<Emphasis Type="Italic">In vitro</Emphasis> regenerating plantlets in <Emphasis Type="Italic">Pandanus amaryllifolius</Emphasis> Roxb. as a model system to study the development of lower epidermal papillae

Pandanus amaryllifolius Roxb. has been identified as a rich source of principal basmati aroma compound 2 acetyl-1-pyrroline (2AP). An easy and efficient protocol for clonal propagation of P. amaryllifolius Roxb. using lateral buds as an explant has been developed and the in vitro-raised seedlings were used to study the lower epidermal papillae development. The principal aroma compound 2AP along with other aroma compounds are stored in the lower epidermis papillae of leaf. The developmental pattern of these papillae was traced out using scanning electron microscopy. It was observed that stomata act as the site of initiation for development of the papillae followed by their lateral spread across the epidermal cells. During development, the first papillae bulged out as a protrusion of the lower epidermis that further metamorphosed into well-grown papillae. These developments are well-correlated with 2AP contents, in which the in vitro-raised seedlings had less 2AP contents (66.99 ppb) than the mother plant (96.88 ppb).     

Molecular dynamics study of thrombin capture by aptamers TBA26 and TBA29 coupled to a DNA origami

The fabrication of DNA origamis is one of the very few possibilities to create nanostructures with precise atomistic-tailored geometries in a variety of shapes. In addition, these origamis can be functionalized or be impregnated with specialised aptamers in order to convert them into nanosensors or to tune them with pre-specified properties simply by impregnating single-stranded DNA or RNA chains (aptamers) via the precise features of DNA pairing. We performed molecular dynamics simulations to determine the relative energetics associated with the capture of thrombin by two aptamers TBA26 and TBA29 attached to a rectangular DNA origami. The molecular simulations provided detailed structural information of aptamer–enzyme interactions which are crucial for the efficient design of aptamer-based biosensors. In addition, the simulations showed a remarkable selectivity of the biosensor assembly for thrombin. The detection, capture, and sensing of enzymes is of great significance in biomedicine. In particular, the detection of thrombin is a major task in cardiovascular diagnostics and therapeutics. On the other hand, our simulations can be extended to detect biotoxins or any other chemical or biological agent by simply choosing proper aptamers. Finally, the problems due to the large number of atoms involved as well as the quality of the approximations are also discussed.     

HSPB5 (αB-crystallin) confers protection against paraquat-induced oxidative stress at the organismal level in a tissue-dependent manner

Oxidative stress is one of the major and continuous stresses, an organism encounters during its lifetime. Tissues such as the brain, liver and muscles are more prone to damage by oxidative stress due to their metabolic activity, differences in physiological and adaptive processes. One of the defence mechanisms against continuous oxidative stress is a set of small heat shock proteins. αB-Crystallin/HSPB5, a small heat shock protein, gets upregulated under stress and acts as a molecular chaperone. In addition to acting as a molecular chaperone, HSPB5 is shown to have a role in other cytoprotective functions such as inhibition of apoptosis, prevention of oxidative stress and stabilisation of cytoskeletal system. Such protection in vivo, at the organism level, particularly in a tissue-dependent manner, has not been investigated. We have expressed HSPB5 in fat body (liver), neurons and specifically in dopaminergic and motor neurons in Drosophila and investigated its protective effect against paraquat-induced oxidative stress. We observed that expression of HSPB5 in neurons and fat body confers protection against paraquat-induced oxidative stress. Expression in dopaminergic neurons showed a higher protective effect. Our results clearly establish the protective ability of HSPB5 in vivo; the extent of protection, however, varies depending on the tissue in which it is expressed. Interestingly, neuronal expression of HSPB5 resulted in an improvement in negative geotropic behaviour, whereas specific expression in muscle tissue did not show such a beneficial effect.     

An Efficient and Epimerization Free Synthesis of C-Terminal Arylamides Derived from α-Amino Acids and Peptide Acids via T3P Activation

A high yield and rapid synthesis of enantiomerically pure N ^α -protected amino/peptide acid arylamides using n-propylphosphonic anhydride (T3P) in presence of N-methylmorpholine is described. The generality of the reaction has been studied for various N ^α -protected amino acids with diverse range of aromatic amines and coumarin derivatives.     

Detergent-compatible,organic solvent-tolerant alkaline protease from Bacillus circulans MTCC 7942: Purification and characterization

Proteases are now recognized as the most indispensable industrial biocatalyst owing to their diverse microbial sources and innovative applications. In the present investigation, a thermostable, organic solvent-tolerant, alkaline serine protease from Bacillus circulans MTCC 7942, was purified and characterized. The protease was purified to 37-fold by a three-step purification scheme with 39% recovery. The optimum pH and temperature for protease was 10 and 60°C, respectively. The apparent molecular mass of the purified enzyme was 43 kD as revealed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The K_m and V_max values using casein-substrate were 3.1 mg/mL and 1.8 µmol/min, respectively. The protease remained stable in the presence of organic solvents with higher (>3.2) log P value (cyclohexane, n-octane, n-hexadecane, n-decane, and n-dodecane), as compared to organic solvents with lower (<3.2) log P value (acetone, butanol, benzene, chloroform, toluene). Remarkably, the protease showed profound stability even in the presence of organic solvents with less log P values (glycerol, dimethyl sulfate [DMSO], p-xylene), indicating the possibility of nonaqueous enzymatic applications. Also, protease activity was improved in the presence of metal ions (Ca²⁺, Mg²⁺, Mn²⁺); enhanced by biosurfactants; hardly affected by bleaching agents, oxidizing agents, and chemical surfactants; and stable in commercial detergents. In addition, a protease–detergent formulation effectively washed out egg and blood stains as compared to detergent alone. The protease was suitable for various commercial applications like processing of gelatinous film and as a compatible additive to detergent formulation with its operative utility in hard water.     

Gibberellic Acid Induces Unique Molecular Responses in ‘Thompson Seedless’ Grapes as Revealed by Non-targeted Metabolomics

Journal of Plant Growth Regulation - Compact clusters and small berry size are the major problems associated with the commercialization of table grapes. The application of gibberellic acid 3 (GA3)...