Molecular phylogeny of C1 inhibitor depicts two immunoglobulin-like domains fusion in fishes and ray-finned fishes specific intron insertion after separation from zebrafish

C1 inhibitor (C1IN) is a multi-facet serine protease inhibitor in the plasma cascades, inhibiting several proteases, notably, regulates both complement and contact system activation. Despite huge advancements in the understanding of C1IN based on biochemical properties and its roles in the plasma cascades, the phylogenetic history of C1IN remains uncharacterized. To date, there is no comprehensive study illustrating the phylogenetic history of C1IN. Herein, we explored phylogenetic history of C1IN gene in vertebrates. Fishes have C1IN with two immunoglobulin like domains attached in the N-terminal region. The RCL regions of CIIN from fishes and tetrapod genomes have variations at the positions P2 and P1′. Gene structures of C1IN gene from selected ray-finned fishes varied in the Ig domain region with creation of novel intron splitting exon Im2 into Im2a and Im2b. This intron is limited to ray-finned fishes with genome size reduced below 1 Gb. Hence, we suggest that genome compaction and associated double-strand break repairs are behind this intron gain. This study reveals the evolutionary history of C1IN and confirmed that this gene remains the same locus for ∼450 MY in 52 vertebrates analysed, but it is not found in frogs and lampreys.     

Response surface methodology for lovastatin production by Aspergillus terreus GD13 strain

A wild type Aspergillus terreus GD13 strain, chosen after extensive screening, was optimized for lovastatin production using statistical Box-Behnken design of experiments. The interactive effect of four process parameters, i.e. lactose and soybean meal, inoculum size (spore concentration) and age of the spore culture, on the production of lovastatin was evaluated employing response surface methodology (RSM). The model highlighted the positive effect of soybean meal concentration and inoculum level for achieving maximal level of lovastatin (1342 mg/l). The optimal fermentation conditions improved the lovastatin titre by 7.0-folds when compared to the titres obtained under unoptimized conditions.     

Complex prokaryotic genome structure: rapid evolution of chromosome II

Although many bacteria with two chromosomes have been sequenced, the roles of such complex genome structuring are still unclear. To uncover levels of chromosome I (CI) and chromosome II (CII) sequence divergence, Mauve 2.2.0 was used to align the CI- and CII-specific sequences of bacteria with complex genome structuring in two sets of comparisons: the first set was conducted among the CI and CII of bacterial strains of the same species, while the second set was conducted among the CI and CII of species in Alphaproteobacteria that possess two chromosomes. The analyses revealed a rapid evolution of CII-specific DNA sequences compared with CI-specific sequences in a majority of organisms. In addition, levels of protein divergence between CI-specific and CII-specific genes were determined using phylogenetic analyses and confirmed the DNA alignment findings. Analysis of synonymous and nonsynonymous substitutions revealed that the structural and functional constraints on CI and CII genes are not significantly different. Also, horizontal gene transfer estimates in selected organisms demonstrated that CII in many species has acquired higher levels of horizontally transferred segments than CI. In summary, rapid evolution of CII may perform particular roles for organisms such as aiding in adapting to specialized niches.     

Solvated Crystalline Forms of Nevirapine: Thermoanalytical and Spectroscopic Studies

The study is aimed at exploring the utility of thermoanalytical methods in the solid-state characterization of various crystalline forms of nevirapine. The different forms obtained by recrystallization of nevirapine from various solvents were identified using differential scanning calorimetry and thermogravimetric analysis (TGA). The appearance of desolvation peak accompanied by weight loss in TGA indicated the formation of solvates: hemi-ethanolate (Form I), hemi-acetonitrilate (Form II), hemi-chloroformate (Form III), hemi-THF solvate (Form IV), mixed hemi-ethanolate hemi-hydrate (Form V), and hemi-toluenate (Form VI). The higher desolvation temperatures of all the solvates except toluenate than their respective boiling point indicate tighter binding of solvent. Emphasis has been laid on the determination of heat capacity and heat of solution utilizing microreaction calorimeter to further distinguish the various forms. The enthalpy of solution (ΔH _sol), an indirect measure of the lattice energy of a solid, was well correlated with the crystallinity of all the solid forms obtained. The magnitude of ΔH _sol was found to be −14.14 kJ/mol for Form I and −2.83 kJ/mol for Form V in phosphate buffer of pH 2, exhibiting maximum ease of molecular release from the lattice in Form I. The heat capacity for solvation (ΔC _p) was found to be positive, providing information about the state of solvent molecules in the host lattice. The solubility and dissolution rate of the forms were also found to be in agreement with their enthalpy of solution. Form (I), being the most exothermic, was found to be the most soluble of all the forms.     

Reduced C(beta) statistical potentials can outperform all-atom potentials in decoy identification

We developed a series of statistical potentials to recognize the native protein from decoys, particularly when using only a reduced representation in which each side chain is treated as a single C(beta) atom. Beginning with a highly successful all-atom statistical potential, the Discrete Optimized Protein Energy function (DOPE), we considered the implications of including additional information in the all-atom statistical potential and subsequently reducing to the C(beta) representation. One of the potentials includes interaction energies conditional on backbone geometries. A second potential separates sequence local from sequence nonlocal interactions and introduces a novel reference state for the sequence local interactions. The resultant potentials perform better than the original DOPE statistical potential in decoy identification. Moreover, even upon passing to a reduced C(beta) representation, these statistical potentials outscore the original (all-atom) DOPE potential in identifying native states for sets of decoys. Interestingly, the backbone-dependent statistical potential is shown to retain nearly all of the information content of the all-atom representation in the C(beta) representation. In addition, these new statistical potentials are combined with existing potentials to model hydrogen bonding, torsion energies, and solvation energies to produce even better performing potentials. The ability of the C(beta) statistical potentials to accurately represent protein interactions bodes well for computational efficiency in protein folding calculations using reduced backbone representations, while the extensions to DOPE illustrate general principles for improving knowledge-based potentials.     

Production, purification and characterization of thermostable phytase from thermophilic fungus Thermomyces lanuginosus TL-7

Ten different strains of Thermomyces lanuginosus, isolated from composting soils were found to produce phytase when grown on PSM medium. The wild type strain CM was found to produce maximum amount ofphytase (4.33 units/g DW substrate). Culturing T. lanuginosus strain CM on medium containing wheat bran and optimizing other culture conditions (carbon source, media type, nitrogen source, level of nitrogen, temperature, pH, inoculum age, inoculum level and moisture), increased the phytase yield to 13.26 units/g substrate. This culture was further subjected to UV mutagenesis for developing phytase hyperproducing mutants. The mutant (TL-7) showed 2.29-fold increase in phytase activity as compared to the parental strain. Employing Box-Behnken factor factorial design of response surface methodology resulted in optimized phytase production (32.19 units/g of substrate) by mutant TL-7. A simple two-step purification (40.75-folds) ofphytase from mutant TL-7 was achieved by anion exchange and gel filtration chromatography. The purified phytase (approximately 54 kDa) was characterized to be optimally active at pH 5.0 and temperature 70 degrees C, though the enzyme showed approximately 70% activity over a wide pH and temperature range (2.0-10.0 and 30-90 degrees C, respectively). The phytase showed broad substrate specificity with activity against sodium phytate, ADP and riboflavin phosphate. The phytase from T. lanuginosus was thermoacidstable as it showed up to 70% residual activity after exposure to 70 degrees C at pH 3.0 for 120 min. The enzyme showed Km 4.55 microM and Vmax 0.833 microM/min/mg against sodium phytate as substrate.     

Current Status of Our Understanding for Brain Integrated Functions and its Energetics

Neurochemical Research - Human/animal brain is a unique organ with substantially high metabolism but it contains no energy reserve that is the reason it requires continuous supply of O2 and energy...     

Focus: Addiction: A Feasibility Study of Bilateral Anodal Stimulation of the Prefrontal Cortex Using High-Definition Electrodes in Healthy Participants

Transcranial direct current stimulation (tDCS) studies often use one anode to increase cortical excitability in one hemisphere. However, mental processes may involve cortical regions in both hemispheres. This study’s aim was to assess the safety and possible effects on affect and working memory of tDCS using two anodes for bifrontal stimulation. A group of healthy subjects participated in two bifrontal tDCS sessions on two different days, one for real and the other for sham stimulation. They performed a working memory task and reported their affect immediately before and after each tDCS session. Relative to sham, real bifrontal stimulation did not induce significant adverse effects, reduced decrement in vigor-activity during the study session, and did not improve working memory. These preliminary findings suggest that bifrontal anodal stimulation is feasible and safe and may reduce task-related fatigue in healthy participants. Its effects on neuropsychiatric patients deserve further study.