Binding of madindoline A to the extracellular domain of gp130

Elevated levels of IL-6 and IL-11 are associated with multiple myeloma, rheumatoid arthritis, hypercalcemia, cancer cachexia, and Castleman's disease. Madindoline A (MadA), isolated from Streptomyces nitrosporeus K93-0711, specifically inhibits the growth of IL-6- and IL-11-dependent cell lines, most likely by interfering with the homodimerization of gp130. This raises the possibility that MadA can be used as a model compound for the development of novel chemotherapeutic agents. In this report, we demonstrate that the binding of MadA to gp130 is specific and noncovalent, and displays a relatively low affinity. Furthermore, we show that the tricyclic 3a-hydroxytetrahydrofuro[2,3-b]indole (HFI) moiety of MadA alone is not sufficient for binding. Matrix-bound MadA precipitates a protein composed of the extracellular domain of gp130 fused to the Fc region of the immunoglobulin heavy chain. Binding is inhibited in a dose-dependent manner by preincubation with free MadA. The K(D) for binding of MadA to gp130 is 288 microM, as determined by surface plasmon resonance (SPR)-based biosensor analysis. The HFI portion of MadA does not bind to gp130 in either affinity precipitation or SPR analyses. Finally, MadA, but not the HFI portion, inhibits IL-6-dependent Stat3 tyrosine phosphorylation in HepG2 cells.     

Expression and secretion of human apolipoprotein A-I in the heart

Nuclear envelope-peripheral heterochromatin fractions contain multiple histone kinase activities. In vitro assays and amino-terminal sequencing show that one of these activities co-isolates with heterochromatin protein 1 (HP1) and phosphorylates histone H3 at threonine 3. Antibodies recognizing this post-translational modification reveal that in vivo phosphorylation at threonine 3 commences at early prophase in the vicinity of the nuclear envelope, spreads to pericentromeric chromatin during prometaphase and is fully reversed by late anaphase. This spatio-temporal pattern is distinct from H3 phosphorylation at serine 10, which also occurs during cell division, suggesting segregation of differentially phosphorylated chromatin to different regions of mitotic chromosomes.     

Mediation by indole analogues of electron transfer during oxygen activation in variants of Escherichia coli ribonucleotide reductase R2 lacking the electron-shuttling tryptophan 48

Activation of dioxygen by the carboxylate-bridged diiron(II) cluster in the R2 subunit of class I ribonucleotide reductase from Escherichia coli results in the one-electron oxidation of tyrosine 122 (Y122) to a stable radical (Y122*). A key step in this reaction is the rapid transfer of a single electron from a near-surface residue, tryptophan 48 (W48), to an adduct between O(2) and diiron(II) cluster to generate a readily reducible cation radical (W48(+)(*)) and the formally Fe(IV)Fe(III) intermediate known as cluster X. Previous work showed that this electron injection step is blocked in the R2 variant with W48 replaced by phenylalanine [Krebs, C., Chen, S., Baldwin, J., Ley, B. A., Patel, U., Edmondson, D. E., Huynh, B. H., and Bollinger, J. M., Jr. (2000) J. Am. Chem. Soc. 122, 12207-12219]. In this study, we show that substitution of W48 with alanine similarly disables the electron transfer (ET) but also permits its chemical mediation by indole compounds. In the presence of an indole mediator, O(2) activation in the R2-W48A variant produces approximately 1 equiv of stable Y122* and more than 1 equiv of the normal (micro-oxo)diiron(III) product. In the absence of a mediator, the variant protein generates primarily altered Fe(III) products and only one-fourth as much stable Y122* because, as previously reported for R2-W48F, most of the Y122* that is produced decays as a consequence of the inability of the protein to mediate reductive quenching of one of the two oxidizing equivalents of the initial diiron(II)-O(2) complex. Mediation of ET is effective in W48A variants containing additional substitutions that also impact the reaction mechanism or outcome. In the reaction of R2-W48A/F208Y, the presence of mediator suppresses formation of the Y208-derived diiron(III)-catecholate product (which is predominant in R2-F208Y in the absence of reductants) in favor of Y122*. In the reaction of R2-W48A/D84E, the presence of mediator affects the outcome of decay of the peroxodiiron(III) intermediate known to accumulate in D84E variants, increasing the yield of Y122* by as much as 2.2-fold to a final value of 0.75 equiv and suppressing formation of a 490 nm absorbing product that results from decay of the two-electron oxidized intermediate in the absence of a functional ET apparatus.     

Cephalosporium maydis is a distinct species in the Gaeumannomyces-Harpophora species complex

Cephalosporium maydis is an important plant pathogen whose phylogenetic position relative to other fungi has not been established clearly. We compared strains of C. maydis, strains from several other plant-pathogenic Cephalosporium spp. and several possible relatives within the Gaeumannomyces-Harpophora species complex, to which C. maydis has been suggested to belong based on previous preliminary DNA sequence analyses. DNA sequences of the nuclear genes encoding the rDNA ITS region, β-tubulin, histone H3, and MAT-2 support the hypothesis that C. maydis is a distinct taxon within the Gaeumannomyces-Harpophora species complex. Based on amplified fragment length polymorphism (AFLP) profiles, C. maydis also is distinct from the other tested species of Cephalosporium, Phialophora sensu lato and members of Gaeumannomyces-Harpophora species complex, which supports its classification as Harpophora maydis. Oligonucleotide primers for H. maydis were developed that can be used in a PCR diagnostic protocol to rapidly and reliably detect and identify this pathogen. These diagnostic PCR primers will aid the detection of H. maydis in diseased maize because this fungus can be difficult to detect and isolate, and the movement of authentic cultures may be limited by quarantine restrictions.     

Effects of high-relief structures on cold temperate fish assemblages: A field experiment

High-relief structures may influence the abundance and diversity of reef-associated fish. We conducted a field experiment to investigate whether the presence of vertical structures (PVC pipes) affects fish communities on artificial reefs. The effect of the height of the structures (1 and 3 m) was also tested. Furthermore, the effects on fish of placing artificial reefs on otherwise featureless bottoms were quantified. Algal and macro-invertebrate colonization of the reefs was also recorded. The experiment was carried out on the west coast of Sweden over a period of 1 year. The vertical structures had a positive effect on fish abundance but not on diversity. The height of the structures did not, however, influence the fish communities. Natural as well as urban vertical structures on the seafloor could have a positive effect on local fish abundance. The positive effects of artificial reefs on total fish abundance and diversity were immediate. Of the 10 species recorded, two, the black goby Gobius niger and the goldsinny wrasse Ctenolabrus rupestris, dominated over the whole survey period. There were significant temporal differences in fish abundance, and diversity increased with time.     

High incidence of deafness from three frequent connexin 26 mutations in an isolated community

In a small village founded by few ancestors, three mutations in GJB2, the gene for connexin 26, are responsible for the high prevalence of deafness. A total of 15% of healthy individuals from a random sample were carriers of either 35Gdel (7.8%), W77R (2.4%), or V37I (4.8%). The three mutations appeared in the village approximately 100-150 years ago. The question of why three distinct mutations of similar age are observed at high frequency within a genetic isolate is discussed.     

Anti-biofilm activity of Salvadora persica on cariogenic isolates of Streptococcus mutans: in vitro and molecular docking studies

Salvadora persica sticks are used for chewing and oral-hygiene measures worldwide. The growth inhibition and anti-biofilm effects of various extracts on cariogenic Streptococcus mutans isolates were evaluated. Biofilm inhibition, gas chromatography-mass spectrometry (GC-MS) analyses for phytochemicals and their possible mode of interaction with biofilm response regulators were revealed using LigandFit docking protocols. All S. persica extracts showed considerable inhibitory activity and the cariogenic S. mutans showed varied susceptibility when compared with controls. The percentage reduction in biofilm inhibition obtained for methanol, ethanol, chloroform, acetone, and aqueous extracts were 87.92%, 85.75%, 72.44%, 61.66% and 58.68%, respectively. GC-MS analyses revealed?>28 compounds, of which benzyl (6Z,9Z,12Z)-6,9,12-octadecatrienoate, 3-benzyloxy-1-nitro-butan-2-ol and 1,3-cyclohexane dicarbohydrazide interacted efficiently with the bacterial communication quorum-sensing (QS) regulators Streptococcus OmpP and Staphylococcus Lux proteins. The bioactive, dual-function, anti-biofilm agents in S. persica not only inhibit growth, but also control the colonization and accumulation of caries-causing S. mutans.     

Chemical alterations taken place during deep-fat frying based on certain reaction products: A review

Deep-fat frying at 180°C or above is one of the most common food processing methods used for preparing of human kind foods worldwide. However, a serial of complex reactions such as oxidation, hydrolysis, isomerization, and polymerization take place during the deep-fat frying course and influence quality attributes of the final product such as flavor, texture, shelf life and nutrient composition. The influence of these reactions results from a number of their products including volatile compounds, hydrolysis products, oxidized triacylglycerol monomers, cyclic compounds, trans configuration compounds, polymers, sterol derivatives, nitrogen- and sulphur-containing heterocyclic compounds, acrylamide, etc. which are present in both frying oil and the fried food. In addition, these reactions are interacted and influenced by various impact factors such as frying oil type, frying conditions (time, temperature, fryer, etc.) and fried material type. Based on the published literatures, three main organic chemical reaction mechanisms namely hemolytic, heterolytic and concerted reaction were identified and supposed to elucidate the complex chemical alterations during deep-fat frying. However, well understanding the mechanisms of these reactions and their products under different conditions helps to control the deep-fat frying processing; therefore, producing healthy fried foods. By means of comprehensively consulting the papers which previously studied on the chemical changes occurred during deep-fat frying process, the major reaction products and corresponding chemical alterations were reviewed in this work.