Non-Conjugated Copoly(Arylene Ether Ketone) for the Current-Collecting System of a Solar Cell with Indium Tin Oxide Electrode.

The mechanism of charge carrier transport in the indium tin oxide (ITO)/polymer/Cu structure is studied, where thin films of copoly(arylene ether ketone) with cardo fluorene moieties are used. This copoly(arylene ether ketone) is non-conjugated polymer which has the properties of electronic switching from the insulating to the highly conductive state. The dependence on the polymer film thickness of such parameters as the potential barrier at the ITO/polymer interface, the concentration of charge carriers, and their mobility in the polymer is studied for the first time.

Fundamentals of Baculovirus Expression and Applications.

In 1982 E. coli produced human insulin, the world's first recombinant DNA drug, was approved by the FDA. Since this historical event, remarkable progress has been made in developing bacterial, yeast, mammalian and insect cell protein expression systems that are used to produce recombinant proteins for both research and clinical applications.

Development of the First Cisgenic Apple with Increased Resistance to Fire Blight.

The generation and selection of novel fire blight resistant apple genotypes would greatly improve the management of this devastating disease, caused by Erwinia amylovora. Such resistant genotypes are currently developed by conventional breeding, but novel breeding technologies including cisgenesis could be an alternative approach. A cisgenic apple line C44.

Engineering fire blight resistance into the apple cultivar 'Gala' using the FB_MR5 CC-NBS-LRR resistance gene of Malus × robusta 5.

The fire blight susceptible apple cultivar Malus × domestica Borkh. cv. 'Gala' was transformed with the candidate fire blight resistance gene FB_MR5 originating from the crab apple accession Malus × robusta 5 (Mr5).

Oxalotrophy, a widespread trait of plant-associated Burkholderia species, is involved in successful root colonization of lupin and maize by Burkholderia phytofirmans.

Plant roots and shoots harbor complex bacterial communities. Early seed and plantlet colonization plays a key role in determining which bacterial populations will successfully invade plant tissues, yet the mechanisms enabling plants to select for beneficial rather than harmful populations are largely unknown. In this study, we demonstrate a role of oxalate as a determinant in this selection process, using members of the genus Burkholderia as model organisms.

Baculovirus: an insect-derived vector for diverse gene transfer applications.

Insect-derived baculoviruses have emerged as versatile and safe workhorses of biotechnology. Baculovirus expression vectors (BEVs) have been applied widely for crop and forest protection, as well as safe tools for recombinant protein production in insect cells. However, BEVs ability to efficiently transduce noninsect cells is still relatively poorly recognized despite the fact that efficient baculovirus-mediated in vitro and ex vivo gene delivery into dormant and dividing vertebrate cells of diverse origin has been described convincingly by many authors.

Sucrose and fetal bovine serum maintain stability and activity of the budded baculovirus during dehydration.

Budded baculovirus has become an important vector for gene delivery, vaccine development, protein expression in insect and mammalian cells, and many other emerging applications. For high-throughput applications or for long-term storage and long-distance shipping, it would be useful if the infectivity and transduction abilities of baculovirus could be maintained at room temperature under dehydrated condition. The aim of this study was to design an optimized formula that preserves the activity of baculovirus stocks during prolonged periods of dehydration at various storage temperatures.

Baculovirus gene delivery: a flexible assay development tool.

Modern drug discovery programs utilize a wide variety of technologies to aid in identification of potential drug targets, and progress them through the often long and winding path of finding novel drug-like molecules. Recombinant cell-based assays are an important tool in the drug discovery process for investigating the biological mechanisms of potential drug targets and conducting screening campaigns in the hunt for biologically active molecules. Historically, stable cell lines expressing the target protein(s) of interest have been used for these assays.

BacMam technology and its application to drug discovery.

The recombinant baculovirus/insect cell system was firmly established as a leading method for recombinant protein production when a new potential use for these viruses was revealed in 1995. It was reported that engineered recombinant baculoviruses could deliver functional expression cassettes to mammalian cell types; a system which has come to be known as BacMam gene delivery. In the field of high-throughput screening the failure of many common transient gene delivery methods in reproducibility and cell survival has caused investigators to routinely apply stable cell lines in support of cell-based assays.

Baculovirus expression vectors for insect and mammalian cells.

Functional expression of recombinant proteins has become a routine, but critical tool in modern molecular biology. Since their introduction, the use of baculovirus vectors to produce proteins for purification has become one of the most widely-used viral gene delivery systems as expression levels obtained are difficult to match with any other eukaryotic expression system. Extensive engineering to simplify and accelerate the process of recombinant virus construction has made this system accessible to virtually any modern biological laboratory.

Implementation of BacMam virus gene delivery technology in a drug discovery setting.

Membrane protein targets constitute a key segment of drug discovery portfolios and significant effort has gone into increasing the speed and efficiency of pursuing these targets. However, issues still exist in routine gene expression and stable cell-based assay development for membrane proteins, which are often multimeric or toxic to host cells. To enhance cell-based assay capabilities, modified baculovirus (BacMam virus) gene delivery technology has been successfully applied to the transient expression of target proteins in mammalian cells.

Baculovirus as versatile vectors for protein expression in insect and mammalian cells.

Today, many thousands of recombinant proteins, ranging from cytosolic enzymes to membrane-bound proteins, have been successfully produced in baculovirus-infected insect cells. Yet, in addition to its value in producing recombinant proteins in insect cells and larvae, this viral vector system continues to evolve in new and unexpected ways. This is exemplified by the development of engineered insect cell lines to mimic mammalian cell glycosylation of expressed proteins, baculovirus display strategies and the application of the virus as a mammalian-cell gene delivery vector.

Material flow analysis of RDF-production processes.

The authors evaluate the possibilities of modifying the chemical characteristics of refuse-derived fuels (RDF) that are processed from residual household waste by mechanical operations to achieve and assure quality targets for relevant chemical concentrations, especially for heavy metals and chlorine. Quality assurance in the production of RDF demands that, together with an enrichment of the calorific value, highly toxic waste components are selectively separated and concentrated in a small stream to produce high yields of a relatively low polluted fuel. Based on the method of material flow analysis, a process evaluation is developed that considers the aspect of minimizing hazardous chemicals along with classical process data such as yield and product quality.

BacMam recombinant baculoviruses in G protein-coupled receptor drug discovery.

With completion of the sequencing of the human and mouse genomes, the primary sequences of close to 400 non-olfactory G protein-coupled receptors (GPCRs) have been determined. There are intensive efforts within the pharmaceutical industry to discover and develop new therapeutic agents acting via GPCRs. In addition, there is a concerted effort to identify potential new drug targets from the remaining 150+orphan GPCRs through the identification of their ligands.

Influence of promoter choice and trichostatin A treatment on expression of baculovirus delivered genes in mammalian cells.

The expression of recombinant proteins following transduction of CHO cells with recombinant baculoviruses containing a mammalian expression cassette with the CMV-promoter is enhanced by the addition of trichostatin A (TSA), a specific histone deacetylase inhibitor. To further investigate the effect of TSA treatment on protein production following BacMam transduction, viruses containing various viral promoters (SV40, CMV, and RSV) and one cellular promoter (human ubiquitin C) were compared with regard to expression level of a gfp-luciferase fusion protein following transduction of CHO, COS-1, and HEK293 cells. The overall effect on expression appears to be cell specific, indicating that different mechanisms are active within different cell lines.

A cell-based time-resolved fluorescence assay for selection of antibody reagents for G protein-coupled receptor immunohistochemistry.

A cell-based time-resolved fluorescence (celTRF) immunoassay is described for pre-screening antibodies to G protein-coupled receptor (GPCR) peptides that predicts suitability for immunohistochemistry (IHC). Rat GPCRs were expressed in Saos-2 human osteosarcoma cells via recombinant baculoviruses designed for mammalian cell expression, i.e.

Recombinant baculoviruses used to study estrogen receptor function in human osteosarcoma cells.

We report that modified baculoviruses, termed BacMam viruses, can efficiently deliver multiple genes into mammalian cells to generate a heterologous transcription factor/reporter gene system. Using human estrogen receptor (ER) as a model nuclear receptor, we demonstrate how this approach can be successfully applied to assay development in Saos-2 human osteosarcoma cells. BacMam viruses containing full-length cDNAs were constructed for both human ER subtypes, ERalpha and ERbeta, and a third BacMam virus containing an ER-responsive reporter gene cassette.

Baculovirus-mediated gene delivery into mammalian cells.

A relatively recent advance in the use of recombinant baculoviruses is their use for delivery of genes and genetic elements into mammalian cells. Baculovirus vectors retrofitted with mammalian gene promoters have been shown to efficiently deliver and express genes in a broad assortment of cell types. These baculovirus transductions are simple to perform, reproducible, and demonstrate no overt cell toxicity.

Identification of peptides that inhibit the DNA binding, trans-activator, and DNA replication functions of the human papillomavirus type 11 E2 protein.

Peptide antagonists of the human papillomavirus type 11 (HPV-11) E2-DNA association were identified using a filamentous bacteriophage random peptide library. Synthetic peptides antagonized the E2-DNA interaction, effectively blocked E2-mediated transcriptional activation of a reporter gene in cell culture, and inhibited E1-E2-mediated HPV-11 DNA replication in vitro. These peptides may prove to be useful tools for characterizing E2 function and for exploring the effectiveness of E2-inhibitor-based treatments for HPV-associated diseases.

Titration of KATP channel expression in mammalian cells utilizing recombinant baculovirus transduction.

A variety of transfection approaches have been used to deliver plasmids encoding ion channel genes into cells. We have used the baculovirus transduction system, BacMam, to demonstrate transient expression of multi-subunit KATP channels in CHO-K1 and HEK-293 EBNA cells using sulfonylurea receptor 1 (SUR), SUR2A, SUR2B, and KIR 6.2 genes.

Viruses as gene delivery vectors: application to gene function, target validation, and assay development.

A Biochemical Pharmacology Discussion Group Conference, was held at the headquarters of the New York Academy of Sciences on December 4, 2001 as part of an ongoing series designed to highlight and review areas important to modern drug development (Figure 1). Briefly introduced by Tom Kost (GlaxoSmithKline) and Michael Lotze (University of Pittsburgh), the focus was on the intersection of genomics, proteomics, and now "viromics." The latter term refers to the use of viruses and viral gene transfer to explore the complexity arising from the vast array of new targets available from the human and murine genomes.

Recombinant baculoviruses as mammalian cell gene-delivery vectors.

The baculovirus expression system has been used extensively for the expression of recombinant proteins in insect cells. Recently, recombinant baculovirus vectors engineered to contain mammalian cell-active promoter elements, have been used successfully for transient and stable gene delivery in a broad spectrum of primary and established mammalian cells. The application of modified baculoviruses for in vivo gene delivery has also been demonstrated.

Biotechnology. Paper Alert.

A selection of interesting papers that were published in the two months before our press date in major journals most likely to report significant results in biotechnology.