Cloning and Characterization of SpcrtR and Its Expression in Escherichia Coli for Zeaxanthin Production

Zeaxanthin is produced by a series of enzyme catalytic reactions. β-carotene hydroxylase is a key rate-limiting enzyme that catalyzes the conversion of β-carotene to zeaxanthin. The purpose of this study was to clone and express the Spirulina platensis β-carotene hydroxylase gene (SpcrtR) in E. coli. SpcrtR was amplified using specific primers and cloned in vector pGEX-6p-1, the SpcrtR protein (35kDa) was expressed from pGEX-6p-1-SpcrtR in E. coli. Gene expression was analyzed by SDS-PAGE and western blotting. The accumulation of carotenoids was detected by high-performance liquid chromatography (HPLC). SDS-PAGE and western blotting analysis confirmed that SpcrtR protein (35kDa) was expressed in E. coli expression system. Further, the HPLC results demonstrated that SpcrtR can partially catalyze β-carotene to produce zeaxanthin in E. coli. Zeaxanthin and β-carotene yields in recombinant E.coli were 85.71% (±0.4%) and 14.7% (±0.6%), respectively. The results in our study verified that SpCRTR enzyme partially catalyzes the substrate β-carotene to form zeaxanthin. Overall, SpCRTR provides a new choice for enzymatic zeaxanthin production.

Cloning and Expression of N-CFTX-1 Antigen from Chironex fleckeri in Escherichia coli and Determination of Immunogenicity in Mice

Background: Most jellyfish species are poisonous. Human victims of jellyfish sting each year are 120 million. Chironex fleckeri is a venomous box jellyfish that inflicts painful and potentially fatal stings to humans. The CfTX1 is one of the antigenic proteins of venom that is suggested to stimulate the immune system for treatment and vaccine. This study aimed to clone and express the CfTX-1 antigen in E. coli and then to determine the synthesis of related antibody in the mice. Methods: The study was performed in the Persian Gulf and Oman Sea Ecology Research Center, Bandar Abbas, Iran in autumn 2016. The synthetic CfTX-1 gene in PUC57 plasmid was purchased from Nedaye Fan Company. The 723 bp fragment of N-CfTX-1 was amplified by PCR, PUC57 plasmid containing CfTX-1 with BamHI SalI restriction enzyme sites were subcloned in pET28a [+] expression vector and transformed into E. coli BL21 (DE3). The CfTX-1 gene expression was induced by IPTG. Then antibody produced from the mice serum were isolated and confirmed by ELISA. After protein purification, resulted antigen was injected to mice in 4 repeats and then evaluated the rate of antibody in mice serum. Mice were challenged by the Carybdea alata. Results: The 726 bp of N-CfTX-1 were cloned in a vector of expression pET28a [+] and confirmed by PCR, sequencing and enzymatic analysis. Moreover, the recombinant protein was confirmed by SDS-PAGE and Western blotting. Then the antibody was isolated from mice serum and confirmed by ELISA test. The results showed that immunized mice tolerated 50x LD501 of jellyfish venom. Conclusion: The CfTX-1 recombinant protein was able to protect the BALB/c mice against jellyfish venom. The produced protein can be used as a candidate for vaccine against jellyfish venom.

Engineered Artificial MicroRNA Precursors Facilitate Cloning and Gene Silencing in Arabidopsis and Rice

Plant genome sequences are presently deciphered at a staggering speed, due to the rapid advancement of high-throughput sequencing technologies. However, functional genomics significantly lag behind due to technical obstacles related to functional redundancy and mutant lethality. Artificial microRNA (amiRNA) technology is a specific, reversible, and multiplex gene silencing tool that has been frequently used in generating constitutive or conditional mutants for gene functional interrogation. The routine approach to construct amiRNA precursors involves multiple polymerase chain reactions (PCRs) that can increase both time and labor expenses, as well as the chance to introduce sequence errors. Here, we report a simplified method to clone and express amiRNAs in Arabidopsis and rice based on the engineered Arabidopsis miR319a or rice miR528 precursor, which harbor restriction sites to facilitate one-step cloning of a single PCR product. Stem-loop reverse-transcriptase quantitative PCR (RT-qPCR) and functional assays validated that amiRNAs can be accurately processed from these modified precursors and work efficiently in plant protoplasts. In addition, Arabidopsis transgenic plants overexpressing the modified miR319a precursor or its derived amiRNA could exhibit strong gene silencing phenotypes, as expected. The simplified amiRNA cloning strategy will be broadly useful for functional genomic studies in Arabidopsis and rice, and maybe other dicotyledon and monocotyledon species as well.

Cloning and Expression of theγ-Polyglutamic Acid Synthetase GenepgsBCA inBacillus subtilisWB600

To clone and express theγ-polyglutamic acid (γ-PGA) synthetase genepgsBCA inBacillus subtilis, a pWB980 plasmid was used to construct and transfect the recombinant expression vector pWB980-pgsBCA intoBacillus subtilisWB600.PgsBCAwas expressed under the action of a P43 promoter in the pWB980 plasmid. Our results showed that the recombinant bacteria had the capacity to synthesizeγ-PGA. The expression product was secreted extracellularly into the fermentation broth, with a product yield of 1.74 g/L or higher.γ-PGA samples from the fermentation broth were purified and characterized. Hydrolysates ofγ-PGA presented in single form, constituting simple glutamic acid only, which matched the characteristics of the infrared spectra of theγ-PGA standard, and presented as multimolecular aggregates with a molecular weight within the range of 500–600 kDa. Expressing theγ-PGA synthetase genepgsBCAinB. subtilissystem has potential industrial applications.

Cloning, Expression, and Characterization of a Novel Thermophilic Monofunctional Catalase fromGeobacillussp. CHB1

Catalases are widely used in many scientific areas. A catalase gene (Kat) fromGeobacillussp. CHB1 encoding a monofunctional catalase was cloned and recombinant expressed inEscherichia coli(E. coli), which was the first time to clone and express this type of catalase ofgenus Geobacillusstrains as far as we know. ThisKatgene was 1,467 bp in length and encoded a catalase with 488 amino acid residuals, which is only 81% similar to the previously studiedBacillussp. catalase in terms of amino acid sequence. Recombinant catalase was highly soluble inE. coliand made up 30% of the totalE. coliprotein. Fermentation broth of the recombinantE. colishowed a high catalase activity level up to 35,831 U/mL which was only lower than recombinantBacillussp. WSHDZ-01 among the reported catalase production strains. The purified recombinant catalase had a specific activity of 40,526 U/mg andKmof 51.1 mM. The optimal reaction temperature of this recombinant enzyme was 60°C to 70°C, and it exhibited high activity over a wide range of reaction temperatures, ranging from 10°C to 90°C. The enzyme retained 94.7% of its residual activity after incubation at 60°C for 1 hour. High yield and excellent thermophilic properties are valuable features for this catalase in industrial applications.

Candidate Effector Proteins of the Rust Pathogen Melampsora larici-populina Target Diverse Plant Cell Compartments

Rust fungi are devastating crop pathogens that deliver effector proteins into infected tissues to modulate plant functions and promote parasitic growth. The genome of the poplar leaf rust fungus Melampsora larici-populina revealed a large catalog of secreted proteins, some of which have been considered candidate effectors. Unraveling how these proteins function in host cells is a key to understanding pathogenicity mechanisms and developing resistant plants. In this study, we used an effectoromics pipeline to select, clone, and express 20 candidate effectors in Nicotiana benthamiana leaf cells to determine their subcellular localization and identify the plant proteins they interact with. Confocal microscopy revealed that six candidate effectors target the nucleus, nucleoli, chloroplasts, mitochondria, and discrete cellular bodies. We also used coimmunoprecipitation (coIP) and mass spectrometry to identify 606 N. benthamiana proteins that associate with the candidate effectors. Five candidate effectors specifically associated with a small set of plant proteins that may represent biologically relevant interactors. We confirmed the interaction between the candidate effector MLP124017 and TOPLESS-related protein 4 from poplar by in planta coIP. Altogether, our data enable us to validate effector proteins from M. larici-populina and reveal that these proteins may target multiple compartments and processes in plant cells. It also shows that N. benthamiana can be a powerful heterologous system to study effectors of obligate biotrophic pathogens.

CLONING, EXPRESSION AND PRELIMINARY ANTIGENICITY ANALYSIS OF STRUCTURAL PROTEINS OF A KOI HERPESVIRUS ISOLATE FROM KOI, CYPRINUS CARPIO IN TAIWAN

The aim of this study was to clone and express the ORF72 and ORF92 genes of koi herpesvirus (KHV) in a prokaryotic system and to examine the antigenicity of recombinant proteins. Phylogenetic analysis revealed that both ORF72 and ORF92 had 100% homology with KHV-J, and 99% homology with those from KHV-U and KHV-I in nucleotides. This suggests that the KHV isolate in Taiwan is more closely related to the Japanese strain (Asian genotype). In the antigenicity analysis, the crude recombinant ORF72 and ORF92 capsid proteins reacted with the positive sera of the survival fish after a KHV outbreak, indicating that these recombinant capsid proteins might mimic antigens of the wild type KHV to induce an immunological response in the infected host. Our results demonstrated potential for general applicability to serological tests and vaccine development.

Comparison of natural and recombinant tissue factor proteins: new insights

Tissue factor (TF), an initiator of blood coagulationin vivo, is expressed in a variety of cells. Sufficient natural TF has been isolated to clone and express recombinant proteins ranging from full-length TF to its extracellular domain. Because of the limited availability of natural TF, recombinant proteins have been used as surrogates. Despite the differences in their post-translational modifications, it has been accepted that membrane-anchored recombinant TFs are quite similar to the natural TF. Recent studies, however, have shown that post-translational modifications play an important role in TF-triggered thrombin generation.

Expression andIn SilicoAnalysis of the Recombinant Bovine Papillomavirus E6 Protein as a Model for Viral Oncoproteins Studies

Bovine papillomaviruses (BPVs) are recognized as the causal agents of economical relevant diseases in cattle, associated with the development of tumors in skin and mucosa. The oncogenesis process is mainly associated with different viral oncoprotein expressions, which are involved in cell transformation. The expression and characterization of recombinant viral oncoproteins represent an attractive strategy to obtain biotechnological products as antibodies and potential vaccines, Thus, the aim of this work was to clone and express the BPV-1 and BPV-2 E6 recombinant proteins and performin silicoanalysis in order to develop a strategy for the systematic study of other papillomaviruses oncoproteins. The results demonstrated that BPV-1 and BPV-2 E6 recombinant proteins were expressed and purified from bacterial system as well as itsin silicoanalysis was performed in order to explore and predict biological characteristics of these proteins.