Low Molecular Mass Fraction Research Articles

Novel eco-friendly green inhibitor of corrosion based on acerola (Malpighia glabra) waste aqueous extract for mild steel in 1 mol L–1 HCl solution

This study studied the effectiveness of a sustainable corrosion inhibitor derived from acerola peels and seeds (an industrial waste) applied to a mild steel substrate (acerola aqueous extract - AAE). Surface analysis, gravimetric, and electrochemical tests evaluated the corrosion inhibitory action. Results demonstrate that the acerola waste aqueous extract shows a good inhibition efficiency acting through chemical adsorption onto mild steel. The aqueous extract demonstrated a maximum inhibition efficiency of 92.0% at 8000 ppm after 2 h of immersion and around 96% from 1000 ppm from 6 to 96 h of immersion. High and low molecular mass fractions (HMMF and LMMF) obtained from the acerola waste aqueous extract (cutoff 3kDa) were evaluated and compared to the crude extract. After 2 h immersion at a concentration of 1000 ppm, the crude extract showed 83.8% inhibition efficiency, while HMMF and LMMF showed 88.0% and 78.5%, respectively, suggesting that components from both fractions participate in the inhibition process, showing that in the studied extract several molecules may be responsible for the inhibitory efficiency of the extract. XPS analysis and biochemical characterization of the crude extract showed that the proteins are strong candidates to play a role in the inhibition process through the N-Fe chemical bond, corroborating the activation energy studies. These results show an excellent alternative for using acerola peel and seed as corrosion inhibitors.

Identification and Characterization of Novel ACE Inhibitory and Antioxidant Peptides from Sardina pilchardus Hydrolysate.

Sardina pilchardus is a valuable source of bioactive peptides with potential applications in functional foods. In this study, we investigated the angiotensin-converting enzyme (ACE) inhibitory activity of Sardina pilchardus protein hydrolysate (SPH) produced using dispase and alkaline protease. Our results showed that the low molecular mass fractions (<3 kDa) obtained through ultrafiltration exhibited more effective ACE inhibition, as indicated by screening with ACE inhibitory activity. We further identified the low molecular mass fractions (<3 kDa) using an LC-MS/MS rapid screening strategy. A total of 37 peptides with potential ACE inhibitory activity were identified based on high biological activity scores, non-toxicity, good solubility, and novelty. Molecular docking was used to screen for peptides with ACE inhibitory activity, resulting in the identification of 11 peptides with higher -CDOCKER ENERGY and -CDOCKER INTERACTION ENERGY scores than lisinopril. The sequences FIGR, FILR, FQRL, FRAL, KFL, and KLF were obtained by synthesizing and validating these 11 peptides in vitro, all of which had ACE inhibitory activity, as well as zinc-chelating capacity. All six peptides were found to bind to the three active pockets (S1, S2, and S1') of ACE during molecular docking, indicating that their inhibition patterns were competitive. Further analysis of the structural characteristics of these peptides indicated that all six peptides contain phenylalanine, which suggests that they may possess antioxidant activities. After experimental verification, it was found that all six of these peptides have antioxidant activities, and we also found that the SPH and ultrafiltration fractions of SPH had antioxidant activities. These findings suggest that Sardina pilchardus may be a potential source of natural antioxidants and ACE inhibitors for the development of functional foods, and using LC-MS/MS in combination with an online database and molecular docking represents a promising, effective, and accurate approach for the discovery of novel ACE inhibitory peptides.

Bioactive properties of peptide fractions from Brazilian soy protein hydrolysates: In silico evaluation and experimental evidence

Soybeans are a known source of dietary proteins and potential bioactive peptides. In this study, a protein hydrolysate from soybean protein concentrate was produced using papain. The peptides were separated by ultrafiltration (< and > 3 kDa, LMMH (low molecular mass) and HMMH (high molecular mass), respectively) and sequenced through LC-MS/MS. To obtain a thorough identification of the peptides in the hydrolysate, different analysis methods and bioinformatics techniques were applied, covering a molecular mass range from more than 480 Da up to small dipeptides. The antioxidant and the inhibitory α -glucosidase and lipase potentials were evaluated by different in vitro tests. Sixty-nine peptides were identified in the HMMH fraction and 32 in LMMH, but only 16 matched the 118 sequences obtained by in silico simulated hydrolysis. Unlike previous reports, the HMMH fraction showed higher antioxidant activity, by all 5 in vitro methods applied, which was not accompanied by the in silico evaluation. Both high and low molecular mass fractions showed similar inhibitory activities against α -glucosidase and pancreatic lipase. LMMH, however, showed better results for α -glucosidase inhibition (IC50 = 0,94), in agreement with the in silico evaluation. This combination of bioactivities makes the fractions of this hydrolysate potential food ingredients with the possible ability to delay the lipid peroxidation of meat products, limiting the digestion of lipids in the product and also with the potential to delay the digestion of carbohydrates ingested in the same meal.

Investigating Cold Dust Properties of 12 Nearby Dwarf Irregular Galaxies by Hierarchical Bayesian Spectral Energy Distribution Fitting

Abstract Combining infrared and submillimeter observations and applying a two-temperature modified blackbody (TMBB) model with a hierarchical Bayesian technique, we model the spectral energy distribution of 12 nearby dwarf irregular (dIrr) galaxies. We aim to probe potential submillimeter excess emission at 350, 500, and 850 μm and investigate the properties of cold dust parameters. Based on the TMBB model with cold dust emissivity index (β c) fixed to 2, one galaxy shows 500 μm excess emission and nine galaxies show excess at 850 μm (five of them still show 850 μm excess in the case of free β c). We find that the 850 μm excess emission is easily detected in the dIrr galaxies with low star formation activity. The 850 μm excess is more frequent and more prominent in dIrr galaxies with low molecular hydrogen gas mass fraction or low ratios between cold dust mass and gas mass. As galaxies evolve, the ratios between atomic hydrogen gas mass and stellar mass decrease and the 850 μm excess emission tends to decrease or even disappear. Our results suggest that the cold dust temperature may increase, as the dIrr galaxies have more intense star formation or richer metallicity. There is a weak anticorrelation between the cold dust-to-stellar mass ratio and the specific star formation rate for our galaxies.

Bothrops moojeni Venom and Its Components Strongly Affect Osteoclasts' Maturation and Protein Patterns.

Osteoclasts (OCs) are important for bone maintenance, calcium balance, and tissue regeneration regulation and are involved in different inflammatory diseases. Our study aimed to evaluate the effect of Bothrops moojeni’s venom and its low and high molecular mass (HMM and LMM) fractions on human peripheral blood mononuclear cell (PBMC)-derived OCs’ in vitro differentiation. Bothrops moojeni, a Brazilian lanced-head viper, presents a rich but not well-explored, venom composition. This venom is a potent inducer of inflammation, which can be used as a tool to investigate the inflammatory process. Human PBMCs were isolated and induced to OC differentiation following routine protocol. On the fourth day of differentiation, the venom was added at different concentrations (5, 0.5, and 0.05 µg/mL). We observed a significant reduction of TRAP+ (tartrate-resistant acid phosphatase) OCs at the concentration of 5 µg/mL. We evaluated the F-actin-rich OCs structure’s integrity; disruption of its integrity reflects bone adsorption capacity. F-actin rings phalloidin staining demonstrated that venom provoked their disruption in treated OCs. HMM, fraction reduces TRAP+ OCs at a concentration of 5 µg/mL and LMM fraction at 1 µg/mL, respectively. Our results indicate morphological changes that the venom induced cause in OCs. We analyzed the pattern of soluble proteins found in the conditioned cell culture medium OCs treated with venom and its fractions using mass spectrometry (LC-MS/IT-Tof). The proteomic analyses indicate the possible pathways and molecular mechanisms involved in OC reduction after the treatment.

Protective effects of distinct proline-rich oligopeptides from B. jararaca snake venom against oxidative stress-induced neurotoxicity

The low molecular mass fraction from Bothrops jararaca snake venom contains proline-rich peptides (Bj-PROs), also known as bradykinin-potentiating peptides (BPPs), which were described as neuroprotective against H2O2-induced oxidative stress. Recently, we reported that the neuroprotective action of Bj-PRO-10c (<ENWPHPQIPP) is a result of an increase in the expression and activity of argininosuccinate synthase (AsS), thereby improving increase L-arginine synthesis. It is proposed that formation agmatine and polyamines from L-arginine metabolism are neuroprotective, reducing lipid peroxidation, oxidative stress, and maintenance of the mitochondrial membrane. In the present study, Bj-PRO-5a (<EKWAP), Bj-PRO-7a (<EDGPIPP), Bj-PRO-11e (<EARPPHPPIPP), and Bj-PRO-AP (<EARPPHPPIPPAP) – with different structure-activities, in particular on AsS expression and activity – were selected to study their protective properties on H2O2-induced oxidative stress in SH-SY5Y cells. Bj-PROs tested were neuroprotective, but Bj-PRO-5a and Bj-PRO-7a increased cell viability by more than 85% in the presence of H2O2 (450 μM) and reduced the oxidative stress markers. AsS, iNOS, and NF-ĸB expressions were not involved in the neuroprotective mechanism for both peptides, in contrast to Bj-PRO-10c, as reported in the literature. Bj-PRO-5a is a neuroprotector peptide that decreases ROS production, NO levels lipid peroxidation, and changes in mitochondrial membrane permeability caused by H2O2 exposition. The neuroprotective property of Bj-PRO-7a against H2O2 is also related to decreased ROS production and lipid peroxidation but without altering NO levels. These results show that the protective effects of different Bj-PROs against oxidative stress can be explained by distinct mechanisms independent of an increase in L-arginine bioavailability arising from AsS activity. Further studies are now needed to reveal the details of the neuroprotective mechanisms exerted by Bj-PROs.

Diels–Alder Hyperbranched Pyridylphenylene Polymer Fractions as Alternatives to Dendrimers

The results of the hydrodynamic study of hyperbranched pyridylphenylene polymers synthesized via Diels–Alder cycloaddition reaction of multifunctional monomers are reported. The synthesized polymers were fractionated into a much narrowly dispersed fractions. The in-depth analysis of molecular characteristics and conformation of the initial polymers and corresponding fractions was performed using the unique combination of hydrodynamic approaches. The intercorrelation and self-consistency of obtained data were ensured using the hydrodynamic invariant concept and classical Kuhn–Mark–Houwink–Sakurada scaling relations. The evaluated data suggest that hyperbranched pyridylphenylene demonstrates the hydrodynamic behavior typical for asymmetrical compact macromolecular species. Furthermore, hydrodynamic characteristics of herein studied hyperbranched pyridylphenylene polymer fractions were compared with known hydrodynamic data for pyridylphenylene dendrimers. Nearly identical hydrodynamic behavior was found for the compared macromolecules, especially for low molecular mass fractions, which may suggest that the fractionation of hyperbranched polymers results in dendrimer-like structures. The oblate ellipsoid model provides reasonable correlation between hydrodynamic properties of hyperbranched pyridylphenylene polymer fractions and pyridylphenylene dendrimers.

Effect of metal ions on levan synthesis efficiency and its parameters by levansucrase from Bacillus subtilis.

Levan is a fructan whose backbone is composed of β-(2-6) linkages. It is synthetized by the enzyme levansucrase (EC 2.4.1.10). The effect of Fe3+, K+, Mg2+, Mn2+, and Zn2+ in the range of 0-1 mM on parameters of levan was tested using design of response surface experiment. The bimodal distribution of levan was observed, however, the concentration of high molecular mass fraction (weight average molar mass, Mw = 1.9 · 107 ± 3.4 · 104 g/mol and intrinsic viscosity, [η] = 0.206 ± 0.016 dL/g,) was not >4% of the total yield of levan. The metal ions in the reaction medium had an effect on parameters of low molecular mass levan and the efficiency of synthesis. Molar mass distribution of abundant, low molecular mass fraction was in the range of 4.33 · 104 g/mol to 9.77 · 104 g/mol; [η] was 0.040-0.075 dL/g while the efficiency of transfructosylation was within the range of 61.4to 69.1%. It was observed that the molar mass of levan depends on Fe3+ concentration while intrinsic viscosity is affected by the concentration of Mn2+ in the reaction medium. The GPC (with triple detection) data was analyzed using response surface methodology (RSM), k-means and principal component analysis (PCA).

Bradykinin-potentiating PEPTIDE-10C, an argininosuccinate synthetase activator, protects against H2O2-induced oxidative stress in SH-SY5Y neuroblastoma cells

Bradykinin-potentiating peptides (BPPs – 5a, 7a, 9a, 10c, 11e, and 12b) of Bothrops jararaca (Bj) were described as argininosuccinate synthase (AsS) activators, improving l-arginine availability. Agmatine and polyamines, which are l-arginine metabolism products, have neuroprotective properties. Here, we investigated the neuroprotective effects of low molecular mass fraction from Bj venom (LMMF) and two synthetic BPPs (BPP-10c, <ENWPHPQIPP; BPP-12b, <EWGRPPGPPIPP) in the SH-SY5Y cell line against H2O2-induced oxidative stress. The neuroprotective effects against H2O2-induced were analyzed by reactive oxygen species (ROS – DCFH) production; lipid peroxidation (TBARS); intracellular GSH; AsS, iNOS, and NF-kB expressions; nitrite levels (Griess); mitochondrial membrane potential (TMRM); and antioxidant activity (DPPH). Analysis of variance followed by Tukey’s post hoc test were calculated for statistical comparisons. Pre-treatment with both BPPs significantly reduced cell death induced by H2O2, but BPP-10c showed higher protective capacity than BPP-12b. LMMF pretreatment was unable to prevent the reduction of cell viability caused by H2O2. The neuroprotective mechanism of BPP-10c against oxidative stress was investigated. BPP-10c reduced ROS generation and lipid peroxidation in relation to cells treated only with H2O2. BBP-10c increased AsS expression and was not neuroprotective in the presence of MDLA, a specific inhibitor of AsS. BPP-10c reduced iNOS expression and nitrate levels but decreased NF-kB expression. Furthermore, BPP-10c protected the mitochondrial membrane against oxidation. Overall, we demonstrated for the first time neuroprotective mechanisms of BPPs against oxidative stress, opening new perspectives to the study and application of these peptides for the treatment of neurodegenerative diseases.

Components in Lentinus edodes mushroom with anti-biofilm activity directed against bacteria involved in caries and gingivitis.

The present study investigated the compounds present in the low molecular mass fraction of Lentinus edodes mushroom (shiitake) extract and their anti-virulence activity against oral pathogens (reference and clinical Streptococcus mutans, Actinomyces naeslundii, and Prevotella intermedia strains). Oxalic, succinic, and quinic acids, and adenine, inosine, and uridine were identified by HPLC-DAD-ESI-MS/MS. Their anti-biofilm production and preformed biofilm disaggregation activities were studied using commercial standard compounds at different concentrations. As regards S. mutans, the highest activity was shown by adenine at 5 mg mL-1 both in the biofilm inhibition (BI 50%) and biofilm disaggregation tests (BD 20%). Considering A. naeslundii, BI values close to 80% were registered for oxalic acid at 1 mg mL-1 and 2 mg mL-1 and BD 50% for quinic acid at 3 mg mL-1. A weaker activity was found against P. intermedia. Furthermore, different mixtures of the commercial standards were tested showing that the activity of a compound can be strongly and sometimes negatively affected by the presence of the other compounds.

SÍGAME Simulations of the , , and Line Emission from Star-forming Galaxies at

Abstract Of the almost 40 star-forming galaxies at (not counting quasi-stellar objects) observed in to date, nearly half are either very faint in or not detected at all, and fall well below expectations based on locally derived relations between star formation rate and luminosity. This has raised questions as to how reliable is as a tracer of star formation activity at these epochs and how factors such as metallicity might affect the emission. Combining cosmological zoom simulations of galaxies with SÍGAME (SImulator of GAlaxy Millimeter/submillimeter Emission), we modeled the multiphased interstellar medium (ISM) and its emission in , as well as in [O i] and [O iii], from 30 main-sequence galaxies at with star formation rates ∼3–23 , stellar masses , and metallicities . The simulations are able to reproduce the aforementioned faintness of some normal star-forming galaxy sources at . In terms of [O i] and [O iii], very few observations are available at , but our simulations match two of the three existing detections of [O iii] and are furthermore roughly consistent with the [O i] and [O iii] luminosity relations with star formation rate observed for local starburst galaxies. We find that the emission is dominated by the diffuse ionized gas phase and molecular clouds, which on average contribute ∼66% and ∼27%, respectively. The molecular gas, which constitutes only of the total gas mass, is thus a more efficient emitter of than the ionized gas, which makes up ∼85% of the total gas mass. A principal component analysis shows that the luminosity correlates with the star formation activity of a galaxy as well as its average metallicity. The low metallicities of our simulations together with their low molecular gas mass fractions can account for their faintness, and we suggest that these factors may also be responsible for the -faint normal galaxies observed at these early epochs.

Venomics analyses of the skin secretion of Dermatonotus muelleri: Preliminary proteomic and metabolomic profiling

Dermatonotus muelleri is the sole species of the Dermatonotus genus and inhabits Argentina, Bolivia, Brazil and Paraguay. This animal exhibits an explosive reproductive behavior during the Southern spring months, which lasts only for five days. Moreover, this animal displays specific adaptations to the habitat resulting in the energy conservation needed during either the intense reproduction period or times of estivation. During dry seasons and/or food shortages D. muelleri can survive because its food specialization and ability to dig an underground chamber for protection. Few literature is available on this amphibian and no biochemical characterization has ever been performed on the animal's skin secretion. This work, on the other hand, presents for the first time a venomic analysis of the major components present in the skin secretion of this microhylid. The crude skin secretion was obtained my mechanical stimulation and was analyzed according to one major criterion: >10 kDa or <10 kDa. The high molecular mass fraction was subjected to typical gel-based proteomic processing whereas the low molecular mass fraction was analyzed by liquid chromatography, mass spectrometry and nuclear magnetic resonance (NMR), yielding an overall ‘venomics’ approach. No classical/evident toxin was detected, but peptidases (metallo and serino) and structural proteins could be identified. In the low molecular mass fraction no peptides were detected, as well as no typical alkaloid or steroid. On the other hand, the amino acid tryptophan could be identified and a typical sugar spectrum was obtained in the NMR analyses. Altogether these findings point out to the fact that D. muelleri skin secretion is unique and the molecular arsenal present herein is yet to be explored; therefore, this venomics study is only the beginning.

Extracellular presence/release of galectins from HTR-8/SVneo extravillous trophoblast cells*

Galectins (gals) are s-galactoside binding lectins, involved in many processes at the fetomaternal interface where they can exert their roles both in and out of cells. The aim of this work was to explore the extracellular presence/release of HTR-8/SVneo extravillous trophoblast cell line galectins. To that end, conditioned medium (CM) from HTR-8/SVneo cell culture was fractionated into a high molecular mass fraction (HMF) and low molecular mass fraction (LMF) using 100 kDa cut-off concentrators. In addition, extracellular vesicles (EVs) were isolated from CM by ultracentrifugation. Size and shape of the EVs were analyzed by transmission electron microscopy and their galectin mRNA content was determined by real-time PCR. The presence of galectins in fractions of HTR-8/SVneo CM and EVs was detected by western blot. All three galectins expressed by HTR-8/SVneo cells (gal-1, gal-3, and gal-8) were detected in the CM, HMF, and EVs, while only gal-1 was found in the LMF. In addition, EVs contained all three galectin mRNAs. These results reveal that free, complexed, and EV-associated forms of galectins were released from extravillous trophoblast cells, suggesting their potential to exert extracellular functions both in their immediate vicinity at the fetomaternal interface and distant locations.

Scientific opinion on the evaluation of substances as acceptable previous cargoes for edible fats and oils.

Shipping of edible fats and oils into Europe is permitted in bulk tanks, provided that the previous cargo is included in a positive list. The European Commission requested EFSA to evaluate the acceptability as previous cargoes for fats and oils the substances calcium lignosulphonate, methyl acetate, ethyl tert‐butyl ether (ETBE) and ammonium sulphate. The evaluation was based on the same criteria as those used for the evaluation of the substances currently on the list in the Annex to Commission Directive 96/3/EC as acceptable previous cargoes for edible fats and oils. Methyl acetate and ETBE meet the criteria for acceptability as previous cargoes. Due to uncertainties, mainly with regard to the composition and toxicity of the low molecular mass fraction, and the fact that the toxicological database is limited to the 40–65 grade and does not cover all grades of calcium lignosulphonate shipped as previous cargoes, the EFSA Panel on Contaminants in the Food Chain (CONTAM Panel) concluded that calcium lignosulphonate does not meet the criteria for acceptability as a previous cargo. Only food‐grade ammonium sulphate meets the criteria for acceptability as a previous cargo due to uncertainties about impurities in other (non‐food) grades.

An unexpected cell-penetrating peptide from Bothrops jararaca venom identified through a novel size exclusion chromatography screening.

Efficient drug delivery systems are currently one of the greatest challenges in pharmacokinetics, and the transposition of the gap between in vitro candidate molecule and in vivo test drug is, sometimes, poles apart. In this sense, the cell-penetrating peptides (CPP) may be the bridge uniting these worlds. Here, we describe a technique to rapidly identify unlabeled CPPs after incubation with liposomes, based on commercial desalting (size exclusion) columns and liquid chromatography-MS/MS, for peptide de novo sequencing. Using this approach, we found it possible to identify one new CPP - interestingly, a classical bradykinin-potentiating peptide - in the peptide-rich low molecular mass fraction of the Bothrops jararaca venom, which was also able to penetrate live cell membranes, as confirmed by classical approaches employing fluorescence-labeled analogues of this CPP. Moreover, both the labeled and unlabeled CPPs caused no metabolic, cell-cycle or morphologic alterations, proving to be unmistakably cargo deliverers and not drugs themselves. In sum, we have developed and validated a method for screening label-free peptides for CPP activity, regardless of their biological origin, which could lead to the identification of new and more efficient drug delivery systems. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd.

Aquatic macrophytes in Ethiopian Rift Valley lakes; Their trace elements concentration and use as pollution indicators

Trace elements (TEs) uptake from water and sediments to 10 aquatic macrophytes in the Ethiopia Rift Valley lakes Koka, Ziway and Awassa was investigated to evaluate pollution of these lakes. Concentrations of Cr, Co, Ni, Cu, Zn, As, Se, Cd, Pb and Mn have been determined in leaves of macrophytes, water and sediment, using ICP-MS (Inductively Coupled Plasma–Mass Spectrometry). Principal component analysis showed an existing variation in TEs concentration in leaves of aquatic macrophytes. High concentration of Mn (1.6×103 and 1.2×103mgkg−1 dw) was found in Aeschynomene elaphroxylon of Lake Ziway and Eichhornia crassipes of Lake Koka, respectively. Cr concentration in low molecular mass (LMM) fraction of water and total sediment (4.9μgL−1 and 95±4mgkg−1 dw, respectively) was higher in Lake Koka compared to lakes Ziway and Awassa. Some of the studied macrophytes can accumulate high level of trace elements concentration compared to the surrounding, showing their potential to be utilized as pollution indicators. Most TEs in macrophytes used as animal feed, such as Echinochloa stagnina (Retz.) P. Beauv, were sufficiently low.

Effect of Composting on the Behavior of Polyolefin Films - A True-to-Life Experiment

Commercial polypropylene (PP), high-, medium- and low density polyethylene (HDPE, MDPE, LDPE) films, as well as MDPE films containing pro-oxidative additives and thermoplastic starch (TPS) were composted for six weeks together with biologically degradable films, such as poly (lactic acid) (PLA), Ecovio (BASF), Mater Bi(Novamont) and cellophane. Visual appearance of the polyolefin-based films did not change significantly, while the biologically degradable films fell apart. Thickness and mechanical properties of the polyolefin-based films also did not vary significantly after composting. The thickness of the degradable films however increased due to biofilm formation and finally decreased due to biodegradation, and their mechanical properties drastically dropped. FTIR proved the formation of carbonyl absorption of commercial and of the additive-containing films respectively) after composting due to oxidation. The FTIR-spectrum of the biodegradable films showed drastic change after composting. Formation of free radicals was detectable by ESR-spectroscopy, if pro-oxidative additive containing MDPE film was exposed for one week to sunlight, and the intensity of free radical formation increased after composting. The number-average molecular mass of MDPE films containing pro-oxidative additives decreased, low molecular mass fractions appeared and polydispersity increased after composting. Commercial polyolefin films were covered by microorganisms much more densly than films containing pro-oxidative additives detected by SEM. Even TPS did not increase the quantity of microorganisms. Biodegradable films were densly covered by microorganisms of different types and they became porous and holes were observable on their surface. It can be concluded that composting had no significant effect on the behaviour of the commercial PP and PE films. Signs of initial degradation were observable on MDPE films with pro-oxidative additives and TPS after 6 weeks composting, although it cannot be considered as biological degradation. Non of the tested polyolefin films suffered such degree of degradation in compost, as the biologically degradable films. It may be concluded that polyolefin films neither degrade in compost nor they undergo biodegradation.

Proteomic analysis of the rare Uracoan rattlesnake Crotalus vegrandis venom: Evidence of a broad arsenal of toxins

The investigation of venoms has many clinical, pharmacological, ecological and evolutionary outcomes. The Crotalus spp. venom can cause hemorrhage, neurotoxicity, myotoxicity, coagulopathy and hypotension. Although neurotoxicity and hemorrhage usually does not occur for the same species, the rare Venezuelan species Crotalus vegrandis presents both characteristic. Different from the other species it has a restricted ecological niche and geographical distribution. Nevertheless, it has a raising medical importance as this rattlesnake population is increasing. Few works describe its neurotoxic and hemorrhagic features, but other toxins might play an important role in envenomation. We combined proteomic methods to identify for the first time the main components of it venom: 2D SDS-PAGE and gel-filtration chromatography for protein mixture decomplexation; LC-MS2 of low molecular mass fractions and tryptic peptides; bioinformatic identification of toxin families and specific protein species based on unique peptide analysis and sequence database enriched with species-specific venom gland transcripts; and finally polyclonal anti-crotamine Western-blotting. Our results point to a broad arsenal of toxins in C. vegrandis venom: PIII and PII metalloproteases, crotoxin subunits, other phospholipases, isoforms of serine proteases and lectins, l-amino-acid oxidase, nerve growth factor, as well as other less abundant toxins.

Tumor-derived α-fetoprotein impairs the differentiation and T cell stimulatory activity of human dendritic cells.

Several tumor-derived factors have been implicated in dendritic cell (DC) dysfunction in cancer patients. α-fetoprotein (AFP) is an oncofetal Ag that is highly expressed in abnormalities of prenatal development and several epithelial cancers, including hepatocellular carcinoma (HCC). In HCC patients exhibiting high levels of serum AFP, we observed a lower ratio of myeloid/plasmacytoid circulating DCs compared with patients with low serum AFP levels and healthy donors. To test the effect of AFP on DC differentiation in vitro, peripheral blood monocytes from healthy donors were cultured in the presence of cord blood-derived normal AFP (nAFP) or HCC tumor-derived AFP (tAFP), and DC phenotype and function were assessed. Although the nAFP and tAFP isoforms only differ at one carbohydrate group, low (physiological) levels of tAFP, but not nAFP, significantly inhibited DC differentiation. tAFP-conditioned DCs expressed diminished levels of DC maturation markers, retained a monocyte-like morphology, exhibited limited production of inflammatory mediators, and failed to induce robust T cell proliferative responses. Mechanistic studies revealed that the suppressive activity of tAFP is dependent on the presence of low molecular mass (LMM) species that copurify with tAFP and function equivalently to the LMM fractions of both tumor and nontumor cell lysates. These data reveal the unique ability of tAFP to serve as a chaperone protein for LMM molecules, both endogenous and ubiquitous in nature, which function cooperatively to impair DC differentiation and function. Therefore, novel therapeutic approaches that antagonize the regulatory properties of tAFP will be critical to enhance immunity and improve clinical outcomes.

Involvement of ligninolytic enzymes in degradation of wheat straw by Trametes trogii.

Wheat straw is generated in billions of tons around the world every year and has not been fully used. This study sought to evaluate the delignification capacity and enzyme production of Trametes trogii MT strain and to clarify the changes of structure and chemical composition of wheat straw during the decay process. The results obtained revealed that the T.trogii MT strain has the ability to degrade lignin, cellulose as well as hemicellulose of wheat straw simultaneously. The strain can produce high activities of laccase, manganese peroxidase, xylanase, carboxymethylcellulase and feruloyl esterase but no lignin peroxidases during the decay process of a 60-day incubation period on wheat straw. Scanning electron microscopy observation and infrared spectroscopy analysis showed the lignin and carbohydrate of wheat straw were degraded with no obvious different levels. The low molecular mass fractions collected from the culture of the MT strains grown in wheat straw powder liquid medium showed high Fe(3+) chelating, reducing capacity and hydroxyl radical and hydrogen peroxide generation. Trametes trogii MT has a complex mechanism to degrade lignocellulose, in addition to the extracellular enzymatic systems, and has great potential as an attractive micro-organism used for the biological degradation of waste straws. This study revealed the dynamic changes of the ligninolytic enzymes of T.trogii MT during the degradation of wheat straw, and suggested that the decay patterns of wheat straw by T.trogii MT had some simultaneous type characteristics.