>), our challenge is to develop successful production strategies with the aim of producing thousands of novel venom proteins for functional characterization. Aided by the redox properties of disulfide bond isomerase DsbC, we adapted our HTP production pipeline for the expression of oxidized, functional venom peptides in the E. coli cytoplasm. The protocols are also applicable to the production of diverse disulfide-rich proteins. Here we demonstrate our pipeline applied to the production of animal venom proteins. With the protocols described herein it is likely that soluble disulfide-rich proteins will be obtained in as little as a week. Even from a small scale, there is the potential to use the purified proteins for validating the oxidation state by mass spectrometry, for characterization in pilot studies, or for sensitive micro-assays.

High Throughput Quantitative Expression Screening and Purification Applied to Recombinant Disulfide-rich Venom Proteins Produced in E. coli

A protocol for the quantitative, high throughput expression screening and analytical purification of fusion proteins from small-scale Escherichia coli cultures is described and applied to the expression of disulfide-rich animal venom protein targets.

הקרנת תפוקה גבוהה ביטוי כמותי וטיהור יישומים לחלבוני ארס רקומביננטי דיסולפיד עשירים הופק ב<em&gt; א coli</em

Escherichia coli (E. coli) is the most widely used expression system for the production of recombinant proteins for structural and functional studies. ...

Transient Expression of Proteins by Hydrodynamic Gene Delivery in Mice

Efficient expression of transgenes in vivo is of critical importance in studying gene function and developing treatments for diseases. Over the past years, hydrodynamic gene delivery (HGD) has emerged as a simple, fast, safe and effective method for delivering transgenes into rodents. This technique relies on the force generated by the rapid injection of a large volume of physiological solution to increase the permeability of cell membranes of perfused organs and thus deliver DNA into cells. One of the main advantages of HGD is the ability to introduce transgenes into mammalian cells using naked plasmid DNA (pDNA). Introducing an exogenous gene using a plasmid is minimally laborious, highly efficient and, contrary to viral carriers, remarkably safe. HGD was initially used to deliver genes into mice, it is now used to deliver a wide range of substances, including oligonucleotides, artificial chromosomes, RNA, proteins and small molecules into mice, rats and, to a limited degree, other animals. This protocol describes HGD in mice and focuses on three key aspects of the method that are critical to performing the procedure successfully: correct insertion of the needle into the vein, the volume of injection and the speed of delivery. Examples are given to show the application of this method to the transient expression of two genes that encode secreted, primate-specific proteins, apolipoprotein L-I (APOL-I) and haptoglobin-related protein (HPR).

In vivo transfection of naked DNA by hydrodynamic gene delivery introduces genes into the tissue of an animal with minimal inflammatory response. Sufficient amounts of gene product are generated such that gene function and regulation as well as protein structure and function can be analyzed.

ביטוי חולף של חלבונים על ידי הידרודינמית ג&#39;ין משלוח בעכברים

Efficient expression of transgenes in vivo is of critical importance in studying gene function and developing treatments for diseases. Over the past ...

High Yield Expression of Recombinant Human Proteins with the Transient Transfection of HEK293 Cells in Suspension

The art of producing recombinant proteins with complex post-translational modifications represents a major challenge for studies of structure and function. The rapid establishment and high recovery from transiently-transfected mammalian cell lines addresses this barrier and is an effective means of expressing proteins that are naturally channeled through the ER and Golgi-mediated secretory pathway. Here is one protocol for protein expression using the human HEK293F and HEK293S cell lines transfected with a mammalian expression vector designed for high protein yields. The applicability of this system is demonstrated using three representative glycoproteins that expressed with yields between 95-120 mg of purified protein recovered per liter of culture. These proteins are the human Fc&#947;RIIIa and the rat &#945;2-6 sialyltransferase, ST6GalI, both expressed with an N-terminal GFP fusion, as well as the unmodified human immunoglobulin G1 Fc. This robust system utilizes a serum-free medium that is adaptable for expression of isotopically enriched proteins and carbohydrates for structural studies using mass spectrometry and nuclear magnetic resonance spectroscopy. Furthermore, the composition of the N-glycan can be tuned by adding a small molecule to prevent certain glycan modifications in a manner that does not reduce yield.

Laboratory-scale production of eukaryotic proteins with appropriate post-translational modification represents a significant barrier. Here is a robust protocol with rapid establishment and turnaround for protein expression using a mammalian expression system. This system supports selective amino acid, selective labeling of proteins and small molecule modulators of glycan composition.

ביטוי תשואה גבוהה של חלבונים אנושיים רקומביננטי עם transfection חולף של תאי HEK293 בהשעיה

The art of producing recombinant proteins with complex post-translational modifications represents a major challenge for studies of structure and ...

Transient Expression and Cellular Localization of Recombinant Proteins in Cultured Insect Cells

Heterologous protein expression systems are used for the production of recombinant proteins, the interpretation of cellular trafficking/localization, and the determination of the biochemical function of proteins at the sub-organismal level. Although baculovirus expression systems are increasingly used for protein production in numerous biotechnological, pharmaceutical, and industrial applications, nonlytic systems that do not involve viral infection have clear benefits but are often overlooked and underutilized. Here, we describe a method for generating nonlytic expression vectors and transient recombinant protein expression. This protocol allows for the efficient cellular localization of recombinant proteins and can be used to rapidly discern protein trafficking within the cell. We show the expression of four&#160;recombinant proteins in a commercially available insect cell line, including two aquaporin proteins from the insect Bemisia tabaci, as well as subcellular marker proteins specific for the cell plasma membrane and for intracellular lysosomes. All recombinant proteins were produced as chimeras with fluorescent protein markers at their carboxyl termini, which allows for the direct detection of the recombinant proteins. The double transfection of cells with plasmids harboring constructs for the genes of interest and a known subcellular marker allows for live cell imaging and improved validation of cellular protein localization.

Nonlytic insect cell expression systems are underutilized for production, cellular trafficking/localization, and recombinant protein functional analysis. Here, we describe methods to generate expression vectors and subsequent transient protein expression in commercially available lepidopteran cell lines. The co-localization of Bemisia tabaci aquaporins with subcellular fluorescent marker proteins is also presented.

ביטוי חולף ואת סלולר לוקליזציה של חלבונים רקומביננטי תאים בתרבית חרקים

Heterologous protein expression systems are used for the production of recombinant proteins, the interpretation of cellular trafficking/localization, and ...