TMC-95A, a reversible proteasome inhibitor, induces neurite outgrowth in PC12 cells

TMC-95A has been characterized as a potent proteasome inhibitor that binds to enzymes non-covalently at low nanomolar concentrations. Herein, the neuritogenic activity of TMC-95A in PC12 rat pheochromocytoma cells is reported for the first time. TMC-95A induced a positive neurite initiation of PC12 cells at concentration ranging from 1 to 20 microM.     

Purification of filamentous bacteriophage M13 by expanded bed anion exchange chromatography

In this paper, we investigated the development of a simplified and rapid primary capture step for the recovery of M13 bacteriophage from particulate-containing feedstock. M13 bacteriophage, carrying an insert, was propagated and subsequently purified by the application of both conventional multiple steps and expanded bed anion exchange chromatography. In the conventional method, precipitation was conducted with PEG/NaCl, and centrifugation was also performed. In the single step expanded bed anion exchange adsorption, UpFront FastLine 20 (20 mm i.d.) from UpFront Chromatography was used as the contactor, while 54 ml (Ho = 15 cm) of STREAMLINE DEAE (rho = 1.2 g/cm3) from Amersham Pharmacia Biotechnology was used as the anion exchanger. The performance of the two methods were evaluated, analysed, and compared. It was demonstrated that the purification of the M13 bacteriophage, using expanded bed anion exchange adsorption, yielded the higher recovery percentage, at 82.86%. The conventional multiple step method yielded the lower recovery percentage, 36.07%. The generic application of this integrated technique has also been assessed.     

Optimal conditions for hepatitis B core antigen production in shaked flask fermentation

The effects of various environmental factors such as pH (5, 6, 7, 8 and 9), temperature (30, 37 and 40°C) and rotational speed (150, 200 and 250 rpm) on the growth and the hepatitis B core antigen (HBcAg) production ofEscherichia coli W3110IQ were examined in the present study. The highest growth rate is achieved at PH 7, 37°C and at a rotational speed of 250 rpm which is 0.927 h⁻¹. The effect of pH on cell growth is more substantial compared to other parameters; it recorded a 123% different between the highest growth rate (0.927 h⁻¹) at pH 7 and lowest growth at pH 5. The highest protein yield is achieved at pH 9, rotational speed of 250 rpm and 40°C. The yield of protein at pH 7 is 154% higher compared to the lowest yield achieved at pH 5. There is about 28% different of the protein yield for theE. coli cultivated at 250 rpm compared to that at 150 rpm which has the lowest HBcAg yield. The yield of protein at 40°C is 38% higher compared to the lowest yield achieved, at 30°C.     

Free radical theory of apoptosis and metamorphosis

Reactive oxygen species (ROS) are the major factors that induce oxidative modification of DNA and gene mutation. ROS can elicit oxidative stress and affect a wide variety of physiological and pathological processes including embryonal development, maturation and aging.     

Distinct trans-plasma membrane redox pathways reduce cell-impermeable dyes in HeLa cells

Trans-plasma membrane electron transport (tPMET) in mammalian cells has been demonstrated using artificial cell-impermeable dyes, but the extent to which reduction of these dyes involves distinct pathways remains unclear. Here we compare the properties of three commonly used dyes, WST-1, FeCN and DCIP. The presence of an intermediate electron carrier (mPMS or CoQ(1)) was obligatory for WST-1 reduction, whereas FeCN and DCIP were reduced directly. FeCN reduction was, however, greatly enhanced by CoQ(1), whereas DCIP was unaffected. Superoxide dismutase (SOD) and aminooxyacetate (AOA), a malate/aspartate shuttle inhibitor, strongly inhibited WST-1 reduction and reduced DCIP reduction by 40-60%, but failed to affect FeCN reduction, indicating involvement of mitochondrial TCA cycle-derived NADH and a possible role for superoxide in WST-1 but not FeCN reduction. Reduction of all three substrates was similarly inhibited by dicoumarol, diphenyleneiodonium and capsaicin. These results demonstrate that WST-1 FeCN and DCIP are reduced by distinct tPMET pathways.     

Histone deacetylase inhibitors potentiate TNF-related apoptosis-inducing ligand (TRAIL)-induced apoptosis in lymphoid malignancies

New therapies are required for chronic lymphocytic leukemia (CLL), an incurable disease characterized by failure of mature lymphocytes to undergo apoptosis. Activation of cell surface death receptors, such as via TRAIL receptor ligation, may provide a novel therapeutic target for various malignancies. However, CLL and other lymphoid malignancies are resistant to TRAIL. We report that low concentrations of histone deacetylase (HDAC) inhibitors, such as depsipeptide, which alone failed to induce apoptosis, markedly sensitize CLL cells and other primary lymphoid malignancies to TRAIL-induced apoptosis. These combinations caused little or no toxicity to normal lymphocytes. HDAC inhibitors sensitized resistant cells to TRAIL-induced apoptosis by facilitating formation of an active death-inducing signalling complex (DISC), leading to the rapid activation of caspase-8. The facilitated DISC formation also occurred in the absence of TRAIL-R2 upregulation. Thus, the combination of HDAC inhibitors and TRAIL may be valuable in the treatment of various hemopoietic malignancies.     

Cellware--a multi-algorithmic software for computational systems biology

The intracellular environment of a cell hosts a wide variety of enzymatic reactions, diffusion events, molecular binding, polymerization and metabolic channeling. To transform these biological events into a computational framework, distinct modeling strategies are required. While currently no tool is capable of capturing all these events, progress is being made to create an integrated environment for the modeling community. To address this niche requirement, Cellware has been developed to offer a multi-algorithmic environment for modeling and simulating both deterministic and stochastic events in the cell. AVAILABILITY: The software is available for free and can be downloaded from http://www.bii.a-star.edu.sg/sbg/cellware     

Expression patterns of dachshund during head development of Gryllus bimaculatus (cricket)

We report that Gryllus bimaculatus dachshund (Gbdac), a cricket homologue of Drosophila dachshund (Dmdac), is expressed in the developing eye and brain. During brain development, Gbdac was first expressed in the medial head region, corresponding to a part of developing protocephalic region, and expressed in the primordial and adult Kenyon cells. During eye development, Gbdac was first expressed in the lateral head region, becoming to the eye primordium and a part of the deutocerebrum. Then, Gbdac was expressed in the posterior region of the eye primordium, prior to the formation of compound eyes. The expression domain shifted to the anterior domain concomitantly with the movement of morphogenetic furrows. Gbdac was also expressed in the developing optic lobes during differentiation of the retina. These expression patterns were compared with those of Dmdac. We found that although developmental processes of the Gryllus eye and brain differ from those of the Drosophila ones, the expression patterns of Gbdac are essentially similar to those of the Dmdac.