Biotechnological Advances in Luciferase Enzymes

This chapter explores the history of the bioengineering advances that have been applied to common luciferase enzymes and the improvements that have been accomplished by this work. The primary focus is placed on firefly luciferase (FLuc), Gaussia luciferase (GLuc), Renilla luciferase (RLuc), Oplophorus luciferase (OLuc; NanoLuc), and bacterial luciferase (Lux). Beginning with the cloning and exogenous expression of each enzyme, their step-wise modifications are presented and the new capabilities endowed by each incremental advancement are highlighted. Using the historical basis of this information, the chapter concludes with a prospective on the overall impact these advances have had on scientific research and provides an outlook on what capabilities future advances could unlock

Autobioluminescent Cellular Models for Enhanced Drug Discovery

Autobioluminescent cellular models are emerging tools for drug discovery that rely on the expression of a synthetic, eukaryotic‐optimized luciferase that does not require an exogenous chemical substrate to produce its resultant output signal. These models can therefore self‐modulate their output signals in response to metabolic activity dynamics and avoid the sample destruction and intermittent data acquisition limitations of traditional fluorescent or chemically stimulated bioluminescent approaches. While promising for reducing drug discovery costs and increasing data acquisition relative to alternative approaches, these models have remained relatively untested for drug discovery applications due to their recent emergence within the field. This chapter presents a history and background of these autobioluminescent cellular models to offer investigators a generalized point of reference for understanding their capabilities and limitations and provides side‐by‐side comparisons between autobioluminescent and traditional, substrate‐requiring toxicology screening platforms for pharmaceutically relevant three‐dimensional and high‐throughput screening applications to introduce investigators to autobioluminescence as a potential new drug discovery toolset

Rapid, High-Throughput Detection of Endocrine Disrupting Chemicals Using Autobioluminescent Cellular Bioreporters

Dunia dongeng merupakan dunia yang menakjubkan terutama untuk anak anak. Melalui dongeng komunikasi dan kedekatan emosional akan terbentuk antara pendongeng dengan pendengar dongeng. Transfer nilai-nilai yang terkandung dalam sebuah dongeng dapat dipahami dengan cara mendongeng. Kegiatan belajar mengajar merupakan suatu proses kegiatan yang melibatkan antara guru dan siswa melakukan pembelajaran dan berinteraksi untuk mencapai tujuan pembelajaran. Agar tujuan pembelajaran dapat dicapai, khususnya untuk pembelajaran mendongeng maka guru dituntut untuk memiliki kemampuan mendongeng dan guru harus mampu mempersiapkan komponen-komponen penunjang pembelajaran, mulai dari menjabarkan kurikulum hingga membuat skenario pembelajaran dikelas. Pembelajaran dengan mengintegrasikan media, dianggap lebih efektif dibandingkan dengan tanpa mengintegrasikan media apalagi pada tingkat pendidikan dasar. Teknik pagelaran wayang beber dapat digunakan sebagai alternatif yang tepat untuk menyampaikan pembelajaran mendongeng karena teknik pagelaran ini tidak serumit pagelaran wayang yang lainnya

Rapid, High-Throughput Detection of Endocrine Disrupting Chemicals Using Autobioluminescent Cellular Bioreporters

Overexposure to endocrine disruptor chemicals (EDCs) can result in serious health problems, yet they are commonly found in everyday items such as pesticides, personal care products, nutritional supplements, and plastics. The U.S. Environmental Protection Agency, along with other such agencies from around the world, have therefore mandated that new approaches be designed to screen these products for the presence of EDCs. However, despite the presence of several types of extant EDC detection assays, there still exists a backlog approaching 87,000 chemicals currently awaiting screening. Autobioluminescent detection systems, which utilize cellular bioreporters capable of autonomously modulating bioluminescent signals without the need for external stimulation or investigator interaction, provide an attractive means for addressing this backlog because of their reduced performance costs and increased throughput relative to alternative assay systems. This chapter reviews the variety of existing EDC detection assays and evaluates the performance of a representative autobioluminescent estrogen-responsive EDC bioreporter to provide an overview of how autobioluminescence can be used to improve EDC detection using in vitro assay systems

Hybrid Baryons in Large-N_c QCD

We study the properties and couplings of hybrid baryons in the large-$N_c$ expansion. These are color-neutral baryon states which contain in addition to $N_c$ quarks also one constituent gluon. Hybrid baryons with both symmetric and mixed symmetric orbital wave functions are considered. We introduce a Hartree description for these states, similar to the one used by Witten for ordinary baryons. It is shown that the Hartree equations for $N_c (N_c-1)$ quarks for symmetric (mixed symmetric) states in these states coincide with those in ordinary baryons in the large-$N_c$ limit. The energy due to the gluon field is of order $\Lambda_{QCD}$. Under the assumption of color confinement, our results prove the existence of hybrid baryons made up of heavy quarks in the large $N_c$ limit and provides a justification for the constituent gluon picture of these states. The couplings of the hybrid baryons to mesons of arbitrary spin are computed in the quark model. Using constraints from the large $N_c$ scaling laws for the meson-baryon scattering amplitudes, we write down consistency conditions for the meson couplings of the hybrid baryons. These consistency conditions are solved explicitly with results in agreement with those in the quark model for the respective couplings.Comment: 20 pages and one figure, ReVTe

1/Nc1/N_c Expansion for Excited Baryons

We derive consistency conditions which constrain the possible form of the strong couplings of the excited baryons to the pions. The consistency conditions follow from requiring the pion-excited baryon scattering amplitudes to satisfy the large-N_c Witten counting rules and are analogous to consistency conditions used by Dashen, Jenkins and Manohar and others for s-wave baryons. The consistency conditions are explicitly solved, giving the most general allowed form of the strong vertices for excited baryons in the large-N_c limit. We show that the solutions to the large-N_c consistency conditions coincide with the predictions of the nonrelativistic quark model for these states, extending the results previously obtained for the s-wave baryons. The 1/N_c corrections to these predictions are studied in the quark model with arbitrary number of colors N_c.Comment: 56 pages, REVTeX; one new Appendix added containing a discussion of the results in the language of quark operator

Excited Baryons Phenomenology from Large-NcN_c QCD

We present a phenomenological analysis of the strong couplings of the negative-parity L=1 baryons from the perspective of the large-$N_c$ expansion. In the large-$N_c$ limit the mass spectrum and mixing pattern of these states are constrained in a very specific way. The mixing angles are completely determined in this limit, with predictions in good agreement with experiment. In the combined large-$N_c$ and SU(3) limits the pion couplings of the five negative-parity octets to the ground state baryons are given in terms of only 3 independent couplings. The large-$N_c$ predictions for the ratios of strong couplings are tested against experimental data.Comment: 15 pages, REVTe