Sequence and structural analysis of two designed proteins with 88% identity adopting different folds

Protein folding is a natural phenomenon by which a sequence of amino acids folds into a unique functional three-dimensional structure. Although the sequence code that governs folding remains a mystery, one can identify key inter-residue contacts responsible for a given topology. In nature, there are many pairs of proteins of a given length that share little or no sequence identity. Similarly, there are many proteins that share a common topology but lack significant evidence of homology. In order to tackle this problem, protein engineering studies have been used to determine the minimal number of amino acid residues that codes for a particular fold. In recent years, the coupling of theoretical models and experiments in the study of protein folding has resulted in providing some fruitful clues. He et al. have designed two proteins with 88% sequence identity, which adopt different folds and functions. In this work, we have systematically analysed these two proteins by performing pentapeptide search, secondary structure predictions, variation in inter-residue interactions and residue-residue pair preferences, surrounding hydrophobicity computations, conformational switching and energy computations. We conclude that the local secondary structural preference of the two designed proteins at the Nand C-terminal ends to adopt either coil or strand conformation may be a crucial factor in adopting the different folds. Early on during the process of folding, both proteins may choose different energetically favourable pathways to attain the different folds.     

Synthesis and characterization of Pt supported on multiwalled carbon nanotubes for improved catalytic performance in fuel cell applications

Journal of Porous Materials - Commercially available multiwalled carbon nanotubes (MWCNTs) were functionalized using a mixture of HNO3 and H2SO4 in refluxing condition under three different...     

Stem Cells: The Pursuit of Genomic Stability

Stem cells harbor significant potential for regenerative medicine as well as basic and clinical translational research. Prior to harnessing their reparative nature for degenerative diseases, concerns regarding their genetic integrity and mutation acquisition need to be addressed. Here we review pluripotent and multipotent stem cell response to DNA damage including differences in DNA repair kinetics, specific repair pathways (homologous recombination vs. non-homologous end joining), and apoptotic sensitivity. We also describe DNA damage and repair strategies during reprogramming and discuss potential genotoxic agents that can reduce the inherent risk for teratoma formation and mutation accumulation. Ensuring genomic stability in stem cell lines is required to achieve the quality control standards for safe clinical application.     

Screw Dislocation Assisted Spontaneous Growth of HfB2 Tubes and Rods

The mechanism of anisotropic growth of HfB₂ rods has been discussed in this study. HfB₂ powder has been synthesized via a sol–gel‐based route using phenolic resin, hafnium chloride, and boric acid as the source of carbon, hafnium, and boron respectively, though a small number of comparative experiments involved amorphous boron as the boron source. The effects of calcination dwell time and Hf:C and Hf:B molar ratio on the purity and morphology of the final powder have been studied and the mechanism of anisotropic growth of HfB₂ has been investigated. It is hypothesized that imperfect oriented attachment of finer HfB₂ particles results in screw dislocations in the coarser particles. The screw dislocation facilitates dislocation‐driven growth of particles into anisotropic HfB₂ rods.     

Nucleic acid detection strategy using gold nanoprobe of two diverse origin

In recent years, nanoparticles especially with gold and silver nanoparticles based point of care diagnostic methods is being developed for the lethal diseases like dengue. This study focused to work on the dengue virus detection in a simplest method using gold nanoparticles probe (AuNPs) with thiol tagged single strand DNA (ss‐DNA). A sensitive, fluorescence‐based detection strategy was designed to examine and quantified the hybridisation process and also elucidated the behaviour of AuNPs before and after interaction of biomolecule. The detection process was focused on aggregation of gold nanoprobe in the presence of complementary strand (target region). Hence the percentage of aggregation was measured and as a result, the limit of detection was found to be 10⁻⁶ dilutions. Current detection method was highly sensitive, easy to perform and the reaction timing is rapid between 5 and 10 min, and it can be observed through naked eye.Inspec keywords: patient diagnosis, microorganisms, nanomedicine, gold, fluorescence, nanosensors, DNA, nanoparticles, molecular biophysics, diseases, optical sensorsOther keywords: nucleic acid detection strategy, gold nanoprobe, silver nanoparticles, lethal diseases, dengue virus detection, gold nanoparticles probe, thiol tagged single strand DNA, hybridisation process, detection process, aggregation, complementary strand, current detection method, point‐of‐care diagnostic methods, fluorescence‐based detection strategy, Au     

Double metal oxide based nickel hybrid nanocatalyst for electrooxidation and alkaline fuel cell device fabrication

Dual metal oxides immobilized on amine functionalized fly ash coated conducting co-polymer composite as the catalyst supporting material has been prepared. Here, a facile method has been employed to prepare nickel nanoparticles deposited hybrid nanocomposite with unique morphology (Ni/Poly(Py-co-O-Anis)/ZnO/CuO/AFA). The resulted composite material has been characterized by different analytical techniques like scanning electron microscopy, transmission electron microscopy, X-ray diffraction, BET, EDX, elemental dot color mapping and infrared spectroscopy. Further, electrochemical performance of Ni/Poly(Py-co-O-Anis)/ZnO/CuO/AFA modified graphite electrode has been investigated for methanol and sodium sulphide electrooxidation by cyclic voltammetry, linear sweep voltammetry and chronoamperometric measurements. From electrocatalytic studies, it was found that the hybrid Ni/Poly(Py-co-O-Anis)/ZnO/CuO/AFA electrode shows superior catalytic activity compared with Ni/Poly(Py-co-O-Anis) catalyst. In addition, nanorods/nanosheets structure were obtained for hybrid composite through a simple room temperature reaction. In order to generate energy, the single stack test alkaline fuel cell has been carried out and results show the maximum power density of 103.24 and 44.75 mWcm^?2 for methanol and Na₂S, respectively. From the overall results, it has been concluded that the prepared Ni/Poly(Py-co-O-Anis)/ZnO/CuO/AFA is a potent, non-precious and low cost catalyst with an improved catalytic activity in direct alkaline fuel cells.     

Development of smart clothing for military applications using thermochromic colorants

In this study, we have developed color changeable (chameleon-type) printings on cotton fabrics using thermochromic colorants for defense applications. Different colored coatings such as light green, dark green, black, brown, and sandal have been developed using blue and orange thermochromic colorants in combination with turmeric (a natural dye) and graphite. The printed color pattern mimics jungle motif design (classic green and brown camouflage) which transforms to desert color motif on application of heat from external sources (using hot air oven or electrical power). The response time and temperature for each color change and recovery were evaluated in case of direct heating. Further, their performance was also tested by providing heat using different electrical power. The CIE L*a*b* values of the colors were measured using spectrophotometer before and after heating. The printed fabrics’ physical properties such as tensile strength, elongation at break, flexural rigidity, and tear strength were also tested before and after printing. The wash property of printed fabrics shows reasonably good fixation of colors to the fabric surface. The chameleon-type camouflage printing described in this work shows promise to use the same fabric for camouflaging at different terrains which essentially reduces the time for shifting troops to different locations.     

Detection of deoxynivalenol contamination in wheat products in Thailand

A total of ninety samples in three kinds of wheat products (30 noodle, 30 bread, and 30 cereal samples) were collected from the supermarkets in Bangkok, Thailand, from February to April 2007. The occurrence of deoxynivalenol (DON) contamination in wheat products was investigated using high-performance liquid chromatography equipped with a UV light detector. The extraction method was performed using a multifunctional cleanup column. The limit of quantification was 0.10 microg x g(-1) from the range obtained in a linear calibration. The survey found almost 94% of the DON-contaminated samples below 1 microg x g(-1), which corresponds to the U.S. Food and Drug Administration advisory level. DON was detected in 18.9% (17 of 90) of all samples, in 6.67% (2 of 30) and 16.67% (5 of 30) of noodle and bread samples at levels from 0.17 to 0.35 and 0.14 to 1.13 microg x g(-1), respectively, while it was in 33.33% (10 of 30) of cereal samples at levels from 0.13 to 0.39 microg x g(-1). The results suggest that the exposure to DON from the consumption of wheat products, especially noodles, bread, and cereal, is at a very low risk level.