Redox active molecules cytochrome c and vitamin C enhance heme-enzyme peroxidations by serving as non-specific agents for redox relay

We report that incorporation of very low concentrations of redox protein cytochrome c and redox active small molecule vitamin C impacted the outcome of one-electron oxidations mediated by structurally distinct plant/fungal heme peroxidases. Evidence suggests that cytochrome c and vitamin C function as a redox relay for diffusible reduced oxygen species in the reaction system, without invoking specific or affinity-based molecular interactions for electron transfers. The findings provide novel perspectives to understanding - (1) the promiscuous role of cytochrome b(5) in the metabolism mediated by liver microsomal xenobiotic metabolizing systems and (2) the roles of antioxidant molecules in affording relief from oxidative stress.     

Effects of arsenite stress on growth and proteome of Klebsiella pneumoniae

In the present study an arsenite, As(III), tolerating bacterium, MR4, was isolated from Mulla River Pune, India, capable of reducing arsenate to arsenite and identified as Klebsiella pneumoniae (HQ857583). Comparative proteomic analysis using two-dimensional gel electrophoresis (2-DGE) and matrix assisted laser desorption ionization-time of flight-time of flight (MALDI-TOF/TOF) was used to monitor the proteins undergoing changes in expression levels under 2.5 mM As(III) stress. The 2-DGE proteome map has shown that 60 proteins were differentially expressed under As(III) stress, of which 39 proteins were successfully identified with a MASCOT score greater than 70 (p<0.05). Among the identified proteins, membrane transport/binding proteins, porins, and amino acid metabolism enzymes were down-regulated while stress responsive proteins and antioxidant enzymes were up-regulated. Proteins involved in carbohydrate metabolism, particularly those in pentose phosphate pathway were also up-regulated while those involved in pyruvate metabolism were down-regulated. However, proteins involved in glycolysis and tricarboxylic acid cycle showed a mixed regulation response. These findings provide new insights into the probable mechanisms by which K. pneumoniae (HQ857583) could be adapting to As(III) stress.     

Color Assortative Mating in a Mainland Population of the Poison Frog Oophaga pumilio

Assortative mating is a reproductive strategy used by a diversity of animals, in which individuals choose a mate that shares similar characteristics. This mating strategy has the potential to promote the evolution of various sexual signals and has been a proposed mechanism driving and maintaining color variation in the anuran family Dendrobatidae. Most studies have examined this reproductive strategy in the polytypic poison frog, Oophaga pumilio, in the Bocas del Toro archipelago in Panama. Little attention, however, has been given to ancestral populations across this species’ mainland range, where dramatic color polytypism appears to lack. Additionally, most studies are exclusively experimental and investigate mate choice between allopatric populations, neglecting the behaviors of naturally occurring mates. This study observed natural mating pairs within a population of O. pumilio on mainland Costa Rica and tested the prediction that color phenotype of mating females and males would be correlated. Naturally occurring pairs were found to share similar coloration, suggesting that color assortative mating operates in nature, and in a mainland population. Our results indicate that coloration is an important trait in driving the natural mate choices of female O. pumilio, which provides valuable insight into realistic mate selection tactics of this dendrobatid frog.     

Nanotechnology based anti‐infectives to fight microbial intrusions

With the rise in human population across the globe especially in developing countries, the incidence of microbial infections are increasing with greater pace. On the other hand, available medication and therapies are found to be insufficient for the complete cure of such microbial infections due to the development of resistance against various antibiotics. Therefore, to cope up the menace of microbial infections and drug resistance, there is demand for new and compelling technology, which has the ability to impede these problems. Many research groups worldwide are finding a ray of hope in nanomaterials owing to their unique properties. In the present review we have discussed the reasons behind the development of new materials based on nanotechnology. It is mainly focused on pioneering studies on application of nanomaterials like carbon nanotube, fullerene, dendrimers, nanocomposite and metal nanoparticles in combating dreadful pathogens. Moreover, the concerns about their toxicity have also been discussed.     

Evidence for the existence of an intracellular root-lectin in soybeans

Soybean (Glycine max (L.) Merr.) root lectin, identified as extractable agglutination activity, was shown to reappear following 15-h incubations of roots that had previously been stripped of all extractable lectin activity. Additional lectin activity was released following disruption of the root tissues and cellular fractionation. These lectin activities were shown to have binding specificity an antibody cross-ractivity similar to soybean seed and root lectins previously described. Thus, it is possible that this intracellular lectin represents the source of extracellular root lectins.     

Characterization of the proteins of bacterial strain isolated from contaminated site involved in heavy metal resistance--a proteomic approach

The present study describes response of a bacterial strain isolated from a polluted river to heavy metal toxicity. The bacterium was identified to be Klebsiella pneumoniae by biochemical tests using API 20E strips and 16S ribotyping. The isolate was studied for its tolerance to two heavy metals, i.e., cobalt (Co(2+)) and lead (Pb(2+)) by growing it in citrate mineral medium (CMM). Proteomic approach involving two-dimensional polyacrylamide gel electrophoresis (2D PAGE) and mass spectrometry (MS) was used to identify the differentially expressed proteins under heavy metal stress. Two of the differentially expressed proteins were identified to be l-isoaspartate protein carboxymethyltransferase type II and DNA gyrase A. To our knowledge, this is for the first time that K. pneumoniae has been reported to be present in metal contaminated site and l-isoaspartate protein carboxymethyltransferase type II protein to be over expressed under heavy metal stress. The role of these proteins in metal tolerance is discussed.     

Deep Sequencing Reveals Highly Variable Gut Microbial Composition of Invasive Fish Mossambicus Tilapia (<Emphasis Type="Italic">Oreochromis mossambicus</Emphasis>) Collected from Two Different Habitats

Tilapia ( Oreochromis mossambicus ) is one of the most invasive fish found throughout the World and emerged as a major threat to the indigenous fishes in many countries. Investigating the gut microbial diversity of such fishes is one of the ways to understand its physiology. In the present study, we have explored the gut microbial community structure of tilapia using 16S rRNA gene sequencing on the Illumina Miseq platform. Our study showed significant differences in tilapia gut microbiota collected from different habitats (i.e. river and lakes) suggesting the influence of habitat on the gut microbial diversity of tilapia. This study gives a first insight into the mossambicus tilapia gut microbiota and provides a reference for future studies.     

Plant seed lectins disrupt growth of germinating fungal spores

Plant seed lectins are well-characterized proteins and glycoproteins whose natural function remains unknown. We found that eleven purified seed lectins (representing five groups of lectin sugar specificities) bound to the germ tubes of asexual spores of Neurospora crassa, Aspergillus amstelodami , and Botryodiplodia theobromae. The lectins caused several types of quantifiable growth disruption during germination of these seed- or soil-borne fungal spores, including sensitivity to osmotic lysis, adventitious branching of the spore germ tubes, and inhibition of germ tube elongation. These anti-fungal effects of purified lectins, which were reversible with the sugar hapten specific for each lectin, were partially duplicated by lectin-like factors in the homologous crude seed extracts. The seed lectins may disrupt fungal growth by interfering with normal cell wall deposition and assembly.     

In vivo parameter identification in arteries considering multiple levels of smooth muscle activity

In this paper an existing in vivo parameter identification method for arteries is extended to account for smooth muscle activity. Within this method a continuum-mechanical model, whose parameters relate to the mechanical properties of the artery, is fit to clinical data by solving a minimization problem. Including smooth muscle activity in the model increases the number of parameters. This may lead to overparameterization, implying that several parameter combinations solve the minimization problem equally well and it is therefore not possible to determine which set of parameters represents the mechanical properties of the artery best. To prevent overparameterization the model is fit to clinical data measured at different levels of smooth muscle activity. Three conditions are considered for the human abdominal aorta: basal during rest; constricted, induced by lower-body negative pressure; and dilated, induced by physical exercise. By fitting the model to these three arterial conditions simultaneously a unique set of model parameters is identified and the model prediction agrees well with the clinical data.