Anaerobic biodegradability of polyvinyl alcohol

Summary Biodegradability of polyvinyl alcohol (PVA) under anaerobic conditions was demonstrated using anaerobic river sediments and anaerobically treated activated sludge from a sewage treatment plant. PVA having molecular weights of 2000 and 14000 was over 60% biodegraded as determined by TOC.     

Electron acquisition system constructed from an NAD-independent D-lactate dehydrogenase and cytochrome c2 in Rhodopseudomonas palustris No. 7

The activities of NAD-independent D- and L-lactate dehydrogenases (D-LDH, L-LDH) were detected in Rhodopseudomonas palustris No. 7 grown photoanaerobically on lactate. One of these enzymes, D-LDH, was purified as an electrophoretically homogeneous protein (M(r), about 235,000; subunit M(r) about 57,000). The pI was 5.0. The optimum pH and temperature of the enzyme were pH 8.5 and 50 degrees C, respectively. The Km of the enzyme for D-lactate was 0.8 mM. The enzyme had narrow substrate specificity (D-lactate and DL-2-hydroxybutyrate). The enzymatic activity was competitively inhibited by oxalate (Ki, 0.12 mM). The enzyme contained a FAD cofactor. Cytochrome c(2) was purified from strain No. 7 as an electrophoretically homogeneous protein. Its pI was 9.4. Cytochrome c(2) was reduced by incubating with D-LDH and D-lactate.     

Relationship between conidial enzymes and germination of the apple blue mold,Penicillium expansum

The relationship between conidial enzymes of Penicillium expansum and spore germination was examined. The activities of xylanase and pectinase, but not of cellulase and amylase, were detected in the conidia. The levels of xylanase and pectinase were greatly enhanced by xylan and pectin as respective carbon sources in the basal medium. No conidia germinated in the basal medium without a carbon source. The type of carbon source and the enzyme levels of the conidia did not affect the rate of germination. However, a relationship was found between the enzyme levels and the elongation of the germ tubes.     

Hydrogen Peroxide-Dependent Uptake of Iodine by Marine Flavobacteriaceae Bacterium Strain C-21

The cells of the marine bacterium strain C-21, which is phylogenetically closely related to Arenibacter troitsensis, accumulate iodine in the presence of glucose and iodide (I⁻). In this study, the detailed mechanism of iodine uptake by C-21 was determined using a radioactive iodide tracer, ¹²⁵I⁻. In addition to glucose, oxygen and calcium ions were also required for the uptake of iodine. The uptake was not inhibited or was only partially inhibited by various metabolic inhibitors, whereas reducing agents and catalase strongly inhibited the uptake. When exogenous glucose oxidase was added to the cell suspension, enhanced uptake of iodine was observed. The uptake occurred even in the absence of glucose and oxygen if hydrogen peroxide was added to the cell suspension. Significant activity of glucose oxidase was found in the crude extracts of C-21, and it was located mainly in the membrane fraction. These findings indicate that hydrogen peroxide produced by glucose oxidase plays a key role in the uptake of iodine. Furthermore, enzymatic oxidation of iodide strongly stimulated iodine uptake in the absence of glucose. Based on these results, the mechanism was considered to consist of oxidation of iodide to hypoiodous acid by hydrogen peroxide, followed by passive translocation of this uncharged iodine species across the cell membrane. Interestingly, such a mechanism of iodine uptake is similar to that observed in iodine-accumulating marine algae.     

Non-fucosylated therapeutic antibodies: the next generation of therapeutic antibodies

Therapeutic antibody IgG1 has two N-linked oligosaccharide chains bound to the Fc region. The oligosaccharides are of the complex biantennary type, composed of a trimannosyl core structure with the presence or absence of core fucose, bisecting N-acetylglucosamine (GlcNAc), galactose, and terminal sialic acid, which gives rise to structural heterogeneity. Both human serum IgG and therapeutic antibodies are well known to be heavily fucosylated. Recently, antibody-dependent cellular cytotoxicity (ADCC), a lytic attack on antibody-targeted cells, has been found to be one of the critical effector functions responsible for the clinical efficacy of therapeutic antibodies such as anti-CD20 IgG1 rituximab (Rituxan^®) and anti-Her2/neu IgG1 trastuzumab (Herceptin^®). ADCC is triggered upon the binding of lymphocyte receptors (FcγRs) to the antibody Fc region. The activity is dependent on the amount of fucose attached to the innermost GlcNAc of N-linked Fc oligosaccharide via an α-1,6-linkage, and is dramatically enhanced by a reduction in fucose. Non-fucosylated therapeutic antibodies show more potent efficacy than their fucosylated counterparts both in vitro and in vivo, and are not likely to be immunogenic because their carbohydrate structures are a normal component of natural human serum IgG. Thus, the application of non-fucosylated antibodies is expected to be a powerful and elegant approach to the design of the next generation therapeutic antibodies with improved efficacy. In this review, we discuss the importance of the oligosaccharides attached to the Fc region of therapeutic antibodies, especially regarding the inhibitory effect of fucosylated therapeutic antibodies on the efficacy of non-fucosylated counterparts in one medical agent. The impact of completely non-fucosylated therapeutic antibodies on therapeutic fields will be also discussed.     

Double knockdown of α1,6-fucosyltransferase (<Emphasis Type="Italic">FUT8</Emphasis>) and GDP-mannose 4,6-dehydratase (<Emphasis Type="Italic">GMD</Emphasis>) in antibody-producing cells: a new strategy for generating fully non-fucosylated therapeutic antibodies with enhanced ADCC

Background  

Antibody-dependent cellular cytotoxicity (ADCC) is greatly enhanced by the absence of the core fucose of oligosaccharides attached to the Fc, and is closely related to the clinical efficacy of anticancer activity in humans in vivo. Unfortunately, all licensed therapeutic antibodies and almost all currently-developed therapeutic antibodies are heavily fucosylated and fail to optimize ADCC, which leads to a large dose requirement at a very high cost for the administration of antibody therapy to cancer patients. In this study, we explored the possibility of converting already-established antibody-producing cells to cells that produce antibodies fully lacking core fucosylation in order to facilitate the rapid development of next-generation therapeutic antibodies.     

Isolation and characterization of microsatellite loci in a polyploid alpine herb,Callianthemum miyabeanum (Ranunculaceae)

• Premise of the study: Nuclear microsatellite primers were developed to analyze the clonal diversity and population genetic structure of the endemic polyploid herb Callianthemum miyabeanum. • Methods and Results: Using a protocol for constructing microsatellite-enriched libraries, 15 primer sets were developed for use in C. miyabeanum. The number of alleles found ranged from five to 22. The estimated range of expected heterozygosities was 0.574 to 0.907, and the Shannon–Weiner diversity index ranged from 1.061 to 2.733. Cross-amplification of all loci was also successful in the closely related endemic species C. kirigishiense and C. hondoense. • Conclusions: The development of these microsatellite loci will facilitate a deeper understanding of the genetic diversity, mode of reproduction, and population structure of not only C. miyabeanum, but also the other Callianthemum species endemic to Japan.