SD-8, a novel therapeutic agent active against multidrug-resistant Gram positive cocci

Anti-bacterial drug resistance is one of the most critical concerns among the scientist worldwide. The novel antimicrobial decapeptide SD-8 is designed and its minimal inhibitory concentration and therapeutic index (TI) was found in the range of 1–8 μg/ml and 45–360, respectively, against major group of Gram positive pathogens (GPP). The peptide was also found to be least hemolytic at a concentration of 180 μg/ml, i.e., nearly 77 times higher than its average effective concentration. The kinetics assay showed that the killing time is 120 min for methicillin-sensitive Staphylococcus aureus (MSSA) and 90 min for methicillin-resistant S. aureus (MRSA). Membrane permeabilization is the cause of peptide antimicrobial activity as shown by the transmission electron microscopy studies. The peptide showed the anti-inflammatory property by inhibiting COX-2 with a K _D and K _i values of 2.36 × 10⁻⁹ and 4.8 × 10⁻⁸ M, respectively. The peptide was also found to be effective in vivo as derived from histopathological observations in a Staphylococcal skin infection rat model with MRSA as causative organism.     

Ethanol fermentation of mahula (<Emphasis Type="Italic">Madhuca latifolia</Emphasis>) flowers using free and immobilized bacteria <Emphasis Type="Italic">Zymomonas mobilis</Emphasis> MTCC 92

Mahula (Madhuca latifolia L.) is a deciduous tree commonly found in the tropical rain forests of Asian and Australian continent. Corolla, the edible part of its flowers, is rich in fermentable sugar (37 ± 0.23%; on dry weight basis). Batch fermentation of mahula flowers was carried out using Zymomonas mobilis MTCC 92 free cells and cells immobilized in calcium alginate matrix. The ethanol productions were 122.9 ± 0.972 and 134.6 ± 0.104 g/kg flowers on dry weight basis using free and immobilized cells, respectively, after 96 h of fermentation, which showed that cells entrapped in calcium alginate matrix yielded 8.7% more ethanol than free cells. Further, the immobilized cells were physiologically active up to three more cycles of fermentation producing 132.7 ± 0.095, 130.5 ± 0.09 and 128.7 ± 0.056 g ethanol per kg flower in first, second and third cycle, respectively.     

Inhibition of angiogenesis- and inflammation-inducing factors in human colon cancer cells <Emphasis Type="Italic">in vitro</Emphasis> and <Emphasis Type="Italic">in ovo</Emphasis> by free and nanoparticle-encapsulated redox dye,DCPIP

Background  

The redox dye, DCPIP, has recently shown to exhibit anti-melanoma activity in vitro and in vivo. On the other hand, there is increasing evidence that synthetic nanoparticles can serve as highly efficient carriers of drugs and vaccines for treatment of various diseases. These nanoparticles have shown to serve as potent tools that can increase the bioavailability of the drug/vaccine by facilitating absorption or conferring sustained and improved release. Here, we describe results on the effects of free- and nanoparticle-enclosed DCPIP as anti-angiogenesis and anti-inflammation agents in a human colon cancer HCT116 cell line in vitro, and in induced angiogenesis in ovo.     

Adenovirus stimulates choline efflux by increasing expression of organic cation transporter-2

We examined the effect of wild-type human adenovirus (Ad5) on choline transport in murine lung epithelia (MLE) and in rodent primary alveolar type II cells. Cells were active in pH-sensitive, reversible transport of choline, a process blocked pharmacologically with phenoxybenzamine, an inhibitor of organic cation transporters (OCT). PCR products for the choline transporters, OCT-1 and OCT-2, were detected, but only OCT-2 protein was robustly expressed within MLE and primary alveolar epithelial cells. Ad5 produced a two- to threefold increase in choline efflux from cells, resulting in a significant reduction in intracellular choline content and its major product, phosphatidylcholine. Effects of Ad5 on choline efflux were inhibited with phenoxybenzamine, and choline efflux was attenuated by OCT-2 small interfering RNA. Adenovirus also produced a dose-dependent increase in immunoreactive OCT-2 levels concomitant with increased cellular OCT-2 steady-state mRNA. These results indicate that adenoviruses can significantly disrupt choline trafficking in lung epithelia by upregulating expression of an alveolar protein involved in organic cation transport.     

Oxypred: Prediction and Classification of Oxygen-Binding Proteins

This study describes a method for predicting and classifying oxygen-binding pro- teins. Firstly, support vector machine (SVM) modules were developed using amino acid composition and dipeptide composition for predicting oxygen-binding pro- teins, and achieved maximum accuracy of 85.5% and 87.8%, respectively. Sec- ondly, an SVM module was developed based on amino acid composition, classify- ing the predicted oxygen-binding proteins into six classes with accuracy of 95.8%, 97.5%, 97.5%, 96.9%, 99.4%, and 96.0% for erythrocruorin, hemerythrin, hemo- cyanin, hemoglobin, leghemoglobin, and myoglobin proteins, respectively. Finally, an SVM module was developed using dipeptide composition for classifying the oxygen-binding proteins, and achieved maximum accuracy of 96.1%, 98.7%, 98.7%, 85.6%, 99.6%, and 93.3% for the above six classes, respectively. All modules were trained and tested by five-fold cross validation. Based on the above approach, a web server Oxypred was developed for predicting and classifying oxygen-binding proteins(available from http://www.imtech.res.in/raghava/oxypred/).     

Role of Oxidative Stress in <Emphasis Type="Italic">C. jejuni</Emphasis> Inactivation During Freeze-Thaw Treatment

Campylobacter jejuni represents one of the leading causes of bacterial enteritis throughout the world. Poultry is an important source of C. jejuni. Despite hygiene measures taken in the production chain, C. jejuni is frequently isolated from poultry meat. C. jejuni is a microaerophilic pathogen, affected by oxidative stress. Freeze-thaw treatment induces cell death by several mechanisms, including oxidative stress. In this article, we investigate the role of oxidative stress in C. jejuni sensitivity during and after a freeze-thaw treatment. This treatment results in dead and sublethally injured cells. The latter population might have an increased sensitivity to oxidative stress. To test this, cells were stored for another 24 h at 4°C under aerobic conditions and compared to cells that were not treated. C. jejuni survival was measured in different media (water, BHI broth, chicken juice, and chicken fillets) to test the environment protective effect. Different strains were tested, including sodB (encoding the superoxide dismutase) and cj1371 (encoding a periplasmic protein) mutants. Cell death was particularly important in water but similar in BHI, chicken juice, and chicken fillets. The sodB mutant was more sensitive to freeze-thaw treatment, suggesting that the killing mechanism involves production of superoxide anions. On the contrary, the cj1371 mutant was more sensitive to storage at 4°C, suggesting that it does not play a role in the detoxification of reactive oxygen species. Storage at 4°C after freeze-thaw treatment increases cell death of oxidative stress-sensitive populations. Sensitization to oxidative stress, freeze-thaw treatment, and further storage at 4°C could be a way to reduce C. jejuni populations on carcasses.     

Formation of interspecies fusants of <Emphasis Type="Italic">Agaricus bisporus</Emphasis> and <Emphasis Type="Italic">Agaricus bitorquis</Emphasis> mushroom by protoplast fusion

Interspecies fusants are formed between Agaricus bisporus and Agaricus bitorquis by protoplast fusion technique. Protoplasts were isolated and regenerated by using Novozyme 234 lytic enzyme. Twenty slow growing isolates were separated from the protoplast regenerated colonies, which were assumed as homokaryons (putative homokaryons). These twenty isolates were subjected to growth rate, colony morphology and spawn run studies for screening of true homokaryons. Antifungal markers were developed for selection of fusants.     

Calmodulin binds and stabilizes the regulatory enzyme, CTP: phosphocholine cytidylyltransferase

CTP:phosphocholine cytidylyltransferase (CCTalpha) is a proteolytically sensitive enzyme essential for production of phosphatidylcholine, the major phospholipid of animal cell membranes. The molecular signals that govern CCTalpha protein stability are unknown. An NH(2)-terminal PEST sequence within CCTalpha did not serve as a degradation signal for the proteinase, calpain. Calmodulin (CaM) stabilized CCTalpha from calpain proteolysis. Adenoviral gene transfer of CaM in cells protected CCTalpha, whereas CaM small interfering RNA accentuated CCTalpha degradation by calpains. CaM bound CCTalpha as revealed by fluorescence resonance energy transfer and two-hybrid analysis. Mapping and site-directed mutagenesis of CCTalpha uncovered a motif (LQERVDKVK) harboring a vital recognition site, Gln(243), whereby CaM directly binds to the enzyme. Mutagenesis of CCTalpha Gln(243) not only resulted in loss of CaM binding but also led to complete calpain resistance in vitro and in vivo. Thus, calpains and CaM both access CCTalpha using a structurally similar molecular signature that profoundly affects CCTalpha levels. These data suggest that CaM, by antagonizing calpain, serves as a novel binding partner for CCTalpha that stabilizes the enzyme under proinflammatory stress.