Reverse micelle induced flipping of binding site and efficiency of albumin protein with an ionic styryl dye.

The effect of reverse micelle environment on the binding mechanism of 2-(4-(dimethylamino)styryl)-1-methylpyridinium iodide (DASPMI) with Bovine Serum Albumin (BSA) compared with that in buffer solution has been investigated in this paper with the help of steady state and time-resolved emission spectroscopy along with molecular docking to have a correct picture about binding. The binding of DASPMI with attachment efficiency of 30% and 70% at site I (subdomain IIA) and site II (subdomain IIIA) of BSA, respectively, in buffer solution gets reversed inside a reverse micelle. The bigger cavity size of site II in buffer solution ushers the dye with increased attachment efficiency and in reverse micelle change in pi-stacking and hydrophobic interaction control the attachment efficiency.

Polar tagging in the synthesis of monodisperse oligo(p-phenyleneethynylene)s and an update on the synthesis of oligoPPEs.

One important access to monodisperse (functionalized) oligoPPEs is based on the orthogonality of the alkyne protecting groups triisopropylsilyl and hydroxymethyl (HOM) and on the polar tagging with the hydroxymethyl moiety for an easy chromatographic separation of the products. This paper provides an update of this synthetic route. For the deprotection of HOM protected alkynes, γ-MnO₂ proved to be better than (highly) activated MnO₂.

Influence of surfactants on the excited state photophysics of 4-nitro-1-hydroxy-2-naphthoic acid.

This paper reports the changed dynamics of excited state proton transfer (ESPT) photophysics of 4-nitro-1-hydroxy-2-naphthoic acid (NHNA) in ionic and nonionic micelles, as revealed from time-resolved emission spectra (TRES) and time-resolved area normalized emission spectra (TRANES). Both the neutral and anionic bands of NHNA are enhanced and blue-shifted inside the micelles. Quenching of emission by metal Cu(2+) reveals that NHNA does not penetrate into the core of the micelles; rather it binds to the micelle/water interfacial region.

MiDReG: a method of mining developmentally regulated genes using Boolean implications.

We present a method termed mining developmentally regulated genes (MiDReG) to predict genes whose expression is either activated or repressed as precursor cells differentiate. MiDReG does not require gene expression data from intermediate stages of development. MiDReG is based on the gene expression patterns between the initial and terminal stages of the differentiation pathway, coupled with "if-then" rules (Boolean implications) mined from large-scale microarray databases.

Extracellular hydrophobic regions in scavenger receptor BI play a key role in mediating HDL-cholesterol transport.

The binding of high density lipoprotein (HDL) to scavenger receptor BI (SR-BI) is responsible for whole-body cholesterol disposal via reverse cholesterol transport. The extracellular domain of SR-BI is required for HDL binding and selective uptake of HDL-cholesterol. We identified six highly hydrophobic regions in this domain that may be important for receptor activity and performed site-directed mutagenesis to investigate the importance of these regions in SR-BI-mediated cholesterol transport.

Molecular mechanism of polyethylene glycol mediated stabilization of protein.

The effect of different molar ratios of polyethylene glycol (PEG) on the conformational stability of protein, bovine serum albumin (BSA), was studied. The binding of PEG with BSA was observed by fluorescence spectroscopy by measuring the fluorescence intensity after displacement of PEG with chromophore ANS and had further been confirmed by measuring the intrinsic fluorescence of tryptophan residues of BSA. Co-lyophilization of BSA with PEG at optimum BSA:PEG molar ratio led to the formation of the stable protein particles.

Quest for mode of binding of 2-(4-(dimethylamino)styryl)-1-methylpyridinium iodide with calf thymus DNA.

The mode of binding of 2-(4-(dimethylamino)styryl)-1-methylpyridinium iodide (DASPMI) with calf thymus DNA as revealed from different steady state and time-resolved emission spectroscopic measurements has been reported in this paper. Fluorescence enhancement of DASPMI and its quenching by potassium iodide (KI) points to groove binding of dye with ct-DNA, rather than intercalation in the ct-DNA helix. An increase in steady state anisotropy and fluorescence lifetime hints at binding with ct-DNA.

Thiol redox status critically influences mitochondrial response to thyroid hormone-induced hepatic oxidative injury: A temporal analysis.

Liver is a major target organ for thyroid hormone. The objective of the present study was to investigate temporal regulation of mitochondrial glutathione and protein-bound thiol redox status in hyperthyroid liver. Mitochondria were isolated from control and hyperthyroid rat liver tissues at different time intervals, i.

High-throughput intermittent-contact scanning probe microscopy.

Large arrays of micro-cantilevers operating in parallel are essential for achieving high throughput in such applications as life sciences, nanofabrication and semiconductor metrology. A novel intermittent-contact mode operation is presented that is suitable for such applications. The cantilevers are electrostatically actuated.

Ly6d marks the earliest stage of B-cell specification and identifies the branchpoint between B-cell and T-cell development.

Common lymphoid progenitors (CLPs) clonally produce both B- and T-cell lineages, but have little myeloid potential in vivo. However, some studies claim that the upstream lymphoid-primed multipotent progenitor (LMPP) is the thymic seeding population, and suggest that CLPs are primarily B-cell-restricted. To identify surface proteins that distinguish functional CLPs from B-cell progenitors, we used a new computational method of Mining Developmentally Regulated Genes (MiDReG).

On the spectral behavior of an ionic styryl dye: effect of micelle-polyethylene-block-polyethylene glycol diblock copolymer assembly.

The interaction of anionic micelle sodium dodecyl sulfate (SDS) and amphiphilic block copolymers polyethylene-b-polyethylene glycol (PE-b-PEG) and the sharp change of excited-state charge-transfer complex photophysics of 2-(4-(dimethylamino)styryl)-1-methylpyridinium iodide (DASPMI) inside of the supramolecular assembly have been addressed in the paper. The dramatic enhancement of emission intensity of DASPMI incorporated inside of the nanostructure formed by micellar and polymeric chains indicates a completely different environment compared to that in the water and micellar system. A huge increase in the rotational relaxation time obtained from time-resolved anisotropy decay and the value of the order parameter is indicative of a very restrictive regime in the self-assembly system.

Dye-surfactant interaction: modulation of photophysics of an ionic styryl dye.

The interesting modulation of multibond rotation-induced intramolecular charge transfer photophysics of 2-(4-(dimethylamino) styryl)-1-methylpyridinium iodide in different micelles due to different contributions of twisted intramolecular charge transfer (TICT) and hydrogen bonding deactivation channels have been reported in this paper. 2-(4-(dimethylamino) styryl)-1-methylpyridinium iodide enters into all the micelles in different positions from the water solution due to active hydrophobic force and electrostatic field, as revealed from the shift and intensity of intramolecular charge transfer (ICT) band. The presence of mechanically trapped water with the addition of salt and inherent thermodynamic water controls the ICT emission.

An alternative method of promoter assessment by confocal laser scanning microscopy.

A rapid and useful method of promoter activity analysis using techniques of confocal laser scanning microscopy (CLSM) is described in the present study. The activities of some pararetroviral promoters such as CaMV35S (Cauliflower mosaic virus), FMVSgt3 (Figwort mosaic virus sub-genomic transcript) and MMVFLt12 (Mirabilis mosaic virus full-length transcript) coupled to GFP (green fluorescent protein) and GUS (beta-glucuronidase) reporter genes were determined simultaneously by the CLSM technique and other available conventional methods for reporter gene assay based on relevant biochemical and molecular approaches. Consistent and comparable results obtained by CLSM as well as by other conventional assay methods confirm the effectiveness of the CLSM approach for assessment of promoter activity.

Enhanced production of recombinant streptokinase in Escherichia coli using fed-batch culture.

Fed-batch culture strategy is often used for increasing production of heterologous recombinant proteins in Escherichia coli. This study was initiated to investigate the effects of dissolved oxygen concentration (DOC), complex nitrogen sources and pH control agents on cell growth and intracellular expression of streptokinase (SK) in recombinant E. coli BL21(DE3).

Immobilized metal affinity chromatography in open-loop simulated moving bed technology: purification of a heat stable histidine tagged beta-glucosidase.

Open-loop simulated moving bed (SMB) has been used for immobilized metal affinity chromatographic (IMAC) purification of his-tagged beta-glucosidase expressed in E. coli. A simplified approach based on an optimized single column protocol is used to design the open-loop SMB.

Rat testicular mitochondrial antioxidant defence system and its modulation by aging.

Accumulation of oxidative damage caused by reactive oxygen species (ROS) underlies fundamental changes found during aging. In the present study, age related effect on testicular mitochondrial oxidant generation and antioxidant defence profile was investigated in Wistar rats at 3 months (young adults), 12 months (old adults) and 24 months (senescent animals) of age. Mitochondrial oxidative stress parameters viz.

Cytosine arabinoside-induced cytogenotoxicity in bone marrow and spermatogonial cells of mice and its potential transmission through the male germline.

Cytosine arabinoside (Ara-C), a widely prescribed antineoplastic drug, especially for the treatment of acute myeloid leukaemia, is a pyrimidine analog, in which the ribose sugar of cytidine is replaced by arabinose moiety. Ara-C reportedly competes with dCTP for incorporation into DNA during synthesis and exhibits various cytogenotoxic effects. In the present study, single intraperitoneal treatment of three different doses of Ara-C, 100, 150 and 200 mg/kg b.

Bronchogenic carcinoma after lung transplantation: characteristics and outcomes.

Background: Lung cancer may occur in the lung transplant population because many patients are former smokers. Not much is known about risk factors and outcomes in these patients.

Methods: We performed a search of the lung transplant database at our institution to identify patients who had been diagnosed with lung cancer.

Boolean implication networks derived from large scale, whole genome microarray datasets.

We describe a method for extracting Boolean implications (if-then relationships) in very large amounts of gene expression microarray data. A meta-analysis of data from thousands of microarrays for humans, mice, and fruit flies finds millions of implication relationships between genes that would be missed by other methods. These relationships capture gender differences, tissue differences, development, and differentiation.

Temporal changes in gene expression induced by sulforaphane in human prostate cancer cells.

Background: Prostate cancer is thought to arise as a result of oxidative stresses and induction of antioxidant electrophile defense (phase 2) enzymes has been proposed as a prostate cancer prevention strategy. The isothiocyanate sulforaphane, derived from cruciferous vegetables like broccoli, potently induces surrogate markers of phase 2 enzyme activity in prostate cells in vitro and in vivo. To better understand the temporal effects of sulforaphane and broccoli sprouts on gene expression in prostate cells, we carried out comprehensive transcriptome analysis using cDNA microarrays.

Orientational dynamics of a charge transfer complex in cyclodextrin cavity as receptor.

This paper reports the structure and dynamics of a twisted intermolecular charge transfer molecule 2-(4-(dimethylamino) styryl)-1-methylpyridinium iodide (o-DASPMI) included inside alpha-, beta- and gamma-cyclodextrin, investigated by using steady state and time-resolved emission spectroscopy and also theoretical modeling. A nice 1 : 1 inclusion complex with beta-CD in the excited state could be found with the dimethylamino group of the molecule sticking out as revealed from steady state and time-resolved emission. The inclusion complex has a longer decay time compared to that in neat water.

Isolation of potato proteins using simulated moving bed technology.

The simulated moving bed (SMB) concept of chromatography was applied to treat potato juice from production of starch. The aim was to harvest proteins. SMB offers possibilities to operate with different process strategies and in this study it was shown possible to harvest up to 80% of the protein in a process utilizing very little extra water besides that already present in the juice.

Genotypic and phenotypic diversity of Anabaena isolates from diverse rice agro-ecologies of India.

The genus Anabaena is one of the commonly observed genera in the rice fields in South-east Asia. Diversity analyses of a set of 70 Anabaena strains (including 67 strains isolated from diverse rice agro ecologies of India, and three International Reference/Type strains), was carried out using morphological and molecular datasets. The pattern of growth in liquid and solid medium and microscopic observations revealed tremendous diversity in the Anabaena germplasm analysed.