Core histone octamers reconstituted in vitro onto DNA fragments containing the chicken β-globin gene promoter are precisely positioned with respect to the underlying DNA sequence [1]. Here we show that this is also true of the chicken β-globin gene enhancer. These nucleosome binding sites are also employed within transfected COS cell nuclei, where the chicken β-globin gene is transcriptionally inactive. Similar results were found in vivo, where positioned nucleosomes were detected over the inactive β-globin promoter in chicken brain cells and 5-day red blood cells, and over the inactive β-globin enhancer in brain cells. In contrast, the promoter and enhancer regions were found to be nucleosome-free in 15-day erythrocytes where the β-globln gene Is active. We argue that these results suggest a role for positioned nucleosomes in the regulation of the transcription of the chicken β-globin gene.
Omics is an emerging area that has many aspects in the field of science and medicine.Several exiting developments have been achieved with omics including genomics, epigenomics, transcriptomics, proteomics, metabolomics, and bioinformatics.Systems biology is another emerging scientific area to develop new approaches for investigating complex interactions within biological systems.
D-ribose-oleic acid esters were produced with or without a biocatalyst, using in the same organic media, dimethyl sulfoxide (DMSO): tert-butanol (TBU) or 2-methyl-2-butanol (2M2B). The yield of the ester product was above 90% in both of the reactions. The biocatalyst used was lipase B of Candida antarctica. Molecular characterization was performed by using all the analytical methods available: IR, 1H-NMR and 13C-NMR, HSQC, and ESI-MS.
The study assessed some of the probiotic characteristics of an isolate (AB4 26) of Lactobacillus fermentum. AB4 26 was isolated from a faecal sample of an infant, fed with breast milk. The results indicated that the isolate had acceptable survival rates in gastric juice both in the presence and absence of pepsin. It also displayed acceptable sensitivity rates to eleven different antibiotics. Hydrophobicity test showed that the isolate had a good capacity to adhere to xylene. It could also destroy sodium salts. AB4 26 displayed the least survival rates in bile salt. These initial findings could suggest that infant faeces and breast milk could serve as good sources of probiotic organisms.
Omics is an emerging area that has many aspects in the field of science and medicine.Several exiting developments have been achieved with omics including genomics, epigenomics, transcriptomics, proteomics, metabolomics, and bioinformatics.Systems biology is another emerging scientific area to develop new approaches for investigating complex interactions within biological systems.
Omics is an emerging area that has many aspects in the field of science and medicine.Several exiting developments have been achieved with omics including genomics, epigenomics, transcriptomics, proteomics, metabolomics, and bioinformatics.Systems biology is another emerging scientific area to develop new approaches for investigating complex interactions within biological systems.
Abstract Treatment of wastewater has become vital to prevent environmental pollution in recent years. Adsorption is an easily applicable, low-cost and efficient method and is the subject of this study. In this study, an adsorbent was synthesized to be used in heavy metal removal using chitosan and starch. The composite was characterized by Fourier transform infrared (FTIR) spectrophotometry, X-ray powder diffraction (XRD), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) analysis. It was determined that the composite had an amorphous and compact structure. Adsorption experiments were carried out under the optimized parameters such as solution pH, concentration, adsorbent amount, equilibrium time, and temperature. It shows that during adsorption, with the increase in pH, the adsorption efficiency and adsorption capacity first increase and then a fluctuation occurs. The highest adsorption efficiency and Q value were reached at pH 3.46 as 78% and 0.038 mol/kg, respectively. Moreover, the adsorption capacity (Q) reached its highest value with a value of 0.067 mol/kg in the presence of 30 mg adsorbent. Equilibrium experiments were validated by the Langmuir, Freundlich, Temkin and Dubinin–Radushkevich isotherm models. To investigate the adsorption mechanism, pseudo-first-order (PFO) and pseudo-second-order (PSO) kinetic models were used. It was determined that the adsorption process followed the D-R isotherm (R 2 = 0.99) and PSO (R 2 = 0.99). Therefore, the existence of chemical adsorption can be mentioned. Thermodynamic parameters enthalpy (∆H), Gibbs free energy (∆G) and entropy change (∆S) were investigated. The adsorbate-adsorbent interactions were studied by density functional theory (DFT).
To screen industrially important extracellular enzymes from the newly isolated alkalophilic bacilli and to characterize them by phenotypic and 16S-internal transcribed spacer (ITS) rDNA restriction pattern analysis.Three different environmental samples, soil, leather and horse faeces, were collected within the province of Izmir. Isolates grown on Horikoshi-I medium for 24 h at 37 degrees C were screened for extracellular enzyme activity by using eight different substrates: birchwood xylan, carboxymethylcellulose, casein, citrus pectin, polygalacturonic acid, soluble starch, and Tween 20 and 80. In total, 115 extracellular enzyme-producing bacilli were obtained. Casein was hydrolysed by 78%, soluble starch by 67%, citrus pectin by 63%, polygalacturonic acid by 62%, Tween 20 by 34%, birchwood xylan by 16%, Tween 80 by 12%, and carboxymethylcellulose by 3% of the isolates. The isolates were differentiated into 19 distinct homology groups by the 16S-ITS rDNA restriction pattern analysis.Eight different extracellular enzyme activities were determined in 115 endospore forming bacilli. The largest 16S-ITS rDNA homology group (HT1) included 36% of the isolates, 98% of which degraded casein, polygalacturonic acid, pectin and starch.This study is the first report on the characterization of the industrial enzyme-producing alkalophilic bacilli by 16S-ITS rDNA restriction fragment length polymorphism (RFLP). Restriction profiles of 64% of the isolates were found to be different from those of five reference strains used.
In this chapter we describe efficient procedures for the construction, expression and screening of comprehensive libraries of human Fab antibody fragments displayed on the surface of filamentous phage. Phagemid vectors are used for placing randomly paired light (L) and heavy (H) chain coding regions under transcriptional control of Plac. The H chain coding region is fused in-frame with the phage gene, ΔgIII, coding for a truncated version of the phage surface protein pIII (ΔpIII). After superinfection with helper phage and induction of Plac, Fd (composed of VH and CH1 domains) and κ-or α-L chains assemble into Fab fragments in the periplasm of the Escherichia coli host strain, and the Fab-ΔpIII protein complex is displayed at one end of the phage by displacing one (or more) of the wild-type pIII proteins. Enrichment of Fab phages with affinity for a selected "antigen" is then carried out by successive rounds of affinity purification using "antigen"-coated immunotubes or plastic beads followed by reinfection of E. coli cells with the eluted bound phages (see refs. , , , , , , , , , ). An outline of the method is illustrated in Fig. 1. Open image in new window Fig. 1. Overview of the steps involved in the generation of human antibody Fab libraries. Messenger RNA is isolated from peripheral blood of donors and copied into cDNA. This material is then used as template for PCR amplification of immunoglobulin gene fragments, which in turn are cloned and expressed as functional Fab molecules in fusion with a phage surface protein (pIII) as mentioned in the text. The entire mixture of phage-displayed Fab molecules are then submitted to affinity purification methods to obtain specific binders to a selected "antigen."
