scholarly journals Protein Engineering with A Glycosylation Circuit Enables Improved Enzyme Characteristics

2021 ◽  
Author(s):  
Eray Bozkurt ◽  
Irem Cagil ◽  
Ebru Kehribar ◽  
Musa Isilak ◽  
Urartu Ozgur Safak Seker

Protein glycosylation is one of the most crucial and common post-translational modifications. It plays a fate-determining role and can alter many properties of proteins, making it an interesting for many biotechnology applications. The discovery of bacterial glycosylation mechanisms, opened a new perspective and transfer of C.jejuni N-linked glycosylation into laboratory work-horse E. coli increased research pace in the field exponentially. It has been previously showed that utilizing N-Linked Glycosylation, certain recombinant proteins have been furnished with improved features, such as stability and solubility. In this study, we utilized N-linked Glycosylation to glycosylate alkaline phosphatase (ALP) enzyme in E. coli and investigate the effects of glycosylation on an enzyme. Considering the glycosylation mechanism is highly dependent on the acceptor protein, ALP constructs carrying glycosylation tag at different locations of the gene has been created and glycosylation rates have been calculated. The most glycosylated construct has been selected for comparison with the native enzyme. We investigated the performance of glycosylated ALP in terms of its thermostability, proteolytic stability, tolerance to suboptimal pH and under denaturing conditions. Studies showed that glycosylated ALP performed remarkably better at optimal and harsh conditions Therefore, N-linked Glycosylation mechanism can be employed for enzyme engineering purposes and is a useful tool for industrial applications that require enzymatic activity.

Author(s):  
Arshpreet Bhatwa ◽  
Weijun Wang ◽  
Yousef I. Hassan ◽  
Nadine Abraham ◽  
Xiu-Zhen Li ◽  
...  

Recombinant proteins are becoming increasingly important for industrial applications, where Escherichia coli is the most widely used bacterial host for their production. However, the formation of inclusion bodies is a frequently encountered challenge for producing soluble and functional recombinant proteins. To overcome this hurdle, different strategies have been developed through adjusting growth conditions, engineering host strains of E. coli, altering expression vectors, and modifying the proteins of interest. These approaches will be comprehensively highlighted with some of the new developments in this review. Additionally, the unique features of protein inclusion bodies, the mechanism and influencing factors of their formation, and their potential advantages will also be discussed.


Author(s):  
Isabela Victorino da Silva Amatto ◽  
Nathalia Gonsales da Rosa‐Garzon ◽  
Flávio Antônio de Oliveira Simões ◽  
Fernanda Santiago ◽  
Nathália Pereira da Silva Leite ◽  
...  

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 422.1-422
Author(s):  
M. Volkov ◽  
A. S. B. Kampstra ◽  
K. van Schie ◽  
J. Kwekkeboom ◽  
T. Huizinga ◽  
...  

Background:Rheumatoid arthritis (RA) is characterized by autoantibodies against post-translationally modified proteins (AMPA) such as citrullinated, carbamylated and acetylated proteins. Importantly, these antibodies are highly multireactive, as they often recognize more than one of these post-translational modifications. Despite extensive research, the antigens inducing the breach of tolerance remain unknown, although microbial antigens are often suspected. Various bacteria are known to be capable of acetylation, therefore, it is intriguing to know what mechanisms can underlie the breach of tolerance towards acetylated proteins and development of anti-acetylated protein antibodies (AAPA).Objectives:To investigate whether acetylated proteins of bacterial origin (1) are recognized by human derived AMPA and AMPA expressing B cells; and (2) can induce AMPA development when used to immunize mice.Methods:Acetylated E. coli proteins were acquired with two separate methods (Figure 1A): by culturing E. coli in a condition promoting auto-acetylation (intrinsically acetylated bacterial proteins, IABP), or by directly acetylating lysate-derived proteins via a chemical reaction (extrinsically acetylated BP, EABP). Acetylated ovalbumin (AcOVA) served as positive control for AAPA induction in mice, non-acetylated BP (NABP) and phosphate buffer saline (PBS) served as negative control. Mice were immunized with these proteins and the resulting antibody response was studied by ELISA. Furthermore, EABP/IABP/NABP were investigated for recognition by human-derived AAPA with ELISA and AAPA-expressing B cells with spleen tyrosine kinase (Syk) phosphorylation assay; acetylated human fibrinogen and native fibrinogen served as positive and negative control.Results:Repetitive immunization of mice with EABP resulted in an AMPA response recognizing acetylated, carbamylated and citrullinated proteins. AMPA titers in these mice exceeded the titers in the positive control mice immunized with AcOVA and were substantially higher than in the NABP-immunized mice (Figure 1B). Human-derived monoclonal AAPA recognized EABP and IABP (not shown). B cell activation (measured by Syk phosphorylation) assay indicated that AAPA expressing B cells recognized EABP and (to a lesser extent) IABP, but not NABP (Figure 1C).Conclusion:Acetylated bacterial proteins are potent antigens that can induce cross-reactive AMPA responses in mice and they are recognized by human AAPA. This suggests that acetylated bacterial proteins could possibly be involved in the breach of tolerance in RA.Acknowledgements:We thank Dr. Can Araman and Prof. Chunaram Choudhary for their advice regarding optimization of bacterial auto-acetylation.Disclosure of Interests:None declared


2006 ◽  
Vol 72 (8) ◽  
pp. 5225-5231 ◽  
Author(s):  
Emmanuel Frachon ◽  
Vincent Bondet ◽  
Hélène Munier-Lehmann ◽  
Jacques Bellalou

ABSTRACT A multiple microfermentor battery was designed for high-throughput recombinant protein production in Escherichia coli. This novel system comprises eight aerated glass reactors with a working volume of 80 ml and a moving external optical sensor for measuring optical densities at 600 nm (OD600) ranging from 0.05 to 100 online. Each reactor can be fitted with miniature probes to monitor temperature, dissolved oxygen (DO), and pH. Independent temperature regulation for each vessel is obtained with heating/cooling Peltier devices. Data from pH, DO, and turbidity sensors are collected on a FieldPoint (National Instruments) I/O interface and are processed and recorded by a LabVIEW program on a personal computer, which enables feedback control of the culture parameters. A high-density medium formulation was designed, which enabled us to grow E. coli to OD600 up to 100 in batch cultures with oxygen-enriched aeration. Accordingly, the biomass and the amount of recombinant protein produced in a 70-ml culture were at least equivalent to the biomass and the amount of recombinant protein obtained in a Fernbach flask with 1 liter of conventional medium. Thus, the microfermentor battery appears to be well suited for automated parallel cultures and process optimization, such as that needed for structural genomics projects.


2014 ◽  
Vol 185 ◽  
pp. S70
Author(s):  
Boguslaw Lupa ◽  
Krzysztof Stawujak ◽  
Igor Rozanski ◽  
Justyna Stec-Niemczyk

TECHNOLOGY ◽  
2015 ◽  
Vol 03 (02n03) ◽  
pp. 80-83
Author(s):  
Mark Polikovsky ◽  
Eshel Ben-Jacob ◽  
Alin Finkelshtein

Cellulose hydrolysis has many industrial applications such as biofuel production, food, paper and textile manufacture. Here, we present a novel approach to cellulose hydrolysis using a consortium of motile bacteria, Paenibacillus vortex, that can swarm on solid medium carrying a non-motile recombinant E. coli cargo strain expressing the β-glucosidase and cellulase genes that facilitate the hydrolysis of cellulose. These two species cooperate; the relationship is mutually beneficial: the E. coli is dispersed over long distances, while the P. vortex bacteria gain from the supply of cellulose degradation products. This enables the use of such consortia in this area of biotechnology.


2007 ◽  
Vol 85 (2) ◽  
pp. 203-208 ◽  
Author(s):  
Hongmei Dong ◽  
Xiaohu Xu ◽  
Mohong Deng ◽  
Xiaojun Yu ◽  
Hu Zhao ◽  
...  

The aim of the study was to prepare an active recombinant human perforin by comparing 5 candidate segments of human perforin. Full-length perforin, MAC1 (28–349 aa), MAC2 (166–369 aa), C-100, and N-60 of human perforin were selected as candidate active segments and designated, respectively, HP1, HP2, HP3, HP4, and HP5. The target genes were amplified by PCR and the products were individually subcloned into pGEM-T. The genes for HP1, HP2, HP3, and HP5 were subcloned into pET-DsbA, whereas pET-41a (+) was used as the expression vector of HP4. The fusion proteins were expressed in Escherichia coli BL21pLysS(DE3) and purified using nickel nitrilotriacetic acid (NTA) agarose affinity chromatography. The hemolysis microassay was used as an activity assay of fusion protein. From this study, we obtained the recombinant plasmids pGEM-T-HP1, -HP2, -HP3, -HP4 and -HP5, consisting of 1600, 960, 600, 300bp, and 180, respectively. From these recombinant plasmids, expression plasmids were successfully constructed and expressed in E. coli BL21pLysS(DE3). The resultant fusion proteins, affinity purified using Ni–NTA, were ~80, 58, 45, 44, and 30 kDa, respectively. The recombinant proteins were assayed for activity on hemolysis. HP2 and HP5 were the only recombinant proteins that were active in hemolysis, and the hemolytic function was concentration dependent. These results demonstrate that active recombinant forms of perforin can be synthesized in a prokaryote model. The recombinant N-60 and MAC1 (28–349 aa) of human perforin have the function of forming pores. Our study provides the experimental basis for further investigation on the application of perforin.


2005 ◽  
Vol 70 (12) ◽  
pp. 1401-1407 ◽  
Author(s):  
Sandra Markovic ◽  
Sandra Vojnovic ◽  
Milija Jovanovic ◽  
Branka Vasiljevic

The KgmB methylase from Streptomyces tenebrarius was expressed and purified using the QIAexpress System. Two expression vectors were made: pQEK-N, which places a (His)6 tag at the N-terminus, and pQEK-C, which places a (His)6 tag at the C-terminus of the recombinant KgmB protein. Kanamycin resistance of the E. coli cells containing either the pQEK-N or the pQEK-C recombinant plasmids confirmed the functionality of both KgmB-His fusion proteins in vivo. Interestingly, different levels of expression were observed between these two recombinant proteins. Namely, KgmB methylase with the (His)6 tag at the N-terminus showed a higher level of expression. Purification of the (His)6-tagged proteins using Ni-NTA affinity chromatography was performed under native conditions and the KgmB methylase with (His)6 tag at the N-terminus was purified to homogeneity >95 %. The recombinant KgmB protein was detected on a Western blot using anti-Sgm antibodies.


Author(s):  
Tiago Oliveira ◽  
Morten Thaysen-Andersen ◽  
Nicolle H. Packer ◽  
Daniel Kolarich

Protein glycosylation is one of the most common post-translational modifications that are essential for cell function across all domains of life. Changes in glycosylation are considered a hallmark of many diseases, thus making glycoproteins important diagnostic and prognostic biomarker candidates and therapeutic targets. Glycoproteomics, the study of glycans and their carrier proteins in a system-wide context, is becoming a powerful tool in glycobiology that enables the functional analysis of protein glycosylation. This ‘Hitchhiker's guide to glycoproteomics’ is intended as a starting point for anyone who wants to explore the emerging world of glycoproteomics. The review moves from the techniques that have been developed for the characterisation of single glycoproteins to technologies that may be used for a successful complex glycoproteome characterisation. Examples of the variety of approaches, methodologies, and technologies currently used in the field are given. This review introduces the common strategies to capture glycoprotein-specific and system-wide glycoproteome data from tissues, body fluids, or cells, and a perspective on how integration into a multi-omics workflow enables a deep identification and characterisation of glycoproteins — a class of biomolecules essential in regulating cell function.


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