Polyethylene glycol promotes autoxidation of cytochrome c

Cytochrome c (Cyt c) was rapidly oxidized by molecular oxygen in the presence, but not absence of PEG. The redox potential of heme c was determined by the potentiometric titration to be +236?±?3?mV in the absence of PEG, which was negatively shifted to +200?±?4?mV in the presence of PEG. The underlying the rapid oxidation was explored by examining the structural changes in Cyt c in the presence of PEG using UV–visible absorption, circular dichroism, resonance Raman, and fluorescence spectroscopies. These spectroscopic analyses suggested that heme oxidation was induced by a modest tertiary structural change accompanied by a slight shift in the heme position (<1.0?Å) rather than by partial denaturation, as is observed in the presence of cardiolipin. The near-infrared spectra showed that PEG induced dehydration from Cyt c, which triggered heme displacement. The primary dehydration site was estimated to be around surface-exposed hydrophobic residues near the heme center: Ile81 and Val83. These findings and our previous studies, which showed that hydrated water molecules around Ile81 and Val83 are expelled when Cyt c forms a complex with CcO, proposed that dehydration of these residues is functionally significant to electron transfer from Cyt c to CcO.     

Distribution of hydraulic resistance in seedlings,sprouts and an adult tree ofPasania edulis Makino

Hydraulic resistance is an important factor in predicting water status. Hydraulic resistance of petiols, stems and branches, and roots was measured inPasania edulis Makino in order to compare the distribution of resistance between current seedlings, current stump sprouts and a 16 year old adult tree. Total resistance showed only minor variations despite large variations in plant size. This result is thought to be consistent with allometry between leaf mass and supportive organ mass, and with changes in permeability of conductive organs. Root resistance was low in sprouts and the adult tree due to their mature root systems. Current seedlings with undeveloped root systems had high root resistance. The proportion of petiol resistance in total resistance was high compared to the proportion of their conductive distance, and was thought to be a limiting factor of tree water status. The petiol resistance of the adult tree leaves was higher than for seedling and sprout leaves. From a comparison with the leaf water relation characteristics, the petiol resistance was thought to be provided as low values for intolerant leaves against water stress in order to compensate water inflow, and high values for tolerant leaves to regulate water inflow.     

Fermented milk, Kefram-Kefir enhances glucose uptake into insulin-responsive muscle cells

Diminution of insulin-responses in the target organ is the primary cause of non-insulin dependent diabetes mellitus (NIDDM).It is thought to be correlated to the excessive production of reactive oxygen species (ROS). In this article, we attempted to evaluate whether fermented milk, Kefram-Kefir known as an antioxidant, reduces the cellular ROS levels and can stimulate the glucose uptake in L6 skeletal muscle cells. Water-soluble or chloroform/methanol-extracted fractions from Kefram-Kefir were examined to evaluate the glucose uptake ability of L6 myotubes.As a result, the water-soluble fraction augmented the uptake of glucose in L6 myotubes both in the presence and absence of insulin stimulation. Estimation of intracellular ROS level revealed that the water-soluble fraction of Kefram-Kefir reduced the intracellular ROS level on both the undifferentiated and differentiated L6 cells. Especially, glucose uptake was augmented up to six times with the addition of water-soluble fraction in the insulin-stimulated L6 myotubes. Glucose transport determination revealed that the active agent in Kefram-Kefir was resistant to autoclave and stable in pH range from 4 to 10, and the small molecule below the molecular weight of 1000. Furthermore, this augmentation was inhibited in the presence of phosphatidylinositol 3-kinase (PI 3-kinase) inhibitor wortmannin. Considering together with the reports that PI 3-kinase is locatedin the insulin signaling pathway and the participation in the translocation of glucose transporter 4 to the cell membrane, it is suggested that the water-soluble fraction of Kefram-Kefir activates PI 3-kinase or other upstream molecules in the insulin signaling pathway, which resulted in the augmentation of glucose uptake and its specific inhibition by wortmannin. This revised version was published online in August 2006 with corrections to the Cover Date.     

Physics underlying the formation of protocells

The emergence of the first cellular organization on the primitive earth could be associated with pronounced heterotrophic activity embodied in heat engines actualized in local material aggregates. Heterotrophic activity intrinsically rests upon the capacity of local detection upholding the conservation of energy on the global scale.     

Clonal propagation of Cephaelis ipecacuanha

Shoot cultures of Cephaelis ipecacuanha A. Richard were established by using shoot tips as initial explants. Multiple shoots were obtained from node segments upon culture on B5 medium supplemented with NAA-BA (0.01–3, 5 mg/l). These shoots were rooted on B5 and 1/2 MS media containing IAA or NAA, and the regenerated plants were transferred to soil and grown in a greenhouse. The emetic alkaloids of the regenerated plants, mother plants and leaves of shoot cultures were analyzed by TLC and HPLC. Seven months of growth under greenhouse condition, the contents of the emetic alkaloids in the regenerated plants were comparable to those of the mother plants.Abbreviations B5 Gamborg B5 (1968) medium - MS Murashige-Skoog (1962) medium - 1/2 MS a half strength MS medium - NAA 1-naphthaleneacetic acid - IAA indole-3-acetic acid - Kin kinetin - BA 6-benzylaminopurine - TLC thin layer chromatography - HPLC high performance liquid chromatography     

Molecular phylogeny of Japanese marine Tanytarsini chironomids (Chironomidae: Chironominae)

Genetica - Tanytarsini is a large tribe of Chironomidae with at least 11 recorded marine species grouped in three genera. In this study, we performed a phylogenic analysis using molecular data from...     

Focus: Allergic Diseases and Type II Immunity: Expression of Leucine-rich Repeat-containing Protein 32 Following Lymphocyte Stimulation in Patients with Non-IgE-mediated Gastrointestinal Food Allergies

The lymphocyte stimulation test (LST) facilitates the diagnosis of non-IgE-mediated gastrointestinal food allergies (non-IgE-GI-FAs). However, LSTs require large volumes of blood and prolonged culture durations. Recently, we found that IL2RA mRNA expression in peripheral blood mononuclear cells (PBMCs) of patients with non-IgE-GI-FAs increased after a 24 h stimulation with milk proteins. We designated this gene expression test as the instant peripheral blood allergen stimulation test (iPAST). In this study, we investigated whether other activated T cell-associated genes are superior to IL2RA in the iPAST for the supplementary diagnosis of non-IgE-GI-FAs. After incubating PBMCs with milk proteins for 24 h, the mRNA levels of three genes, LRRC32, TNFRSF4, and CD69, were assessed using quantitative RT-PCR. The diagnostic significance of the mRNA expression was evaluated by analyzing the receiver operating characteristic (ROC) curve. Upon stimulation with α-casein, κ-casein, α-lactalbumin, or a mixture of four milk protein components (Pmix), LRRC32 expression in the PBMCs of 16 patients with non-IgE-GI-FAs was found to be higher than that in their 17 control counterparts, whereas TNFRSF4 and CD69 levels remained unaltered. Except for β-lactoglobulin and cow’s milk (CM), the area under the ROC curve (AUC) for LRRC32 mRNA expression upon stimulation was >0.7, which validated the diagnostic ability of this test. Notably, α-casein and Pmix had higher AUC scores of 0.820 and 0.842, respectively, than other antigens. iPAST assessed by LRRC32 as well as IL2RA may be useful for the supplementary diagnosis of non-IgE-GI-FAs as an alternative to LSTs and provide insight into the pathogenesis of non-IgE-GI-FAs.     

Continous production of free gluconic acid by Gluconobacter suboxydans IFO 3290 immobilized by adsorption on ceramic honeycomb monolith: effect of reactor configuration on further oxidation of gluconic acid to keto-gluconic acid

Summary Gluconobacter suboxydans IFO 3290 was immobilized by adsorption on ceramic honeycomb monolith, and continuous production of free gluconic acid from 100 g/l glucose was carried out in one- and three-stage monolith reactors. Further oxidation of gluconic acid to keto-gluconic acid by the immobilized cells has been found to be more suppressed in the three-stage monolith reactor. This finding can be explained by the fact that, with the three-stage reactor, the opportunity to oxidize gluconic acid further was decreased because the residence time of the reaction mixture at glucose conversion above the threshold value was shorter.