Biosorption of Cd, Cu, Pb, and Zn from aqueous solutions by the fruiting bodies of jelly fungi (Tremella fuciformis and Auricularia polytricha)

In this study, dried and humid fruiting bodies of Tremella fuciformis and Auricularia polytricha were examined as cost-effective biosorbents in treatment of heavy metals (Cd²⁺, Cu²⁺, Pb²⁺, and Zn²⁺) in aqueous solution. The humid T. fuciformis showed the highest capacity to adsorb the four metals in the multi-metal solutions. The Pb²⁺ adsorption rates were 85.5%, 97.8%, 84.8%, and 91.0% by dried T. fuciformis, humid T. fuciformis, dried A. polytricha, and humid A. polytricha, respectively. The adsorption amount of Pb²⁺ by dried and humid T. fuciformis in Cd²⁺ + Pb²⁺, Cu²⁺ + Pb²⁺, Pb²⁺ + Zn²⁺, Cd²⁺ + Cu²⁺ + Pb²⁺, and Cd²⁺ + Zn²⁺ + Pb²⁺ solutions were not lower than that in Pb²⁺ solutions. The results suggested that in humid T. fuciformis, Cd²⁺, Cu²⁺, and Zn²⁺ promoted the Pb²⁺ adsorption by the biomass. In the multi-metal solutions of Cd²⁺ + Cu²⁺ + Pb²⁺ + Zn²⁺, the adsorption amount and rates of the metals by all the test biosorbents were in the order of Pb²⁺ > Cu²⁺ > Zn²⁺ > Cd²⁺. Compared with the pseudo first-order model, the pseudo second-order model described the adsorption kinetics much better, indicating a two-step biosorption process. The present study confirmed that fruiting bodies of the jelly fungi should be useful for the treatment of wastewater containing Cd²⁺, Cu²⁺, Pb²⁺, and Zn²⁺.     

The interaction between thymine DNA glycosylase and nuclear receptor coactivator 3 is required for the transcriptional activation of nuclear hormone receptors

The cellular counterpart of the “soluble” guanylyl cyclase found in tissue homogenates over 30 years ago is now recognized as the physiological receptor for nitric oxide (NO). The ligand-binding site is a prosthetic haem group that, when occupied by NO, induces a conformational change in the protein that propagates to the catalytic site, triggering conversion of GTP into cGMP. This review focuses on recent research that takes this basic information forward to the beginnings of a quantitative depiction of NO signal transduction, analogous to that achieved for other major transmitters. At its foundation is an explicit enzyme-linked receptor mechanism for NO-activated guanylyl cyclase that replicates all its main properties. In cells, NO signal transduction is subject to additional, activity-dependent modifications, notably through receptor desensitization and changes in the activity of cGMP-hydrolyzing phosphodiesterases. The measurement of these parameters under varying conditions in rat platelets has made it possible to formulate a cellular model of NO-cGMP signaling. The model helps explain cellular responses to NO and their modification by therapeutic agents acting on the guanylyl cyclase or phosphodiesterase limbs of the pathway.     

Proteomics analysis of plasma membrane from liver sinusoidal endothelial cells after partial hepatectomy by an improved two-dimensional electrophoresis

Liver regeneration is an angiogenesis-associated phenomenon. To identify key plasma membrane (PM) proteins of endothelial cells involved in the initiation of angiogenesis during liver regeneration, the PM of liver sinusoidal endothelial cells (LSEC) at 72 h after partial hepatectomy was enriched by an established in vivo membrane density perturbation method. The differentially expressed membrane proteins compared to those from sham operation were quantified using an improved two-dimensional 16-BAC/SDS-PAGE and identified by LC-MS/MS. Several proteins were further confirmed by cICAT labeling quantitative strategy. A total of 47 proteins were identified including known and novel proteins involved in angiogenesis or liver regeneration, such as inducible nitric oxide synthase, type IV collagen, and integrin beta3. Our results indicated that the combination of the membrane density perturbation strategy and the improved two-dimensional electrophoresis (2-DE) method are useful for investigating the endothelial dysfunctions in vivo.     

An alkali-tolerant xylanase produced by the newly isolated alkaliphilic <Emphasis Type="Italic">Bacillus pumilus</Emphasis> from paper mill effluent

An alkaline active xylanase, XynBYG, was purified from an alkaliphilic Bacillus pumilus BYG, which was newly isolated from paper mill effluent. It had an optimum pH of 8.0–9.0, and showed good stability after incubated at pH 9.0 for 120 min. The optimum temperature for the activity was 50°C, and the enzyme retained below 55% of its original activity for 30 min at 55°C. The gene coding for XynBYG consists of 687 bp and encodes 229 amino acids. Similarity analysis indicated that XynBYG belong to family 11 glycosyl hydrolases. Site-directed mutagenesis was performed to replace five sites (Tyr/Ser) to Arg/Glu and the results demonstrated that the optimum temperature of the mutant Y7 (S39R-T146E) increased 5°C and the half-life of inactivation (T1/2) at 60 and 65°C was 1 h and 25 min, respectively. Thus, it provides a potential xylanase that can meet the harsh conditions in the industrial applications.     

Inhibition of MAPK signaling by eNOS gene transfer improves ventricular remodeling after myocardial infarction through reduction of inflammation

Endothelial nitric oxide synthase (eNOS) and nitric oxide (NO) may play an important role in attenuating cardiac remodeling and apoptosis after myocardial infarction. However, the anti-inflammation effects of eNOS in infarcted myocardium and the role of MAPK signaling in eNOS/NO mediated cardiac remodeling have not yet been elucidated. Adenovirus carrying Human eNOS gene was delivered locally into heart 4 days prior to induction of myocardial infarction (MI) by left anterior descending coronary artery ligation. Monocyte/macrophage infiltration was detected by ED-1 immunohistochemistry. Western blot was employed to examine the activation of MAPK. eNOS gene transfer significantly reduced myocardial infarct size and improved cardiac contractility as well as left ventricle (LV) diastolic function at 7 days after MI. In addition, eNOS gene transfer decreased monocyte/macrophage infiltration in the infarct region of the heart. Phosphorylation of MAPK after MI were also dramatically reduced by eNOS gene transfer. All the protective effects of eNOS were blocked by N(ω)-nitro-l-arginine methyl ester (L-NAME) administration, indicating a NO-mediated event. These results demonstrate that the eNOS/NO system provides cardiac protection after MI injury through inhibition of inflammation and suppression of MAPK signaling.     

NO3/NH4 ratios affect the growth and N removal ability of Acorus calamus and Iris pseudacorus in a hydroponic system

Sweet flag (Acorus calamus L.) and yellow flag (Iris pseudacorus L.) have been used increasingly in constructed wetlands (CWs) for treatment of eutrophic wastewater. In order to properly match plant species with the type of wastewater being treated, it is important to know the performance of plant species under different NO₃⁻/NH₄⁺ ratios. We investigated dry matter (DW) production and N content of A. calamus and I. pseudacorus under five NO₃⁻/NH₄⁺ ratios (100/0, 75/25, 50/50, 25/75, and 0/100) in a hydroponic system. Results showed that the two species exhibited different preferences for NO₃⁻ and NH₄⁺. Total DW, shoot DW, and N content were greater with NO₃⁻/NH₄⁺ ratios of 50/50 and 75/25 than otherwise for A. calamus, but these parameters were only higher under the sole NO₃⁻ treatment in I. pseudacorus. We conclude that A. calamus could be best used for treating wastewater in constructed wetlands with NO₃⁻/NH₄⁺ ratios between 50/50 and 75/25, while I. pseudacorus for treating wastewater with NO₃⁻ only to achieve the highest biomass production and efficiency in the removal of N.     

Limits to sustainable energy budget during lactation in the striped hamster (Cricetulus barabensis) raising litters of different size

A female animal appears to approach an upper limit to the rate of sustained energy intake/metabolic rate (SusEI/MR) during lactation. However, different species of animals may respond differently to the sustainable limit. Here, we measured energy budget during lactation in female striped hamsters raising litters of natural size (Con), and females whose litter size was manipulated during early lactation to support fewer or more pups (minus pups, MP or plus pups, PP). The striped hamsters significantly decreased their body mass and increased food intake from early to late lactation; and MP females had lower weight loss and food intake than the control and PP females. Litter size of the PP group decreased significantly over the period of lactation, and pups were weaned at a similar weight to that of the controls. MP females supported a significantly lower litter mass throughout lactation compared with the control and PP females, but during late lactation the pups from the MP group were significantly heavier. Resting metabolic rate (RMR) did not differ significantly between the three groups and the gross energy intake during peak lactation was 5.0×, 4.2× and 5.0 × RMR for the control, MP and PP females, respectively. Female striped hamsters reached a plateau in food intake at around 14 g/d during peak lactation, which might signify a limit of SusEI at 5.0 × RMR. However, it was not possible to determine whether the limitation on SusEI was imposed centrally by the capacity of the gastrointestinal tract to process food, peripherally by the capacity of the mammary gland to produce milk, or by the capacity of animals to dissipate heat.     

Osmolytes modulate conformational exchange in solvent‐exposed regions of membrane proteins

Site‐directed spin labeling (SDSL) was used to investigate local structure and conformational exchange in two bacterial outer‐membrane TonB‐dependent transporters, BtuB and FecA. Protecting osmolytes, such as polyethylene glycols (PEGs) are known to modulate a substrate‐dependent conformational equilibrium in the energy coupling motif (Ton box) of BtuB. Here, we demonstrate that a segment that is N‐terminal to the Ton box in BtuB, is in conformational exchange between ordered and disordered states with or without substrate. Protecting osmolytes shift this equilibrium to favor the more ordered, folded state. However, a segment of BtuB that is C‐terminal to the Ton box that is not solvent exposed is insensitive to PEGs. Protecting osmolytes also modulate a conformational equilibrium in the Ton box of FecA, with larger molecular weight PEGs producing the largest shifts in the conformational free energy. These data indicate that solvent‐exposed regions of these transporters undergo conformational exchange and that regions of these transporters that are involved in protein–protein interactions sample multiple conformational substates. The sensitivity to solute provides an explanation for differences seen between two high‐resolution structures of BtuB, which each likely represent one conformation from a subset of states that are normally sampled by the protein. This work also illustrates how SDSL and osmolytes may be used to characterize and quantitate conformational equilibria in membrane proteins.