Evaluation of Glycosyl Hydrolases in the Secretome of <Emphasis Type="Italic">Aspergillus fumigatus</Emphasis> and Saccharification of Alkali-Treated Rice Straw

A thermotolerant Aspergillus fumigatus strain isolated from composting pile of mixed industrial waste was found to produce a spectrum of cellulase and hemicellulases when cultured on rice straw solidified substrate. The two-dimensional electrophoresis (2DE) resolved the secretome into 57 distinct protein spots. The zymograms developed against 2DE gels identified the presence of three β-glucosidases and five CBHI/EGI isoforms in the secretome. The peptide mass fingerprinting of 17 protein spots by liquid chromatography mass spectrometry characterized the secretome into different glycosyl hydrolase families. The enzyme cocktail produced by A. fumigatus was capable of efficient hydrolysis of alkali pretreated rice straw (at 7% and 10% w/v) resulting in 95% and 91% saccharification, respectively.     

Simple and sensitive spectrophotometric method for determination of tricyclic antidepressant imipramine using Fe(III)-SCN<Superscript>−</Superscript> complex

A new simple procedure for the spectrophotometric determination of tricyclic antidepressant drug imipramine is proposed. The method is based on the enhancement of the colour intensity of the Fe(III)-SCN⁻ complex due to the addition of the drug imipramine. The value of molar absorptivity of the Fe(III)-SCN⁻ imipramine complex in terms of the drug lies in the range of (2.77–3.16) × 10³ L/mol cm at the absorption maximum 460 nm. The detection limit of the method was 250 μg/L. The slope, intercept, and correlation co-efficient for the present method were found to be 0.008, 0.005, and 0.998, respectively. The effect of analytical variables on the determination of the drug and the composition of the complex are discussed. The method is applicable to the determination of imipramine in the drug samples.     

A Multi-Objective Production Inventory Model with Backorder for Fuzzy Random Demand Under Flexibility and Reliability

In this paper, an Economic Production Quantity (EPQ) model is developed with flexibility and reliability consideration of production process in an imprecise and uncertain mixed environment. The model has incorporated fuzzy random demand, an imprecise production preparation time and shortage. Here, the setup cost and the reliability of the production process along with the backorder replenishment time and production run period are the decision variables. Due to fuzzy-randomness of the demand, expected average demand is a fuzzy quantity and also imprecise preparation time is represented by fuzzy number. Therefore, both are first transformed to a corresponding interval number and then using the interval arithmetic, the single objective function for expected profit over the time cycle is changed to respective multi-objective functions. Due to highly nonlinearity of the expected profit functions it is optimized using a multi-objective genetic algorithm (MOGA). The associated profit maximization problem is illustrated by numerical examples and also its sensitivity analysis is carried out.     

Drug Surfactant and Polymer Mediated Acid Catalyzed Hydrolysis of Acetohydroxamic Acid

The effects of drug-surfactant and polymer on the acid hydrolysis of acetohydroxamic acid (AHA) have been studied at room temperature in 2% (v/v) dioxane medium. Kinetic data corresponding to the reaction with drug micelles are analyzed by using the pseudo-phase ion exchange model. The binding constant and first-order rate constant in micellar media in presence of AMYTP⁺-Drug, AMYTP⁺-β-Cyclodextrine, AMYTP⁺-SDS, AMYTP⁺-PEG, AMYTP⁺-TX-100, AMYTP⁺-CTAB, have been studied in 0.5 M HCl media.     

Integrated pharmacophore and docking‐based designing of dual inhibitors of aldose reductase (ALR2) and protein tyrosine phosphatase 1B (PTP1B) as novel therapeutics for insulin‐resistant diabetes and its complications

The dual inhibitors against aldose reductase (ALR2) and protein tyrosine phosphatase 1B (PTP1B) may present an anti‐diabetic potency in insulin resistance without risks of serious diabetic complications. Therefore, in the present study, we constructed two separate pharmacophore mapping‐based 3D quantitative structure–activity relationship models for ALR2 (AADRR.1109₃ with standard deviation 0.663, 0.719, F 22.3, root‐mean‐square error 0.705, 0.647, Pearson‐r 0.802) and PTP1B (AARR.15₅ with standard deviation 0.146, 0.945, F 82.70, root‐mean‐square error 0.351, 0.621, Pearson‐r 0.831) employing the dataset of 54 flavonoids as ALR2 inhibitors and 46 naphthoquinones as PTP1B inhibitors to identify structural features necessary for the inhibition of both enzymes. These models were subsequently used as 3D query search for hierarchical virtual screening‐based designing using the PHASE database of 1.5 million compounds. Designed dual inhibitors were further subjected to GLIDE XP docking analysis using high‐resolution 3D structures of ALR2 (1US0, at resolution of 0.66 Å) and PTP1B (2F71 at resolution of 1.55 Å) available in the Protein Data Bank to authenticate identified structural features with important binding interactions necessary for dual inhibition. Copyright © 2014 John Wiley & Sons, Ltd.     

Self-assembled histidine acid phosphatase nanocapsules in ionic liquid [BMIM][BF4] as functional templates for hollow metal nanoparticles

We report the biomacromolecular self-assembly of histidine acid phosphatase (HAP), an enzyme of significant biomedical and industrial importance, in the ionic liquid (IL) 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF(4)]). The spontaneous self-assembly of HAP enzyme in [BMIM][BF(4)] results in the formation of HAP nanocapsules. The HAP enzyme molecules were found to retain their enzymatic activity after the self-assembly process, which enabled us to utilize self-assembled HAP capsules as self-catalyzing templates for the synthesis of a range of hollow metal nanoparticles (Au, Ag, Pd, and Ni) without employing any additional reducing agent. The hollow metal nanospheres with HAP encapsulated within their cavity were found to retain enzymatic activity for at least up to four cycles, as demonstrated in the case of Au-coated HAP capsules as the model system.     

Quantitative SAXS analysis of the P123/water/ethanol ternary phase diagram

The ternary phase diagram of the amphiphilic triblock copolymer PEO-PPO-PEO ((EO)(20)(PO)(70)(EO)(20) commercialized under the generic name P123), water, and ethanol has been investigated at constant temperature (T = 23 degrees C) by small-angle X-ray scattering (SAXS). The microstructure resulting from the self-assembly of the PEO-PPO-PEO block copolymer varies from micelles in solution to various types of liquid crystalline phases such as cubic, 3D hexagonal close packed spheres (HCPS), 2D hexagonal, and lamellar when the concentration of the polymer is increased. In the isotropic liquid phase, the micellar structural parameters are obtained as a function of the water-ethanol ratio and block copolymer concentration by fitting the scattering data to a model involving core-shell form factor and a hard sphere structure factor of interaction. The micellar core, the aggregation number, and the hard sphere interaction radius decrease when increasing the ethanol/water ratio in the mixed solvent. We show that the fraction of ethanol present in the core is responsible for the swelling of the PPO blocks. In the different liquid crystalline phases, structural parameters such as lattice spacing, interfacial area of PEO block, and aggregation number are also evaluated. In addition to classical phases such as lamellar, 2D hexagonal, and liquid isotropic phases, we have observed a two-phase region in which cubic Fm3m and P6(3)mmc (hexagonally close packing of spheres (HCPS)) phases coexist. This appears at 30% (w/w) of P123 in pure water and with 5% (w/w) of ethanol. At 10% (w/w) ethanol, only the HCPS phase remains present.     

Molecular organization of cholesterol in unsaturated phosphatidylethanolamines: X-ray diffraction and solid state 2H NMR reveal differences with phosphatidylcholines

The major mammalian plasma membrane lipids are phosphatidylcholines (PCs), phosphatidylethanolamines (PEs), and cholesterol. Whereas PC-cholesterol interactions are well studied, far less is known about those between PE and cholesterol. Here, we investigated the molecular organization of cholesterol in PEs that vary in their degree of acyl chain unsaturation. For heteroacid sn-1 saturated (palmitoyl), sn-2 unsaturated (various acyl chain) PEs, cholesterol solubility determined by X-ray diffraction was essentially identical with 1 (oleoyl, 51 +/- 3 mol %) and 2 (linoleoyl, 49 +/- 2 mol %) double bonds before decreasing progressively with 4 (arachidonyl, 41 +/- 3 mol %) and 6 (docosahexaenoyl, 31 +/- 3 mol %) double bonds. With 6 double bonds in each chain, cholesterol solubility was further reduced to 8.5 +/- 1 mol %. However, (2)H NMR experiments established that the orientation of cholesterol in the same heteroacid PE membranes was unaffected by the degree of acyl chain unsaturation. A tilt angle of 15 +/- 1 degrees was measured when equimolar [3alpha-(2)H(1)]cholesterol was added, regardless of the number of double bonds in the sn-2 chain. The finding that solubility of cholesterol in sn-1 saturated PEs depends on the amount of polyunsaturation in the sn-2 chain of PE differs from the equivalent PCs that universally incorporate approximately 50 mol % sterol. Unlike PCs, a differential in affinity for cholesterol and tendency to drive lateral segregation is inferred between polyunsaturated PEs. This distinction may have biological implications reflected by the health benefits of dietary polyunsaturated fatty acids that are often taken up into PE > PC.